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  • Articles  (1,716)
  • General Chemistry  (837)
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  • 1980-1984  (1,716)
  • 1970-1974
  • 1981  (1,716)
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  • Articles  (1,716)
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  • 1980-1984  (1,716)
  • 1970-1974
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  • 1
    Electronic Resource
    Electronic Resource
    Vasculogenesis of the bursa cloacalis (bursa of Fabricius) of the chick embryo (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 35-42 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Vasculogenesis of the bursa cloacalis (bursa of Fabricius) was examined in 10- to 21-day chick embryos and in chicks during the first 5 days post-hatching. The entire circulatory system was injected with India ink, and the bursae were then removed and either cleared for examination in toto or sectioned serially. The bursa was supplied by three pairs of extrinsic blood vessels. At 10 and 11 days of incubation, most intrinsic vessels were arranged in a superficial, hexagonal network. In regions of developing plicae, the hexagonal plexus extended into the core of each plica, forming middle plical vessels. The latter were interconnected across interplical areas by cross-connecting vessels. The middle plical vessels gave rise to small capillary offshoots, which soon increased in complexity, forming delicate loops. Branches extended from these loops through the subepithelial lamina propria to incipient epithelial buds by 12 days of incubation. All epithelial buds were supplied by at least one such branch, and similar branches extended to the basal aspect of the epithelium in areas where epithelial buds had not yet formed. This observation is consistent with the hypothesis that blood vessels induce formation of epithelial buds. At about 15 days of incubation, the cortex and medulla of each developing lymphatic follicle were defined clearly, and an intricate, web-like, capillary network coursed throughout the follicular cortex. The medulla appeared to be devoid of capillaries. The diameters of all intrinsic and extrinsic bursal blood vessels gradually increased throughout development. During post-hatching stages, the diameters of the extrinsic vessels continued to increase, whereas those of the intrinsic vessels were markedly decreased from late pre-hatching stages.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051670104
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  • 2
    Electronic Resource
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    An investigation of the prolactin-thyroxine synergism in newt limb regeneration (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 103-108 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The use of hormone replacement to support limb regeneration in hypophysectomized newts has been the subject of many investigations. Growth hormone, as well as prolactin (PL) in combination with exogenously supplied thyroxine, have all been shown to he effective. However, the bovine growth hormone used to support limb regeneration was contaminated by prolactin and thyroidstimulating hormone (TSH). The present investigation evaluates the significance of (1) prolactin contamination and (2) endogenous thyroxine synthesis resulting from TSH contamination on limb regeneration in hypophysectomized newts. The effect of supplying exogenous thyroxine was also evaluated. Our studies showed that when hypophysectomized newts were injected with contamination levels of PL and TSH, regeneration occurred, suggesting that the newt's thyroid synthesized sufficient thyroxine to support a prolactin-thyroxine synergism. The endogenous thyroxine was synthesized by thyroid glands that were indistinguishable from those of saline-injected, hypophysectomized controls.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051670109
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  • 3
    Electronic Resource
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    The effects of androgens on the β-glands of the tokay (Gekko gecko): Modification of an hypothesis (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 109-118 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Study of the posterior abdominal epidermis in hypophysectomized/thyroidectomized male and female tokays following surgery, and subsequent androgen therapy, indicates that, contrary to a previous model, all aspects of β-gland differentiation are under direct androgenic control. On the other hand, another epidermal specialization, the digital foot-pad, shows a pattern of histogenesis directly comparable to that of β-glands, but is unaffected by androgens. These data are discussed with respect to the evolution of glandular epidermal specializations in gekkonid lizards and the possible role of androgens in modifying the control of cell differentiation in lizard epidermis.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051670110
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  • 4
    Electronic Resource
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    Ontogeny and phylogeny of tooth attachment modes in actinopterygian fishes (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 167-184 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: There are four major tooth attachment modes in actinopterygians. Type 1 mode is characterized by complete ankylosis of the tooth to the attachment bone; it is the primitive attachment mode for actinopterygians. In Type 2 mode there is a ring of collagen between the tooth base and the bone. In Type 3 mode mineralization extends near or to the bone at the anterior tooth border, and there is a relatively large collagen area on the posterior surface of the tooth; Type 3 teeth are hinged with an anterior axis of rotation. Type 4 teeth also have a relatively large posterior collagen area, but there is no collagenous connection between the anterior basal tooth border and the attachment bone; Type 4 teeth are hinged, with a posterior axis of rotation. Types 2, 3, and 4 attachment modes appear to result from retardation of mineralization and resemble, with some modifications, ontogenetic stages in the development of Type 1 mode; they are considered to be paedomorphic features. Attachment modes 2, 3, and 4 are each associated with a major evolutionary lineage within the Teleostei. The degree to which paedomorphosis has been a factor in teleostean evolution is discussed.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051670203
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  • 5
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    Heterochronic mechanisms of morphological diversification and evolutionary change in the neotropical salamander, Bolitoglossa occidentalis (Amphibia: Plethodontidae) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 249-264 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Bolitoglossa occidentalis, a lowland salamander of Mexico and Guatemala, has a highly derived morphology. The features that are derived with respect to the condition in generalized members of the genus include the following: (1) small body size; (2) short tail; (3) fully webbed hands and feet; (4) reduction and loss of certain phalangeal elements; (5) fusion of carpals and tarsals; (6) absence of prefrontal bones; and (7) reduced skull ossification. The ontogeny of this species was analyzed quantitatively and compared with the patterns of growth and differentiation encountered in two morphologically generalized members of the genus, B. rostrata and B. subpalmata. Most of the derived features can be explained by invoking a single heterochronic process: truncation of development at a small size (most likely the product of early maturation). Therefore, B. occidentalis is a paedomorphic species whose morphology has been attained through the process of progenesis. This result supports Alberch's ('80a) prediction, based on functional analysis, that the principle adaptation to arboreality in B. occidentalis is small size; other derived morphological features are associated with the organism's truncated development and may have no adaptive significance. However, patterns of dissociation are found within this overall progenetic process. Some of these include the following: (1) accelerated growth rates of the metatarsals and first phalanges, and retarded growth rates of the second and third phalangeal elements; (2) dissociation between rates of ossification of the skull and the autopodial elements; and (3) dissociation between the timing of termination of the process of shape change during the ontogeny of the foot (the product of differential growth between digital and interdigital areas) and termination of growth in overall foot size (foot surface area). This later result illustrates the independence of morphogenetic phenomena (shape change) from processes of growth (size increase).
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051670208
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  • 6
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    Embryonic stages of Gastrotheca riobambae (fowler) during maternal incubation and comparison of development with that of other egg-brooding hylid frogs (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 277-295 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A table of development (25 stages) for the period of incubation in the pouch was constructed for Gastrotheca riobambae; it can be used to stage embryos of other egg-brooding hylids. Analysis of embryonic weights during incubation shows that the mother does not contribute nutrients, but gases and other factors are probably exchanged between mother and embryos.According to species, incubation on the back of the mother is carried to the froglet or to the tadpole stages. Development in these hylids is characterized by specialized gills, the bell gills derived from the branchial arches. In some species, the bell gills derive from the first branchial arch and cover less than 50% of the embryo, while in others, the bell gills come from both branchial arches I and II and cover from less than 50% to 100% of the embryo. The most complex bell gills derive from the fusion of the two branchial arches.The majority of egg-brooding hylids live in tropical forests and carry development to the froglet stage. Tadpoles are produced by species of Flectonotus, Fritziana, and Gastrotheca. Tadpole-producing species of Gastrotheca have the most complex reproductive adaptations among egg-brooding hylids Acceleration and retardation in development seem to have played important roles in the evolution of these frogs. The evolutionary trend has been toward direct development, i.e., disappearance of the free-living larval stages through maternal incubation, and later to a recovery of the free-living tadpole stages in species of Gastrotheca with the most complex reproductive adaptations.
    Additional Material: 32 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051670303
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  • 7
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    Structure, histochemistry, ontogenetic development, and regeneration of the ocellus of Cladonema radiatum dujardin (cnidaria, hydrozoa, anthomedusae) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 313-331 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ectodermal eyes, 45-55 μm in diameter, of the cnidarian hydrozoan Cladonema radiatum Dujardin possess a lens approximately 15 μm in diameter enveloped by an eyecup (retina). An overlying layer of intensely vacuolated distal process of the adjoining epithelial cells forms a transparent cornea. The eyecup is composed of three cell types: basal cells, melanin-containing pigment cells, and photoreceptor cells. The last two cell types occur in the ratio of approximately 2:1. Histogenesis of the eye both during ontogeny and regeneration is described from light and electron microscopic investigations. During ontogeny the cell types forming the retina are derived from a compact group of morphologically undifferentiated cells, but during regeneration a primordium is formed by regeneration cells. In both cases the lens is built from distal nonnucleated cytoplasmic portions pinched off from the pigment cells. The cornea is formed by distal lamellar processes of the ocellus adjoining the epithelial cells. Through EM-histochemical methods (silver impregnation and DOPA-oxidase reaction) the pigment of the chromatophores of the retina was identified as melanin.
    Additional Material: 25 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051670306
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  • 8
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    Announcement (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 247-247 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051680211
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  • 9
    Electronic Resource
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051680301
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  • 10
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    Patterns of olfactory projections in the desert iguana, Dipsosaurus dorsalis (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 189-227 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The neural organization of the olfactory system in the desert iguana, Dipsosaurus dorsalis, has been investigated by using the Fink-Heimer technique to trace the efferents of the main and accessory olfactory bulbs, and Golgi preparations to determine the spatial relations between olfactory afferents and neurons in the primary olfactory centers.The accessory olfactory bulb projects to the ipsilateral nucleus sphericus via the accessory olfactory tract. The main olfactory bulb projects to the ipsilateral telen-cephalon via four tracts. The medial olfactory tract projects to the rostral continuation of medial cortex and to the septum. The intermediate olfactory tract projects to the olfactory tubercle and retrobulbar formation. The lateral olfactory tract projects to the rostral part of lateral cortex. The intermediate and lateral olfactory tracts also merge caudally to form the stria medullaris, which crosses the midline in the habenular commissure and distributes fibers to the contralateral hemisphere via two tracts. The lateral corticohabenular tract terminates in the contralateral lateral cortex. The anterior olfactohabenular tract terminates in the contralateral olfactory tubercle, retrobulbar formation and septum.The relation of olfactory afferents to neurons in the medial cortex, lateral cortex, nucleus sphericus, and septum corresponds to a pattern of organization that is typical of many olfactorecipient structures. Such structures are trilaminar, with neurons whose somata are situated in the intermediate layer (layer 2) sending spine-laden dendrites into an outer, molecular layer (layer 1). Olfactory afferents intersect the distal segments of these dendrites. By contrast, other olfactorecipient structures in Dipsoaurus deviate from the familiar pattern. Olfactory afferents intersect somata lying in layer 2 of the retrobulbar formation. Olfactory afferents include some fibers which course perpendicularly to the surface of the olfactory tubercle and extend deep to layer 2.
    Additional Material: 22 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051680208
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  • 11
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    Observations on preadipocytes and their distribution patterns in rat adipose tissue (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 281-288 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Microscopic examination of adipocytes isolated from adult rat epididymal adipose tissue revealed numerous small cells (〈 10 μm) morphologically similar to larger adipocytes. These small adipocytes appear identical to a new classification of adipose cells termed preadipocytes. Electron micrographs of these preadipocytes revealed examples of cells 〈 10 μm in diameter in various stages of maturation and lipid accumulation. The percent distribution pattern of these small adipocytes was not significantly altered by exercise although exercise shifted the distribution patterns of the larger cells (〉 30 μm) toward a smaller mean cell size. The quantitative significance of preadipocytes is not established but these preliminary observations indicate that adipocytes 〈 10 μm in diameter may account for a numerically greater proportion of the total adipocytes observed in collagenase isolated preparations than heretofore recognized, although their contribution to total adipose mass is probably negligible.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051680304
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  • 12
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    Hormone dependent changes in the apical connective tissue during early stages of forelimb regeneration in the hypophysectomized newt, Notophthalmus viridescens (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 297-308 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When a newt is hypophysectomized prior to or at the time of forelimb amputation a dermal barrier eventually forms between the apical cap of epithelium and the underlying mesenchymal tissues, and the typical regeneration response is transformed to a wound-healing morphology. When hypophysectomized newts are injected on continuous alternate days beginning either at the time of amputation or following a fifteen-day delay, with either growth hormone (GH) or prolactin in combination with thyroxine (PLT4), normal regeneration occurs. Our experiment was designed to examine critically the early changes occurring in apical connective tissue that had been allowed to form as a consequence of hypophysectomy prior to forelimb amputation. Adult newts were hypophysectomized and five days later both forelimbs were amputated distal to the elbow. Following a delay of eight days, to permit the formation of connective tissue beneath the apical epithelium, they were injected intraperitoneally on successive alternate days with GH or with PL in combination with T4 in the aquarium water. The apical connective tissue of the limb stumps underwent a progressive erosion and became discontinuous by day 4. The limb morphology of hypophysectomized newts receiving ACTH or PL or maintained in thyroxine was virtually identical to sham-injected hypophysectomized controls. It appears that an initial effect of GH or PLT4 therapy is to establish the epithelial-mesenchymal interface that previously has been suggested to be a requisite for the regenerative event.
    Additional Material: 15 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051680306
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  • 13
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    External features of embryonic development of a jumping bristletail, Pedetontus unimaculatus Machida (Insecta, Thysanura, Machilidae)Contributions from Sugadaira Montane Research Center, University Of Tsukuba, no. 56. (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 339-355 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The external features of the embryo and the first instar larva of Pedetontus unimaculatus are described. Blastokinesis of P. unimaculatus is very similar to that of Petrobius brevistylis (Larink, '69), but differs from that of Machilis alternata (Heymons and Heymons, '05). The superficial structures of three pairs of protocerebral lobes are present. The terga of the mandibular, maxillary, and labial segments take part in the formation of the head capsule. In the maxilla and labium, the palpi are homologous with the telopodites of the legs; the other parts proximal to the palpi are homologous with the coxopodites. No sternal element contributes to the postmentum. Both glossa and paraglossa consist of two lobes. The pleuropodium, stylus and ventral sac are derived from distal parts of appendage anlagen. The pleuropodium of the first abdominal segment is homologous with the styli of the successive abdominal segments; the ventral sacs of succeeding segments are serially homologous. The basal parts of appendage anlagen cover each sternum in the first to ninth abdominal segments to form coxites, which are therefore appendicular in origin. The basal part of the cercus also covers the ventral and lateral surfaces of the eleventh abdominal segment.
    Additional Material: 42 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051680310
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  • 14
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    The embryonic development of the primitive moth, Neomicropteryx nipponensis Issiki (lepidoptera, micropterygidae): Morphogenesis of the embryo by external observation (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 49-59 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The micropterygid moth Neomicropteryx nipponensis belongs to the most primitive suborder Zeugloptera of the Lepidoptera. During embryogenesis the small circular germ disk formed on the ventral egg surface invaginates deeply into the yolk. It finally separates from the egg periphery or rudimentary serosa, and becomes a sac-shaped germ rudiment. Its anterior part later develops into the germ band, while its posterior part is the future amnion. Just before revolution of the embryo, the embryo assumes a completely superficial position beneath the yolk. Neither amnion nor serosa rupture during revolution; by completion of dorsal closure they have been incorporated into the yolk to form the secondary dorsal organ.The formation of the germ rudiment and embryonic membranes in N. nipponensis resembles those of swift moths, Endoclyta (suborder Monotrysia) and of the caddisflies, Stenopsyche (Trichoptera), but differs from those of ditrysian Lepidoptera. The secondary dorsal organ has never been found in any other lepidopteran embryos; however, it is formed in N. nipponensis and in the Trichoptera. The results of the present study strongly support the general phylogenetic views that the Zeugloptera have a close affinity to the Trichoptera.
    Additional Material: 25 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051690105
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  • 15
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051690101
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  • 16
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    Ultrastructure of the lung of the rattlesnake, Crotalus viridis oreganus (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 29-47 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Scanning and transmission electron microscopic observations were made on the rattlesnake lung, which has the form of a cigar-shaped bag enclosing a large axial air chamber. The lungs were fixed by tracheal instillation of fixative to preserve the structural features of inflated lungs. An open tracheal groove along the ventral aspect of the lung is the only structural “airway” present. The wall of the lung has two histologically distinct regions: anteriorly, a respiratory portion, where up to three generations of septa subdivide the wall into cup-shaped gas-exchange chambers, termed faveoli; and posteriorly, a simple, thin-walled saccular portion. The epithelium lining the internal surface of the lung is composed of several cell types: (1) ciliated cells; (2) type I pneumonocytes; (3) type II pneumonocytes, secretory cells characterized by the presence of lamellar bodies; and (4) serous epithelial cells, secretory cells characterized by the presence of homogeneous, densely staining secretory granules. However, the distinctiveness of the secretory cell types in the snake lung is blurred because intermediate-appearing cells have both the lamellar body and homogenous type of secretory granule. The nonepithelial components of the pulmonary wall and septa consist of blood vessels and lymphatics, smooth muscle cells and fibroblasts, embedded in a matrix of extracellular connective tissue fibers. Tubular myelin figures were observed in the faveolar lining layer.
    Additional Material: 22 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051690104
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  • 17
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    Olfactory bulb efferents in the channel catfish, Ictalurus punctatus (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 91-111 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Autoradiographic, HRP, and Fink-Heimer techniques define olfactory bulb efferents in the channel catfish. The olfactory bulb projects bilaterally to eight targets in the area ventralis telencephali including the preoptic area, five targets in area dorsalis telencephali, and the posterior tuber of the diencephalon. There is additional input to the peripheral margin of the internal cell layer of the contralateral olfactory bulb. Fibers cross in rostral (nervus terminalis and commissure of Goldstein) and caudal components of the anterior commissure and the habenular commissure. HRP techniques reveal the origin of bulb efferents from the internal and mitral cell layers of the olfactory bulb. The olfactory tract is divided into five major components, each with a unique subset of ipsilateral and commissural pathways.
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    URL: http://dx.doi.org/10.1002/jmor.1051690108
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  • 18
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    Establishment of the site of involution at novel locations on the amphibian embryo (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 149-159 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Anuran (Rana) and urodele (Ambystoma) amphibian eggs were subjected to prolonged unnatural orientations in relation to gravity. In some cases eggs were rotated 90°, while in other instances eggs were rotated 180° (complete inversion). Alterations in the pigmentation pattern, cleavage pattern, and site of involution were observed. Despite these unnatural orientations to gravity, the morphogenesis of axial structures was frequently normal. Reorganization of the egg cytoplasm apparently takes place after the unnatural orientation. Rather than being localized in a fixed position in the egg (e.g., the egg cortex), the determinants for the pattern of early embryogenesis are probably located in that portion of the cytoplasm (e.g., “internal” cytoplasm) that orients to gravity.
    Additional Material: 15 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051690203
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  • 19
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    The cytoarchitecture of the torus semicircularis in the red-eared turtle (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 207-223 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cytoarchitecture and neuronal morphology of the torus semicircularis in the red-eared turtle, Chrysemys scripta elegans, were examined in Nissl-stained and Golgi-impregnated material. The torus semicircularis begins in the caudodorsal mesencephalon and extends rostrally and laterally to end ventrally to the tectal ventricle. The torus semicircularis consists of a central nucleus and a laminar nucleus, which is interposed between the central nucleus and the ventricle.The central nucleus can be divided into two regions, a small, large-celled area, located dorsally, and a larger area of small spherical (6-17 μm), large spherical (18-25 μm), triangular (15-27 μm) and fusiform (10-26 μm) neurons. The small spherical cells have two dendritic patterns: “radiate” and “single.” The radiate pattern has a dorsoventral orientation, several secondary branches and few dendritic spines. These cells are usually located in the center of the central nucleus. The single pattern is oriented mediolaterally. This cell type is most often observed at the periphery of the central nucleus. These neurons have few secondary branches and dendritic spines. The large spherical neurons display two dendritic orientations: dorsoventral and mediolateral. All dendritic trees have numerous secondary branches and few dendritic spines. The triangular neurons exhibit primary dendrites projecting from the corners of the somata and have few secondary branches and dendritic spines.The fusiform neurons have a majority of their dendrites oriented mediolaterally, few secondary branches and a small number of dendritic spines.The laminar nucleus consists of several layers and three cell types: ovoid (9-15 μm), triangular (20-40 μm), and fusiform (20-40 μm). All neurons have few secondary dendritic branches and few dendritic spines. The dendrites of many neurons course perpendicularly to the long axis of the brainstem and encapsulate the central nucleus. Some ovoid and fusiform neurons display dendrites that enter the central nucleus.
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    Observations on the morphology and histochemistry of the foregut muscles of spiders (Arachnida: Araneida) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 113-131 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of the foregut muscles of five spider families (Theraphosidae, Agelenidae, Araneidae, Lycosidae, Salticidae) was described, and the individual fibre numbers and fibre cross diameters of the muscles were determined. The nomenclature of these muscles was reviewed and modified if necessary.Oxidative enzyme and myosin-ATPase histochemistry revealed eight dilatatory muscles of the foregut to consist of slow (type I) fibres, while fast fibres (type IIB), and intermediate fibres, were only to be found in the two other muscles of the foregut, and in the remaining prosomal muscles (type IIA fibres around the poison gland).The eight sucking muscles proper of the foregut also showed stronger activities of transmitter metabolizing enzymes [monoamine oxidase, glutamate dehydrogenase(NAD)], and comparatively distinct amounts of glycogen and lipids.
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    URL: http://dx.doi.org/10.1002/jmor.1051700108
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    An electron microscopic study on the innervation of the gill filaments of a lamprey, Lampetra japonica (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 325-336 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper reports observations on the innervation of gill filaments of the lamprey, Lampetra japonica. Nerve fibers run on each side of the afferent filament artery (AFA nerve) and in the connective tissue compartment along the efferent filament artery (EFA nerve). The AFA nerve supplies vasomotor fibers to the afferent filament artery and arteriovenous anastomoses and special visceral motor fibers to branchial muscle fibers (musculus compressor branchialis circularis). Nerve endings of the vasomotor fibers contain large, cored vesicles (60-180 nm in diameter) with a variable number of small, clear vesicles (30-70 μm in diameter), whereas those of the visceral motor fibers have many small, clear vesicles with few large, cored vesicles. The EFA nerve supplies vasomotor fibers to the efferent filament artery. Their endings, containing mixtures of predominantly large, cored vesicles and small, clear vesicles make close synaptic contacts with reticular cells. The latter in turn are connected with each other or with smooth muscle cells in the wall of the efferent filament artery by nexuses. No nerves are found in the axial plate between the afferent and efferent filament arteries nor in the secondary lamellae of individual gill filaments. No afferent nerve supply to the gill filament has been found.
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    URL: http://dx.doi.org/10.1002/jmor.1051690306
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    Morphology of soma and dendrites of the giant fiber system in the sixth abdominal ganglion of the cockroach (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 351-355 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study, using the cobalt chloride technique, clarifies the origin of the giant axons in the cockroach, Periplaneta. Each giant axon in the ventral nerve cord arises from a single cell body located in the sixth abdominal ganglion. The position of the soma is always contralateral to the giant axon; it projects anteriorly. In six giant neurons, the axonic and dendritic branches are ipsilateral while the somata are contralateral. In two neurons, both the soma and the dendritic branches are ipsilateral while the axons are contralateral. The dendritic arborizations of the giant neurons form a dense and compact mass of neuropile in each half of the posterior and middorsal part of the ganglion where sensory fibers, primarily from the cercal nerves terminate. The relation of these findings to earlier electrophysiological studies is discussed.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051700101
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    Limb regeneration following the discontinuation of growth hormone therapy in the hypophysectomized newt, Notophthalmus viridescens (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 309-319 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Untreated adult newts do not undergo normal limb regeneration following hypohysectomy. A fibrocellular dermal barrier (cicatrix) atypically forms between the apical epithelium and the underlying mesenchymal tissues. Historically, continuous administration of growth hormone or of prolactin in combination with thyroxine restored regenerative capacity to these newts. In a previous investigation, we demonstrated that the initial effect of these two hormone treatments, when administered on alternate days to hypophysectomized newts beginning eight days post-amputation, was to facilitate the erosion of the fibrocellular barrier and establish the epithelial mesenchymal interface that is observed in a regenerating limb.The present investigation was designed to evaluate the necessity of continuous hormone therapy to maintain limb regeneration in hypophysectomized newts. One, two, or three injections of growth hormone or of prolactin in combination with thyroxine was administered on successive alternate days to hypophysectomized newts either immediately following limb amputation (ID) or beginning eight days post-amputation (DD). The ID and DD newts receiving one, two, or three injections of growth hormone showed evidence of regeneration to the digitiform stage by day 30 post-amputation, while those receiving prolactin and thyroxine underwent wound healing. While both hormone treatments initially promoted a dermis-free apical epithelium, only hypophysectomized newts that had received growth hormone were able to continue regenerating.We have, therefore, concluded that discontinuous growth hormone therapy is sufficient to initiate and maintain the conducive environment for limb regeneration to advanced stages in the hypophysectomized newt. While initiating this process, prolactin and thyroxine therapy on a discontinuous regime does not maintain regeneration. The direct and indirect role of growth hormone in supporting limb regeneration in normal and hypophysectomized newts is discussed.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051700301
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    Organization of the telencephalon in the channel catfish, Ictalurus punctatus (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 71-90 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cytoarchitectonics of the telencephalon of the channel catfish, Ictalurus punctatus, are described as a basis for experimental analysis of telencephalic afferents and efferents. The olfactory bulb comprises: (1) an outer layer of olfactory nerve fibers, (2) a glomerular layer, (3) an external cell layer, (4) an inner fiber layer, and (5) an internal cell layer. The telencephalic hemispheres comprise the areas ventralis and dorsalis telencephali. The area ventralis consists of: (1) a precommissural, periventricular zone including nucleus 'nother (Vn), the ventral nucleus (Vv), and the dorsal nucleus (Vd); (2) a precommissural, migrated zone of central (Vc) and lateral (VI) nuclei; (3) a supracommissural nucleus (Vs); (4) a caudal commissural zone of postcommissural (Vp) and intermediate (Vi) nuclei; and (5) a preoptic area (PP). The area dorsalis comprises: (1) medial (DM), (2) dorsal (Dd), (3) lateral [DL, containing dorsal (DLd), ventral (DLv), and posterior (DLp) regions], (4) posterior (DP), and (5) central (DC-1, -2, -3) areas. Nucleus taeniae (NT) is transitional between areas dorsalis and ventralis.
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    Larval morphology of the Nemertean Carcinonemertes epialti (Nemertea: Hoplonemertea) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 61-70 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of the newly hatched larva of Carcinonemertes epialti Coe has been examined by light and electron microscopy. The newly hatched larva is covered with cilia and measures about 110 μm in length. Four types of epidermal cells are recognizable: (1) Multiciliated cells, (2) vacuolated cells, (3) mucous cells, and (4) “knob cells”. The knob cells protrude from the posterior end of the larva and contain granules and bundles of microfilaments. The gut is incomplete and is located ventral to the bipartite proboscis. A bilobed brain and two subepidermal ocelli are found in the anterior end of the larva. The anterior and posterior cirri are composed of long, tightly appressed cilia that arise from an invagination of the epidermis at each end of the larva. The anterior cirrus is surrounded by two types of glandular cells. It is proposed that the knob cells have a role in larval attachment, combining the functions of the adhesive cells and anchor cells described in the duo-gland system of turbellarians. The cirri are believed to be larval sensory structures that function in substrate selection. Histological and ultrastructural observations suggest that the larvae of Carcinonemertes are relatively long lived and develop into juveniles without a drastic metamorphosis.
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    Carbohydrates in the webs of Argiope spiders (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 141-148 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Glycoproteins are present in the web of the orb-weaving spiders Argiope trifasciata and Argiope aurantia. Periodic acid-Schriff reactive glyco-proteins are confined in large part, to the sticky spiral and sticky spiral-radial junctions. Glycoproteins containing amino sugars appear associated with all fibers, especially the radial fibers. Enzymes may be used to remove glycoproteins selectively from the sticky spiral and stabilimentum.
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    Morphology of the pineal organ in the salamander Ensatina eschscholtzi (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 191-206 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The pineal organ of Ensatina eschscholtzi, a terrestrial and secretive species of salamander of the family Plethodontidae, is a photoreceptive structure lying on the dorsal surface of the diencephalon. The pineal is flattened with a broad lumen and consists of three cell types: photoreceptors, supportive cells, and neurons. Pineal photoreceptors are typical vertebrate photoreceptors and possess outer segment formations which, however, are frequently contorted and disorganized. Sloughing of apical portions of outer segments and vesiculation along the lateral edges of outer segment membrane disks are consistently observed and presumed to represent mechanisms of outer segment membrane recycling. Photoreceptors have basal processes which synapse with neural dendrites. Synapses between photoreceptor basal processes are occasionally observed. All synapses are characterized by synaptic ribbon structures of variable number, size, and configuration. Dense-core vesicles are occasionally observed mingled with clear synaptic vesicles within photoreceptor basal processes. Supportive cells within the pineal function in phagocytosis and recycling of shed outer segment membrane material, and neurons are localized at the lateral margins of the organ. The latter send axons into the ipsilateral side of the dorsal diencephalon. The pineal organ of Ensatina shows marked variation in overall size (cell total), cell type proportions, absolute neuron number, and ratio of photoreceptor number to neuron number for individual pineals. None of these morphological parameters is correlated with body size, sex, or season, and it is assumed that such variability represents significant variation in photosensory capabilities. It is suggested that the pineal organ of Ensatina is a partially degenerate photoreceptive structure.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/jmor.1051690301
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    A Study of the influence of the ambient microflora on the structure of lung alveolar macrophages and an ultrastructural comparison of lung and peritoneal macrophages in germ-free and conventionally reared mice (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 283-291 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In order to investigate quantitatively and objectively the influence of the normal microbial flora on the ultrastructure of the alveolar macrophage, three groups of mice were studied stereologically: germ-free (GF), conventionally reared under non sterile isolation conditions (IC), and conventionally reared in an open environment (OC). The alveolar macrophages of GF mice possess a smaller mitochondrial compartment, possibly with fewer organelles, than the macrophages of conventional mice. Other influences of the normal microflora on alveolar macrophage substructure are obscured by the effects of nonmicrobial stimuli such as droplets of lung surfactant.No previous comparison exists of alveolar and peritoneal macrophage ultrastructure. Lung macrophages are larger than the phagocytes of the peritoneum, but the difference in size is much less than is commonly believed. Alveolar macrophages are rounder than peritoneal macrophages, and exhibit much less rough endoplasmic reticulum (RER) as well as differences in mitochondrial morphometry. No difference in mitochondrial volume fraction exists between the two types of macrophage even though alveolar macrophages represent the extreme of aerobic adaptation in the mononuclear phagocyte system. Phagosomes occupy a significant fraction of cellular volume only in the alveolar macrophages. Moreover alveolar phagocytes contain fewer but larger lysosome-like granules than are found in peritoneal macrophages. The results represent the first objective, quantitative structural evidence confirming the common belief that alveolar macrophages experience greater physiological stimulation than peritoneal macrophages. The normal microflora accounts for only a small proportion of the differing degree of stimulation exerted on the two types of macrophage.
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    Comparative analysis of the development of the lizard, Liolaemus tenuis tenuis. II. A series of normal postlaying stages in embryonic development (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 337-349 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this work, we have completed a study of the development of the ovoviviparous lizard Liolaemus tenuis tenuis. Ovoviviparity in this lizard is a condition in which eggs are retained within the reproductive duct for about 60 days. During this period the phases of segmentation, gastrulation, neurulation, presomitic, and somitic embryos transpire. During the months of December and January the eggs are laid, and at this time the embryos are comparable to stage 27 Liolaemus gravenhorsti lizard embryos, or to stage 29 Calotes versicolor lizard embryos. Differentiation of the facial region occurs between Days 12 and 42 after egg laying. Limbs develop rapidly between the 8th and 23rd days. By 53 days the appendicular skeleton is completely formed. After 36 days the mesonephros begins to degenerate, and its function is gradually taken over by the developing metanephros. Newborn lizards do not possess an egg caruncle. During the period up to hatching, there is a great increase of liquid within the egg, presumably amniotic fluid. Cracks develop in the leathery shell shortly before hatching and are, perhaps, the first sign of the onset of hatching. Increase of liquid in the egg during postlaying development accounts for its increase in weight and change in shape. Weight of the embryo at hatching does not exceed 32% of the total weight of the egg.
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    Comparative cardiac anatomy of the reptilia. IV. The coronary arterial circulation (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 1-27 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The coronary arterial supply and associated structures have been examined and described for 29 species covering 11 reptilian families, with supplementary observations on other species. Variation in the origin, number, and configuration of coronary arterial vessels is mainly interfamilial and the same is true regarding the presence or absence of a gubernaculum cordis. It is suggested that the presence of a hitherto unrecognized intertruncal branch of the coronary artery has been responsible for much of the alleged intrafamilial variation reported in earlier literature. A general review of the cardiac blood supply and coronary arterial supply of other lower vertebrates is presented and used as a basis for interpreting phyletic and functional aspects of the reptilian conditions.
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    Histochemistry of lower vertebrate calcified structures. I. Enamel of the dogfish Squalus acanthius compared with mammalian enamel and homologous dentine (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 95-111 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The enameloid and dentine of Squalus acanthius have been compared histochemically with those of Bos taurus. Squalus enameloid is much less reactive to a variety of stains or reagents than dentine or bovine immature enamel but it does have positive reactions with picromethyl blue, Mallory's and Van Gieson's stains, and Alcian blue. It stains faintly with Biebrich scarlet, indicating some anionic groups. Specific reactions for tyrosine, tryptophane, lysine, histidine, arginine, and cysteine are negative. Bos immature enamel is positive for cationic, anionic, and aromatic reactive groups by all test procedures, and dentine was positive for the anionic components. Bovine maturing enamel, however, is more similar in terms of lack of reactivity to Squalus enameloid but differed because the bovine enamel was moderately positive for tyrosine; tryptophane, and anionic groups and negative with Mallory's picromethyl blue and Van Gieson's stains. A fibrous transitional area between Squalus dentine and enameloid has staining reactions characteristic of both collagen and keratins.
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    Consequences of cell death after nitrogen mustard treatment on skeletal pelvic fin morphogenesis in the trout, Salmo gairdneri (Pisces, teleostei) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 181-194 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Five concentrations of nitrogen mustard (methyl-bis-chlorethylamine) have been administrated to different stages of development of trout embryos (Salmo gairdneri), in order to study their effect on the formation of both pelvic fins soft tissue and skeleton. Sensitivity of epidermis and mesoderm toward this cytotoxic agent has been assessed histologically. Although both components are sensitive to nitrogen mustard, mesoderm is more sensitive than epidermis. These results are compared with the results of similar studies on tetrapod limb buds. The pelvic fin skeleton of some treated animals was doubly stained in toto for cartilage and bone by Alcian blue and alizarin, followed by clearing. Other specimens were processed for histological serial sections. Analysis included comparison of the following parameters: (1) dose of nitrogen mustard, (2) stage of fin bud development at the time of treatment, (3) importance of necrosis in the fin bud, and (4) abnormalities of the endoskeleton of the fin (pelvic girdle and radials) and of the dermal skeleton (lepidotrichia and actinotrichia) one month after the hatching of control animals. Results suggest (1) that material of endoskeleton and lepidotrichia are laid down simultaneously, and (2) that differentiation of actinotrichia is independent of differentiation in endoskeleton and lepidotrichia.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051680201
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    Experimental regeneration of the caudal skeleton of the glass knifefish, Eigenmannia virescens (Rhamphichthydae, Gymnotoidei) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 121-135 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper describes the regeneration of the caudal axial skeleton after amputation of the tail, including about 20 vertebrae, in the gymnotoid fish Eigenmannia virescens. Seven days after amputation, a regeneration blastema developed and soft tissues degenerated. A cylinder of cartilage developed at the end of the notochord. When this cartilage was about 10 mm long (21 days), perichondral ossification began. The cartilage continued to elongate and ossification increased while osteoclasts began to destroy the cartilage ventrally. Finally, a bony rod formed and at its tip the cartilage persisted as a rod, 2 to 3 mm long. The anal fin also regenerated: Endoskeletal cartilage developed first, following by differentiation of the lepidotrichia, and finally ossification of the endoskeleton.
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    Buoyancy adaptations in a swim-bladderless Antarctic fish (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 91-102 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The endemic Antarctic teleosts of the suborder Notothenioidei are bottom dwellers. They lack swim bladders, are heavier than seawater, and feed on or near the bottom. The midwaters surrounding the Antarctic continent are productive and underutilized by fishes. There is an evolutionary trend toward pelagism in some notothenioids. We discovered that the largest Antarctic fish, Dissostichus mawsoni, was neutrally buoyant. Attainment of neutral buoyancy was associated with specializations of the skeletal, integumentary, muscular, and digestive systems. The skeleton had a low mineral content and contained considerable cartilage. Scales were also incompletely mineralized. Static lift was obtained from extensive lipid (mostly triglyceride) deposits. A 2-8 mm subcutaneous lipid layer accounted for 4.7% of the body weight. White muscle also contained much lipid-23% on a dry weight basis, or 4.8% of the body weight. Microscopic examination suggested that the liver was active in lipid metabolism, although it was not an organ of buoyancy. Stellate (perisinusoidal) cells with many lipid droplets were a very prominent cytological component of the liver. These specializations made Dissostichus neutrally buoyant and capable of inhabiting the food-rich Antarctic midwaters.
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    Correlation of cyclic GMP and cyclic AMP immunofluorescence with cytochemical patterns during dormancy release and development from gemmules in Spongilla lacustris L. (Porifera: Spongillidae) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 53-63 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The spongillid freshwater sponges asexually produce an encapsulated dormant stage, the gemmule. With release from dormancy, internal, yolk-laden, binucleate thesocytes differentiate into histoblasts or archeocytes. The histoblasts emerging first from the gemmule form the initial pinacoderm of the hatching sponge. Immunohistochemistry was employed to examine the distribution of cyclic GMP (cGMP) and cyclic AMP (cAMP) following dormancy release and during gemmule germination and hatching in the freshwater sponge, Spongilla lacustris L. Cyclic nucleotide fluorescence patterns were analyzed in relation to the distribution of cytochemically demonstrable macromolecular constituents and intracellular organelles. Twenty-four hours following temperature-activated release from dormancy, cGMP fluorescence levels are elevated in thesocytes at the gemmule periphery prior to histoblast formation. The cAMP fluorescence in the gemmule also occurs first in those thesocytes differentiating into histoblasts. Cytochemical patterns in germinating gemmules are comparable with those described by Ruthmann ('65) and Tessenow ('69). However, cytochemically demonstrable events of cytodifferentiation follow the earlier appearance of cGMP and cAMP in the histoblast precursors by approximately 12 hours. In addition, cGMP appears to be associated with the membranes of cytoplasmic organelles, possibly lysosomes or lipid inclusions, in the region of vitelline platelets and with symbiotic algae. cAMP is located primarily on the membranes of the vitelline platelets and on membranes of vacuoles involved in forming the spicular skeleton These observations suggest that cGMP and cAMP are involved in the mobilization of nutrient reserves and in ion transport during dormancy release and development from gemmules in freshwater sponges.
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    The cranial nerves of the teleost Trichiurus lepturus (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 119-134 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cranial nerves of the cutlassfish, Trichiurus lepturus, were described from their external brain origin to their most distal points. The nervus olfactorius, nervus opticus, nervus oculomotorius, nervus trochlearis, nervus abducens, nervus glossopharyngeus, and nervus vagus of Trichiurus are characteristic of teleosts. The cephalic autonomic nervous system also follows the general scheme for teleosts.Atypical patterns are exhibited by portions of the ramus mandibularis facialis, ramus mandibularis trigemini, nervus stato-acusticus, and nervus lineae later-alis. A cutaneous ramus mandibularis externus facialis arises from the ramus mandibularis; this cutaneous nerve has been recorded specifically in only certain siluroid catfish. A connection from the ramus mandibularis trigemini to the cutaneous ramus mandibularis externus facialis is present; an equivalent of this connection has been reported only in the silversides, Menidia, and the siluroid catfish Parasilurus. This nerve pattern probably represents an archaic arrangement. The nervus stato-acusticus of Trichiurus is typical for teleosts, except for a branch extending from the posterior part of the nerve; this branch sends connections to the nervus lineae lateralis and then exits the cranium via the vagus foramen. Connections between the nervus lineae lateralis and the nervus stato-acusticus have previously been reported in only the hatchetfish, Argyropelecus, and the bristle-mouth, Cyclothone. This condition may represent a specialized adaptation of certain mesopelagic teleosts having extreme vertical-migration capabilities.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051670301
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    Morphological evidence for probable secreting site for the pheromone “seducin” in males of Nauphoeta cinerea. I. Light microscope studies (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 229-237 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Males of the cockroach, Nauphoeta cinerea (Olivier), possess a thickened secretory epithelium limited to the inner surfaces of sternites three to seven and tergites two to eight. The epithelium consists of three cell types: 1. large columnar secretory cells, 2. squamous nonsecretory cells, and 3. duct cells. Type 1 cells constitute the innermost layer and contain large nuclei and vacuoles, which are especially prominent in the epidermis of older males. This cell type may be involved in “seducin” secretion. Type 2 cells lie in the narrow basophilic zone which separates the secretory cells from the cuticle. Here, cellular boundaries are poorly defined. Type 3 cells with condensed nuclei are associated with cuticular ductules leading from the epidermis to the exocuticle. The epidermal height in the secretory zone of the sclerites approaches 40-200 μm depending on the age of the male. The changes in appearance of the secretory cells (increase in height and vacuolation) indicate heightened secretory activity. This is supported by the results obtained when extracts of these regions from different aged males are bioassayed for pheromone (Dimeo et al., '78). A striking difference in the morphology of the cuticle and epidermis of the secretory halves of sternite and tergal integument is noticeable.
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    A quantitative analysis of mitotic gradients during early development in Calliphora erythrocephala Meig. (Diptera) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 239-245 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mitotic waves during superficial cleavage and early gastrulation were analyzed quantitatively in Calliphora. Three consecutive patterns are present: (1) a monotonic anterioposterior mitotic gradient during early superficial cleavage; (2) a double mitotic gradient from the anterior and posterior poles during superficial cleavage, especially toward the end of the period; and (3) more complicated patterns with intermediate mitotic centers during the last superficial cleavage division and during early gastrulation. Mitotic gradients are absent in many eggs during early superficial cleavage, but they then become ubiquitous. The gradients are longitudinal; no transverse component was detected before gastrulation. Anterior and posterior gradient patterns are not mirror images of each other; mitotic activity always starts earlier anteriorly. The gradients are accompanied by a pronounced increase in interphase length. The mitotic gradients are compared with the morphogenetic gradients predicted in a current model for pattern specification in insect eggs.
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    Digital morphology in Varanus and Iguana (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 289-295 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Marked tendinous bands lie along the lateral sides of the fingers in Varanus and Iguana and have asymmetrical roots in the metacarpal region. The radial band of each finger represents the distal extension of an oblique band arising at an ulno-dorsally located line in the proximal part of the metacarpal, whereas the ulnar bands each form a tendinous extension of an interosseus muscle bundle. The function of this metacarpo-digital system must be seen in relation to the deformations of the hand, imposed during locomotion by longitudinal rotation of the forearm. The latter motion results from the foreward and backward sway of the humerus with the elbow bent at 90°.
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    Microanatomy of the renal cortex in the domestic fowl (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 249-267 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two aspects of the avian renal cortical microanatomy previously were unclear. The precise in situ folding patterns and orientations of the nephrons with respect to the other cortical elements had not been demonstrated. It also was not known whether certain nephron segments are supplied exclusively by either the arterial or the portal blood flow. In the present study, a new casting compound was developed to allow selective examination of the cortical components by light microscopy. Cortical nephrons at the surface of the kidney were serially sectioned and reconstructed in order to determine: (a) their relationships to the vasculature and collecting ducts; (b) the location and characteristics of the tubule segments; and (c) the primary and secondary folding patterns of the tubules. The anatomical findings were documented individually and then summarized in a comprehensive diagram of the superficial cortical microanatomy. In addition, an in vivo method was used to determine the extent of portal blood distribution to the nephron segments. It was demonstrated that renal portal blood suffuses all of the segments except for the loops of Henle.
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    A modified paranotal theory of insect wing origin (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 331-338 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The theory of Kukalova-Peck ('78) is examined and rejected except for the hypothesis of the partially pleural origin of wings. Data suggest that the arthropods ancestral to insects left the water, and that movable precursors of the wings, possibly exopodites, were immobilized and fused with the tergum to form part of the complex paranota. Later, during insect adaptation for flight, parts of the complex paranota were separated secondarily and became wings.
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    Development and metamorphosis of the digestive system of larval lobsters, Homarus americanus (Decapoda: Nephropidae) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 225-242 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study provides a detailed account of the development of the digestive system of larval lobsters (Homarus americanus H. Milne Edwards, 1837) and the morphological changes that occur at metamorphosis. The most dramatic of these changes involves the gastric mill of the cardiac stomach. First-and second-stage lobsters lack the medial and lateral teeth characteristic of the grinding stomach of adult lobsters. Clearly recognizable, heavily cuticularized teeth first appear in the third stage, and accessory lateral teeth do not appear until the fourth stage. In place of the teeth of the gastric mill, first- and second-stage stomachs have a series of pads and ridges which are the apparent rudiments of the teeth. The development of the gastric mill during the larval stages enables lobsters to deal successfully with the more substantial food they encounter in the benthic environment, and corresponds to the drastic change of habitat and diet which occurs at metamorphosis.Confusion about the extent of the midgut and hindgut in larval lobsters has been clarified. The results of this study have shown that the larvae have a long midgut, which lacks a cuticle, and a short hindgut with a cuticular lining, just as in adult lobsters. The junction between midgut and hindgut lies in the sixth abdominal segment in all of the first four stages, as well as in the adult.
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    Morphology of the embryonic stages of the viviparous scorpion, Heterometrus fulvipes: A photographic study (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 275-281 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The embryonic development of the viviparous scorpion, Heterometrus fulvipes, has been followed throughout the gestation period and the successive stages of the developing embryos have been examined. The morphological features of the embryos are also described and illustrated according to their approximate age.
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    Descriptive and functional anatomy of the digital vascular system of the tokay, Gekko gecko (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 293-323 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The vascular system of the digits of the tokay is more complex than has hitherto been suspected and has a configuration which suggests it is intimately involved in the process of adhesion. Distinction can be made between lamellae (expanded scales beneath the proximal portion of the digit) and scansors (elaborations of lamellae that contain a large amount of subdermal material and therefore do not technically qualify as scales). Such a distinction is made on anatomical grounds and can be appreciated only if anatomical investigation is carried out. There are no externally obvious features by which lamellae and scansors can be distinguished, except position. Scansors are found beneath hyperextensible phalanges, whereas lamellae are located more proximally and are not subjected to digital hyperextension during locomotion. Whether this distinction can be applied to other pad-bearing geckos and to anoline lizards remains to be seen.The large sinus beneath the penultimate phalanx appears to govern the pressure within the system; the reticular blood systems of the scansors appear to manifest the pressure changes with respect to the locomotor substratum. Changes in pressure within the system probably permit the overlapping scansors to comply precisely with each other and with the substratum. The presence of a system based on fluid pressure differentials means that scansors are deformable along multiple axes at any one time, thus permitting a high degree of compliance with their entire surroundings. It is probable that changes in pressure within the system promote release from the substratum as well as compliance with and attachment to it. The mechanism of control of the system awaits further investigation.The pattern of the digital vascular complex has been considered in relation to the mode of operation of the digits during locomotion. Distal drainage of the sinus is ideally suited to the activity of hyperextension of the digits. This combination permits sequential pressurizing and depressurizing of the scansors and allows the bond to be created or broken in a gradual fashion rather than in an all-or-none manner. By avoiding sudden shifts in the pattern of dynamic loading (the bond is not broken instantaneously but sequentially), the risk of transverse instability during locomotion is lessened. The increase of loading on the other feet is thus gradual. The importance of this is discussed more fully elsewhere in a consideration of the structure and function of scansors. That the digits of the tokay are hyperextended during horizontal as well as vertical locomotion (Russell, '75, p. 463) can now be rationalized not only from the point of view of protection of the setae but also because of the manner in which the vascular system of the digits functions and is drained.
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    Retinal afferents and efferents of an infrared sensitive snake, Crotalus viridis (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 29-42 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The retinal afferents and efferents were examined in Crotalus viridis. Retinofugal fibers were traced by injecting horseradish peroxidase (HRP) or tritiated leucine into the eye, or by removing the eye and staining degenerating axons with silver methods. Terminations were seen contralaterally in the suprachiasmatic nucleus, the dorsal and ventral lateral geniculate nuclei (extensive), the pretectal nuclei, including the nucleus posterodorsalis (a very heavy input), the nucleus lentiformis mesencephali, nucleus geniculatus pretectalis, and nucleus pretectalis, the superficial layers of the optic tectum, including the stratum zonale, the stratum opticum, the stratum griseum et fibrosum centrale and the upper portion of stratum griseum centrale, and the basal optic nucleus. Ipsilateral input reaches the intermediate portion of the dorsal lateral geniculate nucleus, a small portion of the pretectal nucleus and nucleus posterodorsalis, and the basal optic nucleus (very minimally). Retinopedal fibers were traced with the HRP method. The cell bodies lie in the ventral thalamus within the nucleus of the ventral supraoptic decussation. These neurons project primarily to the contralateral retina, but some more rostrally located neurons project to the ipsilateral retina.
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    Analysis of mesenchyme in the developing hind limb of Rana pipiens larvae with implications for neural development (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 253-257 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mesenchyme in the hind limbs of Rana pipiens tadpoles may serve as an important influence on the development of specific neural structures involved in limb innervation. Thus a histological quantification of mesenchyme was undertaken to identify landmark stages with respect to mesenchyme presence and neural events. Mesenchyme remained as a high percentage of the limb tissue until stage V (Taylor-Kollros stages, '46), after which it declined dramatically until its virtual absence after stage XI. The volume of mesenchyme, however, was greatest at stages VIII-IX. Periods of high and low mesenchyme content were correlated in time with potential limb involvement in regulating limb innervation and motor neuron loss from the lateral motor columns. This provides additional evidence for developmental relationships between events of the limb and neural tissues.
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    Arterial circulation of the spinal cord and brain in the monodontidae (Order cetacea) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 171-180 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this paper we document retial supply of the spinal cord and describe the arterial vascular pattern of the brain in the whale family Monodontidae. Observations are based on gross dissections of four brains, two each of Monodon monoceros and Delphinapterus leucas, and one spinal cord from M. monoceros.Vessels of the spinal cord arise from extradural retia in the neural canal. Arteries originating from the retia penetrate the dura between successive spinal roots (mainly ventral) and not in association with them, unlike radicular arteries of other mammals. Also, these vessels are uniformly distributed and contribute equally to a plexus surrounding the cord. An A. radicularis magna is not present, and neither are dìstinct anterior or posterior spinal arteries.Circulation to the brain is effected by two pairs of arteries originating from intracranial retia. The rostral pair supplies most of the forebrain (prosencephalon), whereas the more caudal pair supplies mainly the midbrain (mesencephalon) and hindbrain (rhombencephalon). The circulatory pattern is characterized by (1) complete independece of anterior cerebral arteries (no anastomoses); (2) extensive cortical supply by the anterior choroidal arteries; (3) absence of subdural communicating vessels between rostral and caudal trunks; (4) union of caudal trunks to form a small basilar artery; and (5) absence of vertebral arteries and hence of a vertebral basilar system. There are some obvious differences between subdural arteries in the Monodontidae and those in other mammals; however, their general patterns of distribution are similar, and we suggest that most of the vessels, at least in the cranium, are homologous.
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    Mandibular movement and muscle activity during mastication in the guinea pig (Cavia porcellus) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 147-169 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Optoelectronic analysis of mandibular movement and electromyography (EMG) of masticatory muscles in Cavia porcellus indicate bilateral, unilateral, and gnawing cycles. During bilateral and unilateral cycles, the mandibular tip moves forward, lateral, and down during the lingual phase of the power stroke to bring the teeth into occlusion. EMG activity is generally asymmetric, with the exception of activity of the temporalis muscle during bilateral cycles. During gnawing cycles, the mandible moves in an anteroposterior direction that is opposite that during bilateral and unilateral chew cycles. Bilateral and unilateral cycles of pellets were significantly longer than carrot. With the exception of the width of bilateral cycles, the magnitude of cycle width, length, and height during the mastication of carrots was greater than that during the mastication of pellets. Significant differences exist between EMG durations during mastication of pellets and carrots. The lateral pterygoid displays continuous activity during gnawing cycles. Significant differences also exist in the durations of EMG activity between the working and balancing side during all three cycle types. High level activity of balancing side temporalis and anterior belly of digastric (ABD) during bilateral cycles occurs during rotation and depression of the mandible during the power stroke. The temporalis apparently provides a „braking“ or compensatory role during closing and power strokes. Differences between Cavia masticatory patterns and those shown by Rattus and Mesocricetus are apparently due to differences in dental morphology, occlusal relationships, and, possibly, the poorly developed temporalis in Cavia. The large number and wide diversity of rodent groups afford students of mammalian mastication an opportunity to investigate and compare different masticatory specializations.
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    A scanning electron microscopic study of the molar surfaces of the mandibles of the brine shrimp (Cl. Branchiopoda: O. Anostraca) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 239-251 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Scanning electron microscopy was used to characterize the external morphology of the molar surface of the mandibles of the brine shrimp, Artemia salina. Unlike many other branchiopod crustaceans, Artemia has symmetrical mandibles, ie, the molar surfaces of the two mandibles of an individual are similar in size and surface structure. Each molar area has three basic regions: the anterio-ventral region, posterio-dorsal region, and transition zone. On the anterio-ventral region there are complex, parallel furrows and ridges, which are specializations for clasping masses of fine, particulate food. The general surface of this ridged area is flat, except at the ventral and anterior edges, where there is a fringe of long projections that probably serve to retain food in the space between the paired mandibles. The posterio-dorsal region, which has simpler, more sparse cuticular projections, is adapted for reception of food. Stereomicrographs reveal that the general surface of this region is sloped and thus forms a cleft along the posterio-dorsal margin of the two apposed molar surfaces. Anatomical relstionships suggest that the cleft is an adaptation for accommodating maxillular setae that push food forward onto the mandibles. The transition zone has cuticular specializations that are morphologically intermediate between those of the anterio-ventral and posterio-dorsal regions. Three types of pores, possibly openings of glands or sensilla, were observed in the cuticle of the molar surface.
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    Morphological features of sessile and circulating hemocytes in the cephalon of Gammarus setosus dementieva (Crustacea: Amphipoda) by light and electron microscopy (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 253-269 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An aggregation of sessile spherulocytes in the cephalon of female Gammarus setosus surrounds the ramifications of the dorsal aorta and the peripheral ganglion of the frontal organ nerve. It is not a hemopoietic organ. The spherulocytes are of three distinct varieties that may represent phases of a secretory cycle possibly synchronized with molting or reproduction. In addition, four other hemocyte types were identified in the cephalic blood sinuses: prohemocyte, plasmatocyte, granulocyte, and adipohemocyte. The cellular and nuclear dimensions of these hemocytes were analyzed. They were shown to be uniform in cell size with average cell area of 69.27 μm2, and average maximum cell diameter of 11.75 μm. The mean nuclear area and mean maximum nuclear diameter of the prohemocyte are significantly larger than those of the other cell types. The structure of the hemocyte types is described and compared to those of other crustaceans and insects.
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    An ultrastructural study of spermatogenesis in the nudibranch mollusc Spurilla neapolitana (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 283-299 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructural features of spermatogenesis were investigated in the nudibranch mollusc Spurilla neapolitana. Sperm develop in the proximal half of numerous sac-like acini which are radially arranged within about ten ovotestis lobes. Accessory cells line the inner wall of the testicular portion of each acinus and are connected to developing sperm by numerous desmosomes. Stages of spermatid development have been divided into precup, cup, postcup, and elogate stages depending on the general shape of the nucleus. Nuclear differentiation includes the formation of anterior and posterior nuclear plaques, condensation of chromatin fibrils into nuclear lamellae, the insertion of the developing flagellar axoneme into a shallow, nuclear implantation fossa, and eventual formation of an elongated sperm head with a terminal twist. Spermiogenesis also includes the differentiation of an anterior, perinuclear structure having the characteristics of an acrosome, the appearance of peculiar arrays of ER cisternae, and the fusion of mitochondria into a large mitochondrial derivative which eventually encircles the axoneme, forming a crystalline-like periaxonemal sheath.
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    Foot of two-toed sloths: Its anatomy and potential uses relative to size of support (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 357-372 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Feet of two-toed sloths (Choloepus) are long, narrow, hook-like appendages with only three functional digits, numbers II, III, and IV; Rays I and V are represented by metatarsals. Proximal phalanges of complete digits are little more than proximal and distal articulating surfaces. All interphalangeal joints are restricted, by interlocking surfaces, to flexion and extension. Ankle and transverse tarsal joints, however, allow extreme flexion and inversion of foot. Powerful digital flexion is augmented by several muscles from extensor compartment of leg. Intrinsic foot musculature is reduced to flexors and extensors but these, with the exception of lumbricals, are large and well developed. Choloepus uses its feet much like hooks with distal phalanges and covering claws forming the “hook” element. These hook-like appendages are seemingly best suited for supports less than 50 mm in diameter suggesting that two-toed sloths may prefer supports of this size in their natural habitat.
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    The organization and structure of nerve and muscle in the jellyfish Cyanea capillata (coelenterata; scyphozoa) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 383-399 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The perirhopalial tissue and swimming muscle of Cyanea were examined with light microscopical and electron microscopical techniques. The perirhopalial tissue is a thin, triangular septum found on the subumbrellar surface of the animal. It separates part of the gastric canal system from the surrounding seawater, and is bound on two sides by radial muscle bands and on the third, the shorter side, by a rhopalium and the margin of the bell.The ectoderm of the perirhopalial tissue is composed of large, somewhat cuboidal, vacuolated, myoepithelial cells. The muscle tails of these cells form a single layer of radial, smooth muscle. Neurons of the “giant fiber nerve net” (GFNN), which form an extensive net over the perirhopalial tissue, lie at the base of the vacuolated portion of the myoepithelial cells. These neurons are visible in living tissue. The morphology of individual GFNN neurons was examined following intracellular injection of the fluorescent dye Lucifer Yellow. The neurons are usually bipolar and free of branches. At the electron microscope level, one usually finds that the GFNN neurons contain large vacuoles. The other characteristic feature of these cells is that they form symmetrical, or nonpolarized, synapses; that is, synaptic vesicles are found on both sides of the synapse.The swimming muscle is striated and composed of myoepithelial cells. Each myoepithelial cell has several muscle tails, and those of adjacent cells are linked to gether by desmosomes. The endoderm of the perirhopalial tissue also was examined.This investigation of the organization and ultrastructure of the perirhopalial tissue and surrounding muscle was undertaken to provide essential background information for an ongoing physiological study of the GFNN neurons and their synapses.
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    Determination of temperature sensitive stages for sexual differentiation of the gonads in embryos of the turtle, Emys orbicularis (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 373-382 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In order to determine the temperature sensitive stages for sexual differentiation of the gonads in Emys orbicularis, eggs of this turtle were shifted at different stages of embryonic development from the male-producing temperature of 25°C to the female-producing temperature of 30°C and reciprocally. Based on the series of developmental stages described by Yntema (′68) for Chelydra serpentina, temperature begins to influence sexual differentiation of Emys orbicularis at stage 16, a stage in which the gonads are still histologically undifferentiated. Its action lasts over the first steps of histological differentiation of the gonads. The minimal exposure at 25°C required for male differentiation of all individuals extends from stage 16 to somewhat before stage 21. For 100% female differentiation, incubation at 30°C must be longer, from stage 16 to somewhat before stage 22. Shorter exposures at 25°C or 30°C during these periods result in different percentages of males, females, and intersexes. Our results show that there is a critical stage (stage 16) which is the same for both male and female differentiation of the gonads. The thermosensensitive periods are rather long, corresponding to 11-12 days at 25°C and 30°C.
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    Announcement (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 271-272 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051700211
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    Ultrastructure of the heart of the marine mussel, Geukensia demissa (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 301-319 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure of the heart of Geukensia demissa, a common object of physiological and biochemical investigation, is described by scanning, transmission and freeze-fracture electron microscopy. A single-cell epithelial layer covers the ventricle, but an endothelium is lacking. Myofibers are small (6-7 μm diam.), mononucleate, and tapered. Glycogen is concentrated peripherally. Mitochondria are particularly concentrated under the sarcolemma, near the ends of the nucleus, and in rows between bundles of myofilaments. The myofilaments (6-8nm thin, 30-35 nm thick filament diam.) are loosely arranged into sarcomeres (2-4 μm) by Z bodies. Many of these Z bodies interconnect, and some anchor to the sarcolemma forming attachment plaques. Cells are joined by intercalated discs consisting of fascia adherentes, spot desmosomes, and gap junctions. The gap junctions include intramembrane particles. T tubules are absent. The sarcolemma is coupled to the junctional sarcoplasmic reticulum (JSR) over 357ndash;40% of the cell surface. Tubules extend from the JSR deep into and throughout the cell as an irregularly dispersed network. The SR occupies 1% of the cell volume. A few, small (0.1-1.0 μm) unmyelinated nerves are present, but no neuromuscular junctions were seen. The auricles have fewer and smaller myocytes than the ventricle. The auricles also contain podocytes with pedicels having 20-35 nm slits and containing sieve-like projections. The morphology of the Geukensia heart is similar to that of other bivalves.
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    Erratum (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 401-401 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051700310
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    Effect of bone strain on cortical bone structure in macaques (Macaca mulatta) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 1-12 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: It has recently been shown that the consistency of food significantly affects levels of bone strain in the mandible during mastication (Hylander, '79a). Mandibular bone histology was examined to test the effects of a diet of hard food compared to a diet of soft food in two group of monkeys. One group of rhesus macaques (Macaca mulatta) was fed a diet of commercially prepared hard biscuits. The second group was fed a soft diet the consistency of fudge. Both diets were nutritionally adequate for normal growth and development. As a control for other factors influencing cortical bone structure, fibular morphology was also examined. At the end of the test period, mandibular and fibular tissue samples from the two groups were prepared to determine the amount of secondary Haversian bone present. Mandibular depth at M2 and fibular anteroposterior diameter were also measured and compared between the two dietary groups.The soft-diet monkeys showed low levels of remodeling in their mandibles. There were large patches of unremodeled bone and resorption spaces were common. The hard-diet monkeys exhibited more extensive evidence of secondary Haversian remodeling in their mandibles. The hard-diet monkeys also had deeper mandibles. In contrast, the fibulae from the two groups had similar mean diameters and showed comparable levels of secondary remodeling. We infer that the higher mandibular bone remodeling levels in the hard-diet monkeys represent an adaptive response to remove and replace fatigued mandibular bone due to higher stress levels associated with the ingestion and mastication of hard foods. We also infer that greater depth of the mandible at M2 found in the harddiet group represents an adaptive response to higher stress levels associated with the ingestion and mastication of hard foods.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051670201
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    Ultrastructure of the supporting cells in the chemoreceptor areas of the tentacles of Pomatias elegans (Müller) (mollusca, prosobranchia) and the ommatophore of Helix pomatia L. (Mollusca, Pulmonata) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 211-230 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of the supporting cells in the chemoreceptor areas of the tentacles of Pomatias elegans and Helix pomatia is very similar. Complex apical structures are present, and the lateral plasma membrane exhibits three zones: (1) a zone of slight interdigitations; (2) a zone characterized by longitudinal plicae; (3) a zone of basal radiculae. The portions of the sensory cells located within the epithelial layer are accommodated in longitudinal grooves in the supporting cells. However, there are also differences. In Pomatias elegans the apical surface is differentiated into long microvilli that are sometimes dichotomously branched and invested by a surface coat along their entire length. Cytofilia and cilia of the sensory cells pass through this layer of microvilli and surface coat throughout its entire width. In Helix pomatia the supporting cells are somewhat smaller and the apical differentiation consists of candelabra-like protrusions, which are usually three times dichotomously branched. The final branchings, corresponding to microvilli, are called terminal twigs. They are covered by a surface coat, which forms a feltwork. The cytofilia and cilia of the sensory cells that intertwine among the protrusions are confined to the space below the terminal twigs, where they compose the spongy layer.
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    Autonomic innervation of salivary glands in the armadillo, anteater, and sloth (Edentata) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 151-157 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The intraglandular distribution of adrenergic and cholinergic nerve fibers was studied histochemically in the parotid, mandibular, and sublingual glands of six species of edentates belonging to the three families that comprise the order; namely, the Dasypodidae (armadillos), the Myrmecophagidae (anteaters), and the Bradipodidae (sloths). The following histochemical techniques were used: (a) acetylcholinesterase reaction for the demonstration of cholinergic fibers; (b) formaldehyde- and glyoxylic acid-induced fluorescence for the demonstration of adrenergic fibers. In addition, norepinephrine (NE) was assayed fluorimetrically in the mandibular and parotid glands of the armadillo. A network of acetylcholinesterase-positive nerve fibers surrounds the intra- and interlobular ducts and endpieces of all glands; it is of low density in the mandibular and sublingual gland of the sloth, of high density in the sublingual gland of the anteater and of moderate density in the remaining glands. A vascular cholinergic innervation occurs in all salivary glands. Although present around the vessels, adrenergic new fibers were virtually absent from the parenchyma of all glands, even after in vitro incubation of glandular tissue with NE, or after administration of NE to armadillos previously treated with a monoamine oxidase (MAO) inhibitor. Consistent with this fact, the amount of NE present in the parotid and mandibular gland of the armadillo was extremely low. These findings may indicate that the salivary secretion in the edentates is regulated by the parasympathetic rather than by the sympathetic nervous system.
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    Structure and functional aspects of the scotopic compound eye of the sugarcane borer moth (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 73-84 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Morphology and functional aspects of the scotopic compound eye of the moth Diatraea saccharalis, studied using light and electron microscopy, is presented. An ommatidium is composed of a laminate corneal lens, four Semper cells, a refractive cone, two primary pigment cells, six screening pigment cells, a crystalline tract that functions as an optical waveguide, and six to eight sensory retinular cells. Accessory light regulators consist of screening pigment cells that, in the dark-adapted position, increase receptor sensitivity by permitting light rays to cross over to adjacent ommatidia and specialized tracheal regions that enhance sensitivity by reflecting light back toward sensory receptors.
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    Evidence for the holocrine nature of lipoid secretion by avian epidermal cells: A histochemical and fine structural study of rictus and the uropygial gland (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 167 (1981), S. 185-199 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cells of the avian epidermis (rictus of the chicken), when examined under the light microscope following suitable fat staining, show similarities to epithelial cells of the uropygial gland of chicken and pigeon, an organ which is recognized both morphologically and functionally as a holocrine gland. Evidence thus far from electron microscopic studies strongly suggests that the skin of the bird is also a holocrine gland, although details of cytogenesis and secretion differ somewhat in the two organs.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051690201
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    Primary palatal development in the chick (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 185-190 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Seventy-nine chick embryos were examined by light microscopy and scanning electron microscopy to determine the mechanism of primary palatal development. Fusion between two discrete processes, the medial nasal and maxillary prominences, was found to be necessary for formation of a complete primary palate. This was one component of a three-stage process that included: (1) invagination of the nasal pit prior to the appearance of the facial prominences; (2) fusion between the medial nasal and inaxillary processes caudal to the nasal groove; (3) rupture of the bucconasal membrane. The lateral nasal and maxillary prominences were found to be part of the same tissue mass. Mergence was proposed as a mechanism for the obliteration of the groove between these two localized prominences. These results were compared with those obtained by other authors for primary palate formation in rodents and man.
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    The digging behavior and skin differentiations in Heterocephalus glaber (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 51-71 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The topography and histology of the skin of the naked mole (Heterocephalus glaber) have been correlated with its behavior. The integument is exceptionally loose, thereby reducing integumentary stresses when the animal is digging and moving in narrow tunnels. It also allows the position of the nasolabial sensory patch to change. This patch is exposed to mechanical stimuli when Heterocephalus moves along the tunnel, but becomes partially shielded by a transient buccal evagination, the formation and function of which are here described. Most of the differentiated patches of the skin lie in the cranial and anogenital regions. The eyes are microphthalmic and nearly completely closed by the nonmobile eyelids; there is no pinna, hair-coat or sweat glands.The epidermis is of variable thickness; in some places it has only one layer of cells. The detached epidermal cells penetrate the dermis irregularly.The epidermis of Heterocephalus is specialized by modifications of its germinative stratum, equivalent to an epidermosis, the syndrome of which consists of reduction of all types of epidermal buddings - pilogenetic and adenogenetic - as well as those which have a mechanical significance.
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    The cardiac ventricles of a baleen whale (Balaenoptera acutorostrata: Minke whale) and a toothed whale (Hyperoodon ampullatus: Bottlenose whale) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 85-96 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fifteen minke whale (Balaenoptera acutorostrata: Mysticeti) and three bottlenose whale (Hyperoodon ampullatus: Odontoceti) hearts were obtained from Norway. Only the ventricular mass and the base of the great arteries were available for study. The shape of the heart, the double apex, the narrowness of the interventricular septum in the dorsiventral plane, the side-to-side position of the ventricles, the relative thickness of the wall of the right ventricle, and the heavy trabeculation agree with other, brief reports of whale heart morphology. Coronary artery tortuosity, which has been described in sperm whales by others, was found in the bottlenose but not in the minke whales. It is suggested that the shape of the heart is associated with depth and duration of dives and that the pattern of trabeculation may be related to the size of the animal.
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    An ultrastructural and fluorescence histochemical investigation of the innervation of retial arteries in Monodon monoceros (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 109-119 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this study, the innervation of cerebrally related retial arteries in the narwhal Monodon monoceros was examined. Vessels were processed for the demonstration of adrenergic nerve endings by fluorescence histochemistry, and the results were confirmed by electron microscopy. Innervation of cerebrally related retial arteries was compared to that of a system situated in the haemal canal and supplying the tail. The retial arteries were poorly innervated. Adrenergic nerve endings, as indicated by fluorescence, occurred only in caudal portions of the spinal rete. Ultrastructurally, nerves were found in most retial vessels examined. However, except for arteries from caudal portions of the spinal rete, nerve numbers were few and because they occurred in outer layers of the adventitia were probably not functionally significant. In contrast, vessels in the haemal canal were well innervated. Nerve endings possessing neurotransmitter vesicles were adjacent to the smooth muscle cells. The cetacean rete mirabile, a system which supplies blood to the entire central nervous system, is apparently not under extensive nervous control, even though most reports suggest there is a relationship, possibly based on the presence of adjacent nerve trunks. Any vasomotor activity that does occur, possibly does so in response to catecholamines or other vasoactive agents circulating in the blood.
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    Ultrastructure of the wax-gland system in subterranean scale insects (homoptera, coccoidea, margarodidae) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 159-170 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of wax glands (integumentary, stigmatic, and peristigmatic glands) was investigated in larvae, cysts, and adult females and males of species belonging to the genera Porphyrophora, Sphaeraspis, and Eurhizococcus. The general organization and cytological characteristics are similar for all glands studied. Each gland is composed of a single layer of 8 to 40 cells. The glandular cells are characterized by a very large quantity of smooth endoplasmic reticulum which forms dense zones throughout the cytoplasm, but is always placed near the collecting canals in the presence of mitochondria. Each cell has a central canal reservoir which penetrates it deeply and gives rise to a large number of lateral collecting canals, formed by the invagination of the apical plasma membrane. The canals open into a subcuticular cavity forming a common reservoir in which the secretion is accumulated. This reservoir is covered by a modified cuticle formed from the endocuticle and the epicuticle. The endocuticle is composed of a network of fine tubular structures and has many filaments on its surface. The epicuticle is perforated by numerous pores. There is no cuticular duct. The secretion crosses the cuticle in three successive steps. First, it passes through the filaments, then through fine tubular structures of the endocuticle, and finally through the epicuticular pores.
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    Early ultrastructural changes of developing oocytes in the dog (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 171-179 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Many aspects of the developmental stages of the oocyte of the dog resemble those of other mammalian species. The oocyte of the dog, however, contains large amounts of lipid yolk material. A study of the ultrastructural morphology of early growth and maturation of dog oocytes was undertaken to clarify the nature and appearance of this yolk material. The lipid yolk first appears in early primary oocytes as aggregated dense bodies that gradually fill the ooplasm as the oocyte matures. The site of the yolk's initial appearance is consistently related to a single centriole and often to the lamellae of smooth endoplasmic reticulum that surrounds groups of forming lipid yolk bodies. Dense cortical granule-like vesicles are found to lie deep within the maturing oocyte and often are enclosed within the lamellar yolk space. Granules within this space undergo changes in size, matrix configuration, and vacuolization. These changes suggest a mechanism whereby material is added to the lipid yolk bodies. Light microscope histochemistry for lipid and polysaccharide material is described.
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    Sensilla of the antennae and the labial and maxillary palps of Blattella germanica (L.) (Dictyoptera: Blattellidae): Their classification and distributionPaper of the journal series, New Jersey Agricultural Experiment Station, Cook College, Rutgers Univ., New Brunswick, New Jersey. (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 269-279 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The various sensilla on the antennae and on the labial and maxillary palps of Blattella germanica (L.) were studied. Thick-walled chemoreceptors with fluted shafts and articulated bases are located on the antennae and on the labial and maxillary palps. Thin-walled chemoreceptors, without fluted shafts or articulated bases, are restricted to the flagellar segments of the antennae and to the distal segments of the palps. Antennae of adult males have more thin-walled chemoreceptors than do those of females. Hair-plate sensilla are found at the scape-head and scape-pedicel joints, and at the joints of segments on the palps. Campaniform sensilla are concentrated as a ring around the distal margin of the pedicel, and are also scattered singly on the scape, pedicel, and flagellar segments of the antennae, and on the first segment of the maxillary palps. Occasionally, a few sensilla coeloconica and cold receptor sensilla are found on the antennal flagellum.
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    URL: http://dx.doi.org/10.1002/jmor.1051680303
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    A three dimensional serial reconstruction of neuronal distributions in the hypostome of a Hydra (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 168 (1981), S. 321-329 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The numbers, types, and distributions of neurons in a hypostome of Hydra littoralis were determined from electron micrographs of serial (0.25 μm thick) sections. In 1,080 serial sections examined we found 75 sensory cells and 949 centrally located ganglion cells. More than 96% of the 1,024 neurons identified had a single cilium.Sensory cells were most numerous near the apex of the hypostome. Proceeding away from the apex, they steadily decreased in numbers; at 120 μm they were no longer observed. Ganglion cells were bimodally distributed; some were associated with sensory cells at the apex, but most were found at the sites of tentacle origin.We observed, throughout the hypostome, a total of 64 neuronal clusters (three or more contiguous neurons), with an average of five and a maximum of 11 neurons in a cluster. Clusters were distributed similarly to ganglion cells: an initial concentration of clusters near the apex; the majority at the hypostometentacle junctions.Each neuron identified was traced through succeeding sections in which it was observed. We used a three coordinate system to create a three-dimensional reconstruction of the neuronal locations in the hypostome. Although the functional significance of the neuronal distributions we observed is unknown, we suggest that neurons at the apex of the hypostome transduce sensory information involved in feeding behavior. The neuronal concentrations at sites of tentacle origin may be responsible for initiating Contraction Burst Pulses associated with rhythmic behavioral patterns of Hydra or coordinating tentacle movements involved in prey capture, ingestion or locomotion.
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    URL: http://dx.doi.org/10.1002/jmor.1051680308
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    The serotonergic somatosensory projection to the tectum of normal and eyeless salamanders (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 55-69 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The spinotectal somatosensory projection was compared in normal, genetically eyeless, and embryonically manipulated salamanders. In normal animals, serotonin fluorescence was restricted to the intermediate tectalneuropil. This same region showed both high levels of serotonin uptake and somatosensory single unit electrical activity. In mutant eyeless salamanders and in normal animals enucleated early in development, serotonin fluorescence, serotonin uptake, and somatosensory activity were present in the superficial tectal neuropil. One-eyed animals, either genetically normal axolotls with one eye enucleated embryonically or genetically eyeless animals in which a normal eye had been transplanted, showed normal intermediate serotonin fluroescence and somatosensory physiology in the visually innervated half-tectum. In the visually uninnervated half-tectum, they showed superficial serotonin fluorescence and somatosensory physiology.In normal animals, 5,7-dihydroxytryptamine (5,7-DHT), a specific poison for serotonergic fibers, eliminated physiological responses in the contralateral somatosensory tectal region. The 5,7-DHT poisoning also abolished U.V.-induced serotonin fluorescence in the intermediate tectal neuropil.These results are discussed in terms of (1) evidence for serotonin as a central neurotransmitter for somatosensory information in the tectum, (2) the effects of eyelessness on tectal organization, and (3) related results in other animals.
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    Vascular architecture and intestinal hematopoietic nests of two cyclostomes, Eptatretus burgeri and ammocoetes of Entosphenus reissneri: A comparative morphological study (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 71-93 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Vascular architecture and the structure of the intestinal hematopoietic centers of two cyclostomes, the hagfish Eptatretus burgeri and the ammocoetes larva of Entosphenus reissneri, are compared. Blood cells of the hagfish are generated in hematopoietic nests that develop around intestinal veins established primarily for transport of absorbed nutrients. In ammocoetes, on the other hand, blood cells are generated in hematopoietic nests of the typhlosole, closely associated with venous sinusoids developing around the longitudinally oriented mesenteric artery of the typhlosole. A collateral vein of the mesenteric artery is completed in the typhlosole after metamorphosis. Since the spleen of higher vertebrates develops in relation to establishment of the collateral vein of the largest foregut artery, the intestinal hematopoietic nests of ammocoetes may be regarded as a model of the primitive form of the spleen of higher vertebrates. Hematopoiesis in the hagfish intestine is not related to establishment of a collateral vein; hence „primitive spleen“ or „intestinal spleen“ may be improper terms in reference to the intestinal hematopoietic tissue of the hagfish.Morphological characteristics of the hematopoietic nests of the two cyclostomes are essentially the same. Blood cells of these nests are generated in the intervenous tissue, supported by interstitial connective tissue cells and reticulin fibers. Granulated cells are the most common type in the primitive hematopoietic nests. No definitive erythrothrombocytopoiesis has been identified. Lymphocytes have not been observed in the hagfish; however, small lymphocytes have been observed in the vascular lumen of sinusoids around the hematopoietic nests of ammocoetes. These lymphocytes probably originate outside of the typhlosole.
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    The internal carotid artery does not directly supply the brain in the monodontidae (Order cetacea) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 207-214 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this paper we describe the gross and microscopic anatomy of the internal carotid artery and demonstrate that this vessel does not directly supply blood to the brain, in the Monodontidae (order Cetacea). Our account is based on gross dissections and perfusion casts of the arterial vasculature in Delphinapterus leucas and Monodon monoceros and on histological material from the latter species.The internal carotid artery originates low in the neck and extends to the carotid rete at the base of the brain. The vessel tapers dramatically along its cervical course and changes from an artery elastic in nature to one more muscular. A single large cervical branch occurs in D. leucas and supplies cerebrally related retia in this region and prevertebral muscles. No cervical branches occur in M. monoceros. In otic regions, the internal carotid artery is small and muscular. A lumen is present; however, a split internal and external elastic lamella and a thickened subendothelial layer are evident. Though patent in the neck and ear, the vessel appears occluded within the carotid canal. At this level, the vessel is characterized by absence of a lumen and by fragmented elastic lamellae.We conclude that the internal carotid artery is anatomically closed at a level just proximal to the carotid rete and hence has no direct involvement with cerebral blood supply in the Monodontidae. Our results confirm other investigators' work on smaller cetacean species.
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    URL: http://dx.doi.org/10.1002/jmor.1051700207
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    Fiber type composition and postmetamorphic growth of anuran hindlimb muscles (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 321-345 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fiber type composition distinguished by the level of succinic dehydrogenase, mean fiber diameter, and fiber number were determined for the gracilis major and sartorius in ontogenetic series of the anurans Rana pipiens, Bufo americanus, and Xenopus laevis to characterize muscle composition and mode of muscle growth.A correlation can be made between the respective locomotor mode of these anurans, their activity physiology, and the fiber type composition of the propulsive muscles. R. pipiens and X. laevis have hindlimb muscles composed primarily of fast-twitch, fast-fatiguing type 1 fibers. B. americanus's muscles are composed of slow-twitch, slow-fatiguing type 2 and type 3 fibers. Fiber typing is apparently useful in explaining interspecific anuran locomotor capability previously difficult to correlate with body shape. Fiber typing also affords an explantion for reported variations in metabolism during strenuous activity.Postmetamorphically, anuran muscles grow by a combination of hyperplasia and hypertrophy, but the percent fiber type composition remains unchanged. In R. pipiens and X. laevis, the muscles grow primarily by hypertrophy with the addition of relatively fewer fibers. The converse is true for B. americanus. In all three species the combinations result in strong positive allometric increases in muscle cross section. Anuran muscle growth is similar to that reported for fish and different from that associated with mammals.
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    URL: http://dx.doi.org/10.1002/jmor.1051700305
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    Quantitative analysis of intramembranous particles in the membranous system of rat liver cells at different stages of development and aging (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 133-146 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The density of intramembranous protein particles was studied by freeze-fracture. Particle density on the fracture faces of the plasmalemma and the rough endoplasmic reticulum (RER), as well as the outer and inner membranes of the nucleus and the mitochondria in rat hepatocytes were quantified. Comparison among different age groups sampled days postcoitum (dpc), days postpartum (dpp), and months postpartum (mpp) shows age-related changes in particle density in each membrane system. With the exception of the RER, particle densities increased after the 16th dpc, reached a maximum at birth, and then decreased with increasing age. Simultaneously, the number nuclear pores shows a positive correlation with the particle density of the nuclear membranes. The particle density on the membranes of the RER shows a maximum on the 16th dpc, and on the 6th dpp. Thereafter, the density of the RER decreases slightly. In all membrane systems, the density of the particles on the external fracture faces is more variable than the density of the particles on the protoplasmic fracture faces.
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    Morphological and ultrastructural aspects of Branchiobdella pentodonta Whit. (Annelida, oligochaeta) suckers (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 195-205 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The muscular system in the posterior sucker of Branchiobdella pentodonta Whit. has circular, longitudinal and radial fibers. In the anterior sucker, which has circular and longitudinal fibers, the muscle system is scarce. Concentric fibers are found around the mouth. In both suckers the glandular elements form voluminous complexes secreting mucus for attachment to the substrate. Suckers show neuromuscular junctions and three distinct types of neuroglandular junctions: one with typical neurosecretory granules, one with larger neurosecretory granules produced by cells located at the origin of the segmental nerves, and one with presynaptic vesicles. The second type is peculiar to the posterior sucker. A comparison is made between suckers of Branchiobdella and those of leeches.
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    Interdigital webbing and skin morphology in the neotropical salamander genus Bolitoglossa (amphibia; plethodontidae) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 273-282 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Arboreal salamanders of the Neotropical genus Bolitoglossa are characterized by palmate, fully webbed feet. The feet act as adhesive structures enabling the salamanders to cling to smooth surfaces. Scanning electron microscopy of skin epithelium and light microscopy of serial sections show exceptionally smooth cell surfaces and increased numbers of mucous glands on the soles of the feet. These features enhance the abilities of the feet to adhere by means of surface tension and suction. They are part of a set of morphological characteristics that may have been produced as a result of paedomorphosis.
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    Localization of crustacean hyperglycemic hormone (CHH) in the X-Organ sinus gland complex in the eyestalk of the crayfish, Astacus leptodactylus (Nordmann, 1842) (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 347-355 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The eyestalk of Astacus leptodactylus is investigated immunocytochemically by light, fluorescence, and electron microscopy, using an antiserum raised against purified crustacean hyperglycemic hormone (CHH). CHH can be visualized in a group of neurosecretory perikarya on the medualla terminalis (medulla terminalis ganglionic X-organ: MTGX), in fibers forming part of the MTGX-sinus gland tractus, and in a considerable part of the axon terminals composing the sinus gland. Immunocytochemical combined with ultrastructural investigations led to the identification of the CHH-producing cells and the CHH-containing neurosecretory granule type.
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    A crustacean statocyst with only three hairs: Light and scanning electron microscopy (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 21-28 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Standard histological and SEM techniques have been used to examine the pair of statocyst organs located in the telson of the isopod, Cyathara polita. Each organ is formed as an invagination of the dorsal cuticle of the telson. The invagination narrows to form a stalk between the statocyst and dorsal surface. A canal courses longitudinally through this stalk and forms a continuous channel between the lumen of the cyst and the external environment. On the luminal floor of each statocyst, there are three pits; each correlates with a nodule protruding from the ventro-medial wall. From each pit, a single, bifurcating hair projects dorsally to contact the single concretion within the statocyst lumen. No other static organs have been found in this animal. Thus, maintenance of equilibrium in this species appears to be under the control of but six hairs, three in each statocyst. Innervation of each statocyst is provided by a branch of a nerve which connects anteriorly with the last abdominal ganglion.
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    Parthenogenetic reproduction in lizards: Histological evidence (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 170 (1981), S. 215-237 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Hermaphroditism and sex reversal have not previously been ruled out adequately as possible explanations for the existence of unisexual species of reptiles. Therefore, we examined serial histological sections of the complete urogenital systems of nine F2 specimens belonging to two ontogenetic series of Cnemidophorus exsanguis raised in captivity in isolation from males, as well as the urogenital system of the F1 mother of one of these series. No evidence of spermatozoa or testicular tissue was found in any specimen. Comparative material reveals that the histology of the urogenital tract, including the mesonephric kidney in adults, is similar to that of females of bisexual species of Cnemidophorus. We conclude that C. exsanguis is a unisexual, parthenogenetic species whose normal reproduction does not involve sex reversal, self-fertilization, gynogenesis, hybridogenesis, or spermatozoa in any way whatsoever.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010201
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    Distribution of tubulin and actin in neurites and growth cones of differentiating nerve cells (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 167-178 
    Details
    ISSN: 0886-1544
    Keywords: nerve growth ; actin ; tubulin ; antibodies ; immunofluorescence ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Embryonic chick nerve cells, from dissociated dorsal root ganglia, were cultured on polylysine substrata and examined for tubulin and actin distribution by indirect immunofluorescence.Antibodies generated against chick brain tubulin produced specific fluorescence in growth cones, neurites, and cell bodies without revealing distribution differences or substructure in the nerve cells. However, at reduced antitubulin concentrations, differences were resolved. Tubulin fluorescence remained uniform and intense in neurites and cell bodies, but exhibited reduced intensity and patterning in growth cones. Nonneuronal cells in the reduced intensity and patterning in growth cones. Nonneuronal cells in the cultures served as controls for typical cytoplasmic tubulin fluorescence distribution. Straining controls demonstrated that fluorescence resulted from tubulin-antitubulin binding.Analogous studies, using antibodies generated against chick brain actin, demonstrated distribution differences at reduced antiactin concentrations, including “hot spots” of intense fluorescence in growth cones and a paucity of fluorescence in neurites.
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    Calcium-induced change in form of demembranated sea urchin sperm flagella immobilized by vanadate (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 349-362 
    Details
    ISSN: 0886-1544
    Keywords: Ca2+ ; flagella ; symmetry ; vanadate ; spermatozoa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Increased Ca2+ concentration causes a reversible increase in asymmetry of the flagellar bending waves of “potentially symmetric” demembranated sea urchin spermatozoa. When these flagella are immobilized with 5 μM vanadate, increased Ca2+ concentration causes a reversible increase in the total bend angle between the tip and the base of the immobilized flagella. These effects of Ca2+, and the movement which can be activated by CaATP2-, can be inhibited by vanadate, but in both cases, high concentrations of vanadate, of the order of 100 μM, are required. These observations suggest that ATP, possibly in the form of CaATP2-, is required for the Ca2+-induced change in shape of the flagella, but other observations suggest that the magnitudes of asymmetry and total bend angle are more closely related to Ca2+ concentration than to CaATP2- concentration.
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    Effects of Triton-extraction conditions on beat symmetry of sea urchin sperm flagella (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 363-370 
    Details
    ISSN: 0886-1544
    Keywords: Ca2+ ; Mg2+ ; symmetry ; flagella ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Potentially asymmetric spermatozoa are obtained when spermatozoa are demembranated in the presence of a low Ca2+/Mg2+ ion concentration ratio. They swim with asymmetric bending waves even when reactivated at low Ca2+ concentrations, and become more asymmetric when Ca2+ is increased. Potentially symmetric spermatozoa, which swim with symmetric bending waves at low Ca2+ and become asymmetric as the Ca2+ is increased, can be obtained by exposing the flagella to a high Ca2+/Mg2+ ratio, either during or subsequent to demembranation. The rate of this conversion is an increasing function of temperature and Triton concentration. Potentially symmetric spermatozoa can be reconverted to potential asymmetry, if the exposure to high Ca2+/Mg2+ is brief, and is terminated by addition of EGTA and Mg2+ before diluting the spermatozoa. The conversion to potential symmetry may involve removal of a labile component from the axoneme.
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    Masthead (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010401
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    Intercellular bridges in the embryo of the atlantic squid, loligo pealei. II: Formation of the bridge (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 455-468 
    Details
    ISSN: 0886-1544
    Keywords: intercellular bridge ; intercellular communication ; cytokinesis ; squid ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Incomplete cytokinesis followed by the disappearance of the midbody and spindle remnant results in intercellular bridges between the cells of the blastoderm of the squid embryo. An electron microscope study of the morphology of the stages of development of the intercellular bridge is presented. Cytokinesis ceased as the furrow base reached a diameter slightly larger than the midbody. As furrowing stopped, a dense material accumulated to form a cylindrical sheath 50 nm thick, lining the inner surface of the furrow base. Proteolytic enzymes showed this material to have a significant protein component. As the midbody broke down, vesicles lined the inner surface of the bridge sheath. In this configuration, there was cyto-plasmic continuity between the cells, and organelles appeared to pass through the bridge.The intercellular bridge could become temporarily closed. Vesicles entered the channel and fused with the vesicles lining the inner surface of the sheath. The vesicles enlarged until the channel became occluded with a series of transverse cisternae, the edges of which were embedded in the material of the sheath. When the bridge reopened, the transverse cisterna appeared to dissociate from the sheath, move out of the channel, and break down. Occasionally bridges were seen in which the bridge wall appeared distorted into lobes. It is suggested that such bridges might be in the porcess of breaking down, resulting in the final separation of the cells.
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    Dynein binding to microtubules containing microtubule-associated proteins (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 499-515 
    Details
    ISSN: 0886-1544
    Keywords: dynein ; tubulin ; axonemes ; microtubules ; microtubule-associated proteins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Microtubule-associated proteins (MAPs), isolated from brain tubulin, bound to and saturated outer fibers of Chlamydomonas flagella. MAPs present on these microtubules prevented the subsequent recombination of dynein. MAPs also bound to intact axonemes and thus did not specifically bind to the dynein binding sites on the A subfiber. A molar ratio of 1 mole MAP2 per 27 moles tubulin dimers at saturation of the outer fibers with MAP2 suggested that MAPs could effectively interfere with dynein recombination only if the MAPs were near the dynein binding sites to sterically prevent binding. However, electron microscopic observations indicated that MAPs were not localized but, instead, were dispersed around the outer fibers. In addition, MAP2 present at saturating amounts on in vitro assembled brain microtubules had no significant effect on dynein binding. Dynein-decorated microtubules contained clusters of arms suggesting that there may be cooperative interaction between the arms during dynein binding. Because the A subfiber of axonemes contains sites to which dynein preferentially attaches, MAPs may prevent recombination by interfering with cooperative binding to these specific sites. Dynein presumably binds with equal affinity to any protofilament on in vitro assembled microtubules, and, therefore, the MAPs may not be capable of effectively interfering with cooperative binding of dynein to these microtubules.
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    Invited review: The role of nucleotide triphosphate in actin and tubulin assembly and function (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 485-497 
    Details
    ISSN: 0886-1544
    Keywords: actin ; tubulin ; nucleotides ; polymerization ; microfilaments ; microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Both actin and tubulin, the major proteins of the cytoskeleton, bind nucleotide triphosphate (NTP) and exhibit the phenomenon of “polymerization-coupled” NTP hydrolysis. In this report I review the nature of polymerization-coupled NTP hydrolysis, and its possible role in the cellular function of actin and tubulin. Polymerization-coupled hydrolysis may be viewed as simply reflecting differences in the NTPase activity of free subunit as compared to polymer. Making assumptions concerning the values of various rate constants, it is possible to write expressions for the effects of NTP hydrolysis on the kinetics of polymerization. The role of NTP hydrolysis may be viewed in at least three different ways: (1) Hydrolysis alters the kinetics of assembly and disassembly. This leads to a consideration of the role of subunit flow in microtubule and microfilament function. (2) Hydrolysis is an essentially irreversible step that separates the assembly and disassembly reactions. This suggests a role of NTP in the regulation of polymer content during cellular cycles of assembly and disassembly. (3) NTP may allow transient stabilization of intersubunit bonds. This suggests a role of NTP in nucleation and possible regulation of nonequilibrium states of assembly.
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    Ultrastructural studies of a polygonal myofilament network in cultured rat aortic smooth muscle cells (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 193-203 
    Details
    ISSN: 0886-1544
    Keywords: polygonal network ; rat aortic smooth muscle cell ; cell culture ; electron microscopy ; amino acid analysis ; elastin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cultured rat aortic smooth muscle cells (SMC) were examined by electron microscopy and found to contain polygonal networks of 75 A° thin myofilament bundles. The cells also had large bundles of longitudinally aligned thin myofilaments with periodically spaced dense bodies. Abundant plasmalemmal vesicles were present at the cell periphery, and the cells were connected by desmosomes. Intercellular spaces contained sparse amounts of elastic fibers, a material generally present in SMC cultures. Analyses of amino acids by automated column-chromatography showed that isodesmosine and desmosine, two amino acid residues unique for elastin, were present. Accordingly, it was concluded that polygonal networks, previously detected solely in cultured nonmuscle cells, were present in SMC.Other findings suggest (1) a change in myofilament arrangement takes place during cell migration, and (2) rat aortic SMC grown in tissue culture flasks is an important experimental tool in the study of cell motility since such myofilament rearrangements were observed to occur up to fourteen days in first passage.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970010204
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    The incorporation of actin and fascin into the cytoskeleton of filopodial sea urchin coelomocytes (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 179-192 
    Details
    ISSN: 0886-1544
    Keywords: actin ; echinoderm ; fascin ; filopodia ; actin cross-linking protein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Echinoderm coelomocytes transform from petaloid cells with large motile lamellipodia to filopodial forms. During this morphological transformation, actin filaments extensively reorganize from a random meshwork into tight bundles, which become the skeletons or cores of the filopodia. Antibody localization procedures show that fascin, a 58,000 dalton actin cross-linking protein, becomes incorporated into the filament bundles as they form. Isolated filopodial cores have a pronounced transverse striping pattern, which has been previously identified with fascin crosslinks, and gel electrophoresis identifies a protein in the cores that co-migrates with purified egg fascin. A few of the core fragments also have a distinctive “cap,” which we presume is the membrane insertion site for actin filaments.We have developed a radioimmunoassay for fascin and have used it to study the redistribution of this protein during transformation. Data from the assay indicate that fascin constitutes about 5% of the total cell protein and that substantially more fascin, approximately 1.5-2 times more, is found in the Triton-insoluble cytoskeletons of the filopodial cells than in the petaloid cells. Actin, measured by the DNAase I inhibition assay accounts for approximately 10% of the total cell protein. Approximately 65% of this actin is in a soluble non-filamentous form in the petaloid cells. Our results show that actin polymerization must occur during the cell shape change, since we find approximately 25% more actin in the filopodial cytoskeleton than in the petaloid cytoskeleton. The results show a preferential incorporation of fascin into the cytoskeleton as the cells form filopodia.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010203
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  • 98
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    Motion of polymorphonuclear leukocytes: Theory of receptor redistribution and the frictional force on a moving cell (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 205-235 
    Details
    ISSN: 0886-1544
    Keywords: capping of receptors ; cell locomotion ; cell-surface interactions ; frictional force ; membrane flow ; polymorphonuclear leukocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: As a cell moves over a surface, the distribution of membrane proteins that adhere to the surface will be changed relative to the distribution of these molecules on a static cell. Observations of this redistribution offer, in principle, evidence as to the mechanisms of membrane dynamics during cell locomotion. Toward extracting such information we present and analyze a mathematical model of receptor transport in the membrane by diffusion and convection, as affected by the making and breaking of the bonds between the receptors and the surface as the cell moves.We show that the disruption of receptor-surface bonds at the tail of the cell provides a mechanism by which the frictional force opposing a cell's motion is exerted, and calculate the magnitude of this force as a function of cell velocity. Assuming this to be the major contribution to the frictional force, we show that when the shear force on a cell is above a critical value it is no longer possible for the cell to slide across the surface. For such large forces, it is still possible for the cell to roll; alternatively the cell can be torn free of the surface.Our analysis of existing data on movement of polymorphonuclear leukocytes indicates that cell motion is not accompanied by a bulk flow of membrane from the front to the back of the cell. The data also indicate that cells do not tend to roll as they move over a surface under normal conditions. The data are most consistent with a model where the membrane as a whole is stationary but where receptors that bind to the surface become coupled to sub-membrane contractile proteins.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010205
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    Meeting report. American society for cell biology (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 269-272 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010209
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  • 100
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    Chemotaxis in Tetrahymena thermophila (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 261-268 
    Details
    ISSN: 0886-1544
    Keywords: Tetrahymena ; chemotaxis ; temporal-gradient sensing ; modulation of turning frequency ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The motility pattern of Tetrahymena thermophila in a homogeneous attractant field consists of successive “runs” and “turns.” The turning frequency decreases or increases upon an abrupt increase in attractant or repellent concentration, respectively. The dose-response curve for leucine and methionine yields a saturation curve with half maximum modulation of the turning frequency at a concentration of 15 μM and 2 μM, respectively. The turning frequency is modulated at a threshold concentration of 0.02 μM and 0.50 μM for leucine and methionine, respectively. The decrease (increase) in turning frequency in the presence of an attractant (repellent) jump reverts to prestimulus frequency in a time proportional to the concentration jump. Hence, Tetrahymena seem to employ temporal-gradient sensing for chemotaxis. Spatial-gradient taxis is thus exerted by random walk, which is biased in the direction of the gradient.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010208
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