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  • General Chemistry  (13,773)
  • SPACE RADIATION  (3,357)
  • Cell & Developmental Biology  (3,100)
  • 1975-1979  (6,493)
  • 1970-1974  (7,672)
  • 1960-1964  (6,065)
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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 153-162 
    ISSN: 0148-7280
    Keywords: spermatozoa ; cell surface ; epididymis ; surface labeling ; gel electrophoresis ; proteins ; membrane ; spermatozoa ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Differences in the exposure of spermatozoa surface components during epididymal passage have been examined using lactoperoxidase-catalyzed 125I-iodination or labeling with 125I-diazodiiodosulfanilic acid. Labeled surface proteins obtained from caput and cauda epididymides were solubilized in detergent, separated by sodium dodecylsulfate polyacrylamide slab gel electrophoresis, and identified by radiography. Densitometer scans of autoradiograms revealed increased amounts or exposures of surface proteins of ∼35,000, ∼39,000, ∼50,000, and ∼78,000 molecular weight on the cauda epididymal spermatozoa.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 177-185 
    ISSN: 0148-7280
    Keywords: multiple enzyme forms ; acid nitrophenyl phosphatase ; sea urchin ; development ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Acid nitrophenyl phosphatases from sea urchin eggs and embryos were investigated by gel filtration. Four different forms were found in Hemicentrotus pulcherrimus, and three forms in Anthocidaris crassispina and Pseudocentrotus depressus.The first and second forms (designated AcP-1 and AcP-2) had the highest activity in the range of pH 5.6-6.0. The third (designated AcP-3) had an apparent optimum pH between pH 4.3 and 4.8, and the fourth (designated AcP-4) showed the maximum activity at pH 3.0. AcP-1 was much more thermolabile than AcP-2 and AcP-3 at 56°C. NaF inhibited AcP-2, AcP-3, and AcP-4 but not AcP-1. AcP-1, AcP-2, and AcP-3 were observed in the three species, whereas AcP-4 was not detected in A. crassispina and P. depressus. AcP-1, AcP-2, and AcP-3 were separted by gel filtration.AcP-1 and AcP-2 of A. crassispina and H. pulcherrimus were studied in developing embryos. The behavior of these forms in gel filtration changed during development, from unfertilized eggs to the pluteus stage.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 187-192 
    ISSN: 0148-7280
    Keywords: zona isolation ; collagenase ; receptor for sperm ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Zonae pellucidae were collected from bovine ovaries by chopping, dispersing the chopped tissue with collagenase, sieving through nylon mesh screens, and pipetting. The zonae were free of corona cell processes when examined under the scanning electron microscope. Solutions of zonae obtained with collagenase exhibited the same antigenic and sperm receptor properties as those obtained without enzyme treatment.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 207-211 
    ISSN: 0148-7280
    Keywords: sperm ; capacitation ; acrosome ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Suspensions of nearly 100% viable golden hamster sperm were prepared by passing washed cauda epididymal sperm through a column of 0.25-0.3 mm glass beads. Incubations of these viable sperm under in vitro capacitation conditions in volumes of 0.1 or 1 ml (2-2.5 × 106/ml) resulted in 85-92% viable sperm after four hours and 45 minutes of incubation. More than 70% of these sperm were judged to have been capacitated after four hours and 45 minutes of incubation on the basis of their having undergone acrosome reactions and the presence of high numbers of sperm exhibiting the activated motility characteristic of capacitated hamster sperm.Thus, for the first time, procedures are available that will yield large numbers of viable capacitated sperm for biochemical analysis and that will also allow other studies of hamster sperm capacitation with minimum interference from molecules released from dead sperm.
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  • 5
    ISSN: 0148-7280
    Keywords: speramtozoon-copepoda (My tilicola intestinalis) ; external morphology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The external structure of the male gamete of Mytilicola intestinalis is studied under a scanning electron microscope and compared with transmission electron micrographs of thin sections corresponding to the different parts of same. The cell in question is long and filiform, showing, along a significant part of its length, two ridges or expansions helicoidally arranged and diametrically opposed. Four different parts or segments can be identified in this spermatozoon: segment A, characterized by its screw-like aspect; segment B, the longest, provided with well-developed helicoidal expansions; segment C, showing an uneven surface and lacking expansions; and segment D, with a smooth surface and decreasing diameter. The significance of this original structure in a spermatozoon, considered immobile until now, is discussed, stating different hypotheses with regard to the possible mobility of the cell just before fertilization takes place.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 283-293 
    ISSN: 0148-7280
    Keywords: in vitro fertilization ; mouse ; second polar body formation ; second meiotic division ; spindle ; polarizing microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The second meiotic division and polar body formation in mouse eggs fertilized in vitro were observed by phase-contrast and polarizing microscopy, and recorded by time-lapse cinematography. Eggs were collected from oviducts of mice that had been superovulated by injections of PMS and HCG. Some eggs, inseminated with spermatozoa that had been collected from caudae epididymides of mature male mice and cultured for two to three hours before insemination, were observed continuously on a glass slide under a phase microscope. Other eggs were inseminated in Petri dishes in a 5% CO2 incubator and examined every 20 minutes for 180 minutes. Compatible results in both sets of eggs showed that formation of the second polar body began 25-40 minutes after fusion of spermatozoon with the vitellus; it was completed 40-60 minutes later; anaphase II lasted approximately five minutes before the appearance of the furrow abstricting the second polar body. It is suggested that the furrowing associated with second polar body formation is guided by the same kind of forces that divide a cell mitotically.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979) 
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 193-199 
    ISSN: 0148-7280
    Keywords: double spermatozoa ; human prolactin-secreting adenoma ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In a man with a pituitary prolactin-secreting adenoma almost only double spermatozoa were produced. These cells were almost completely enveloped in a unique membrane, a common bilocular acrosome capped two paired nuclei, and all the other organelles were double. After 120 days of treatment with 2-brom-α-ergocryptine the prolactin level was corrected, and only normal, single spermatozoa were produced. The authors suggest that a high prolactin level inhibits cell division.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 201-206 
    ISSN: 0148-7280
    Keywords: zona pellucida ; antibody ; ovary ; calf ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Treatment of bovine ovary sections with rabbit antibovine zona serum followed by fluorescein-conjugated goat antirabbit IgG produced a specific fluorescent staining only of the zonae pellucidae. Fluorescence was greater near the inner and outer surface of the zona, suggesting that either the same antigen occurs in higher concentration in these regions or that there is more than one antigen, the most immunogenic being located peripherally. In some atretic follicles fluorescent material appeared to diffuse into the degenerating oocyte and into the intercellular spaces of the cumulus oophorus.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 213-222 
    ISSN: 0148-7280
    Keywords: urethan effect ; cleavage induction ; parthenogenesis ; sea urchin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effect of urethan on artificial induction of cleavage in eggs of the sea urchin, Hemicentrotus pulcherrimus, was studied. When the eggs were exposed for 20 minutes to seawater containing urethan (final concentration, 0.08 M) after butyric acid-activation and then treated with hypertonic seawater, the cleavage rate was enchanced by about 1.5 times as compared with the nontreated eggs. In the eggs exposed to urethan-seawater for over 70 minutes many clear spots appeared throughout the cytoplasm. Simultaneously, the pigment granules, which had been embedded within the cortex, migrated to the inner cytoplasm and encircled a monastral centrosphere and clear spots. The clear spots were composed of microtubules much like cytasters, and in the central region of them centrioles were not yet found. The eggs in which the pigment granules disappeared from the cortex may be more susceptible to cleavage induction by succeeding hypertonic treatment.
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  • 11
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979) 
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 12
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 35-42 
    ISSN: 0148-7280
    Keywords: activated motility ; temperature dependence of motility ; sperm transport ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The motility of rabbit spermatozoa recovered from the vagina, endocervix, uterus, and four regions of the oviduct was assessed visually by phase-contrast microscopy at intervals from one minute to 16 hours after a single mating. The percentage of motile cells in each sample was dependent on the temperature of recovery, ie, 23° vs 37°C, but was not influenced by the temperature of observation. Spermatozoa in the lower isthmus of the oviduct were the most temperature sensitive population to recovery at 23°C. When all manipulations and observations were performed at 37°C, the percentage of spermatozoa with progressive motility varied according to the region sampled and interval after mating. Populations from the vagina, uterus and upper regions of the oviduct usually had a high proportion of progressively motile cells with vigorous flagellar activity. Fewer spermatozoa showed progressive movement on recovery from the endocervix and lower 2 cm of the tubal isthmus and their flagellar activity was generally depressed. The decrease in flagellar beat frequency noted in the latter regions may be a major factor limiting sperm ascent in the female tract. A unique pattern of “activated” motility was seen exclusively in populations taken from the oviducts at 6 to 16 hours after mating. This motility pattern, consisting of alternating episodes of linear progressive and vigorous nonprogressive movement, may be analogous to the activated motility described for capacitated rodent spermatozoa.
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  • 13
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 75-87 
    ISSN: 0148-7280
    Keywords: acrosin ; activation ; inhibitor ; proacrosin ; spermatozoa ; zymogen ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The sperm-specific proteinase acrosin (EC 3.4.21.10) is found in spermatozoa as a zymogen. We have looked for different forms of this zymogen in testicular, epididymal, and ejaculated spermatozoa from ram and have compared total sperm extracts made immediately after cell disruption with extracts made later from isolated sperm heads. We have concluded that the autoactivatable zymogen form, known generally as proacrosin, is the only form of acrosin within intact mature ram spermatozoa; no other zymogen form was detected, although lower levels of proacrosin were found in some samples of testicular spermatozoa. From studies of the activation process, it appears that ram proacrosin is truly autoactivatable; no evidence could be found for the involvement of any auxiliary enzyme. Estimations of the molecular weight of proacrosin using gel chromatography (60,000) and SDS-polyacrylamide gel electrophoresis (51,300) indicated that the zymogen is monomeric. Comparison with the molecular weight of ram acrosin (44,000 or 40,000, using the two respective methods) indicated that a single acrosin molecule is derived from each zymogen molecule. The sperm acrosin inhibitor (molecular weight 11,000 or 8,000) was present in testicular spermatozoa as well as in ejaculated spermatozoa; there was no evidence that it was produced as a result of zymogen activation.
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  • 14
    ISSN: 0148-7280
    Keywords: spermatozoon-ostracoda (Heterocypris incongruens) ; external morphology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In various papers on the original spermatozoon of the Ostracoda, its helicoidal disposition has been indicated as the principle characteristic of this gamete, at cell structure level as well as in its external morphology. Through a combined study with scanning electron microscope (SEM) and transmission electron microscope (TEM), we have been able to establish the corresponding relationship between the cell architecture and the spermatozoon's external morphology. In the case of Heterocypris incongruens, the helicoidal relief of the gamete's external surface along the greatest part of its length, is the result of the twisting and undulating of a structure derived from the nucleus' external membrane, endoplasmic reticulum, and Golgi apparatus, called “feather-like organelle.” In keeping with the shape of this surface relief, the spermatozoon can be divided into three regions: An anterior one with a corkscrew form, a middle one showing a relief in the form of a screw with four threads, and a posterior or tail one without helicoidal relief. Finally, we discuss the different criteria existing on the possible orientation of this spermatozoon when it moves, as well as the functional advantages that the possession of a filiform, helicoidal, and mobile gamete represents.
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  • 15
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 121-124 
    ISSN: 0148-7280
    Keywords: oocyte maturation ; LH ; ovum culture ; germinal vesicle breakdown ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Immature rats, aged 27 days, were stimulated to develop preovulatory follicles by subcutaneous injection of 15 IU of pregnant mare serum gonadotrophin (PMSG). Two days later their oocytes were collected. They were cultured under conditions that permitted continuous observation. Times of the initial stages of maturation were carefully noted, in the absence and the presence of 10 μg/ml of bovine luteinizing hormone (LH). LH did not accelerate germinal vesicle disappearance. It was concluded that the immature PMSG-treated rat was not an appropriate model for the study of LH action; it was speculated that persistence of PMSG mimicked LH in all the oocytes from such donors.
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  • 16
    ISSN: 0148-7280
    Keywords: lysin ; protease inhibitor ; sea urchin ; vitelline coat ; fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To search the spermatozoa of sea urchins for their lysins, the eggs were inseminated in the presence of various protease inhibitors. Among them, two chymotrypsin-specific inhibitors, chymostatin and N-tosyl-L-phenylalanyl-chloro-methane, as well as p-nitrophenyl p′-guanidinobenzoate, inhibit fertilization of the sea urchins, Hemicentrotus pulcherrimus and Strongylocentrotus intermedius.A chymotrypsin-like protease is presumed to be a lysin of the sea urchins, since the inhibition of fertilization by chymostatin is remarkably diminished if the eggs are pretreated with trypsin or chymotrypsin to break the vitelline coat before insemination, and since N-tosyl-L-phenylalanyl-chloromethane, and p-nitrophenyl p′-guanidinobenzoate, as well as chymostatin, inhibit the fertilization.In all the sea urchins so far studied, elevation of fertilization envelopes is inhibited by leupeptin, antipain, soybean trypsin inhibitor, and p-nitrophenyl p′-guanidinobenzoate, all of which are potent trypsin inhibitors.Synthetic inhibitors have cytotoxic side effects on the eggs, but the microbial and plant inhibitors have no such effects.
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  • 17
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 223-233 
    ISSN: 0148-7280
    Keywords: seminal plasma DNase ; nicked sperm DNA ; sperm decondensation ; DNA template ; DNA phosphorylation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ejaculated rabbit spermatozoa washed with buffer prior to decondensation by Triton X-100 and dithiothreitol were good templates for DNA synthesis by Escherichia coli DNA polymerase. This result agrees with the observations of Zirkin and Chang [1977], and implies that the sperm DNA is nicked. Template activity, however, was reduced if spermatozoa were extensively washed before decondensation, and if DNase inhibitors EDTA or Na2SO4 were present during decondensation. Template activity was also low if decondensation was induced with DNase inhibitors thioglycollic acid, Na2SO3 or sodium dodecylsulphate and dithiothreitol instead of with Triton X-100 and dithiothreitol. Calf thymus DNA was completely degraded when incubated with rabbit seminal plasma or buffer-washed spermatozoa, but much less degradation was observed if EDTA, Na2SO4, thioglycollic acid, Na2SO3 or sodium dodecylsulphate were also present, or if spermatozoa were extensively washed with buffer. Centrifugation of spermatozoa through 2.05 M sucrose completely removed contaminating DNase, and such spermatozoa were inactive as DNA templates after decondensation. The DNA template activity of swollen rabbit sperm nuclei thus parallels the activity of a contaminating seminal plasma DNase. This suggest that the nicks in sperm DNA enabling it to act as a template for DNA synthesis were generated by the DNase during decondensation and thus are not a natural structural feature of the DNA. The presence of breaks in the DNA of decondensed buffer-washed spermatozoa (DNase contaminated) was confirmed by their incorporation of phosphate from [γ-32 P] ATP in the presence of the enzyme polynucleotide kinase. These spermatozoa were found to contain as few as two breaks/mole of DNA, but sucrose-washed spermatozoa (DNase free) were free of breaks. The possible use of this enzymic procedure for the assessment of sperm genome damage and the evaluation of the quality of a sperm population are discussed.
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  • 18
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979) 
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 19
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 265-282 
    ISSN: 0148-7280
    Keywords: sperm chromatin ; nuclease digestion ; sperm decondensation ; chromatin structure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The structure of rabbit, fowl, and Xenopus laevis sperm chromatin was explored by study of the reaction of their decondensed nuclei with DNase 1 and micrococcal nuclease. Those of rabbit and fowl were readily digested by DNase 1, and the polyacrylamide gel electrophoresis profiles of DNAs extracted from the digests were similar, each being polydisperse with a single discrete band of DNA smaller than 72 base pairs. There were differences, however, between the sperm chromatins in the course of their digestion by micrococcal nuclease. A limit digest at about 45% acid solubility was obtained with Xenopus sperm chromatin, while 90% of fowl sperm DNA was rendered acidsoluble by the enzyme. The gel profiles of the limit digests were polydisperse, but only those of rabbit and fowl sperm chromatins possessed a discrete band of DNA smaller than 72 base pairs. Bleomycin did not react with DNA of rabbit, fowl, or Xenopus spermatozoa. Since bleomycin reacts with somatic cell chromatin, and the course of DNase 1 or micrococcal nuclease digestion of sperm chromatin was different from that found for somatic cell chromatin, it would appear that sperm chromatin does not have the repeating nucleosometype structure of somatic cell chromatin. The nuclease digestion studies further suggest that the organization of rabbit and fowl sperm chromatins is similar, and is different from that of Xenopus sperm chromatin. The dependence of the structure of sperm chromatin on the composition of its basic proteins, and a possible structure for a protamine-type sperm chromatin, are discussed.
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  • 20
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 295-304 
    ISSN: 0148-7280
    Keywords: in vitro fertilization ; mouse ; sperm penetration ; zona pellucida ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Sperm penetration through the zona pellucida and fusion of the sperm head with the vitellus were observed continuously and filmed under phase optics in cumulus-free living mouse eggs inseminated in vitro with capacitated epididymal sperm. Most spermatozoa penetrated the zona pellucida, traversed the perivitelline space, and fused with the vitellus at an angle nearly perpendicular to the surface. The mean duration required for sperm to penetrate the zona pellucida was 20 minutes with a range of 15-26 minutes. Sperm traversed the perivitelline space in less than one second. The initial contact of sperm with the vitellus generally took place at the tip of the sperm head. When the tip of the sperm head contacted the vitellus there was an immediate reduction in the rate of flagellation, followed by the gradual sinking of the sperm head into the vitellus.
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  • 21
    Electronic Resource
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    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 357-366 
    ISSN: 0148-7280
    Keywords: ova ; spermatozoa ; cryopreservation ; fertilization ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mature unfertilized ova from superovulated hamsters were freed from all investments and frozen at -50°C. They were cooled at about 1°C/min to 0°C then at 0.8° to 0.6°C/min to -50°C. At 0°C, dimethyl sulfoxide was added to a final concentration of 1.25 M. The ova were stored at -50°C for up to four months. Thawing was performed at 2-4°C/min and followed by several washes with insemination medium. Approximately 90% of the ova were normal in appearance after thawing. The frozen and thawed ova with normal appearance could be penetrated by hamster or human spermatozoa at a rate comparable to unfrozen controls. The ability of hamster ova to tolerate storage at a relatively convenient temperature (-50°C) for long periods (tested for up to four months) makes possible their shipment at low cost to institutions lacking this resource. There they can be used for basic biological studies of sperm-egg interaction or in the clinical assessment of human sperm quality.
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  • 22
    Electronic Resource
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    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 1-13 
    ISSN: 0148-7280
    Keywords: capacitation ; acrosomal enzymes ; rabbit sperm ; acrosomal membranes ; fertilization ; lysosomal enzymes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Significant release of the acrosomal enzymes arylsulfatase, β-N-acetylhexosaminidase and hyaluronidase was observed following the treatment of ejaculated rabbit spermatozoa for 12 hours in 20% rabbit serum for inducing in vitro capacitation, and these sperm were capable of in vivo fertilization; however, the treatment of sperm for 15 minutes in high ionic strength (380 mOsm/kg) or low ionic strength medium (305 mOsm/kg) for in vitro capacitation did not result in any significant release of the above enzymes nor were the sperm capable of in vivo fertilization. Serum-treated spermatozoa remained significantly motile following the 12 hour treatment, 51% underwent the acrosome reaction and were capable of fertilizing 66% of the ova in vivo. Identical serum treatment of lysosomes from rabbit liver resulted in a comparable release of the lysosomal enzymes. Serum treatment for in vitro capacitation resulted in vesiculation of the anterior margin of half the spermatozoa, but left their inner acrosomal membranes and equatorial segments intact. A biochemical relationship between the release of acrosomal enzymes and capacitation is suggested.
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  • 23
    ISSN: 0148-7280
    Keywords: fertilization ; acrosome reaction ; sea urchins ; cross-fertilization ; species specificity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Sperm of Hemicentrotus pulcherrimus undergo the acrosome reaction in the jelly coat or on the surface of the vitelline layer of Pseudocentrotus depressus eggs and can fertilize the latter, whereas those of P depressus do not undergo the acrosome reaction even after they strike the vitelline layer of H pulcherrimus eggs and cannot cross-fertilize.In the latter combination, however, if cross-insemination is performed in the presence of homologous egg water, cross-fertilization becomes less difficult than in normal seawater, and percentage cross-fertilization rises as does percentage acrosome reaction. It is suggested that the cross-fertilizability of this combination depends highly on the inductivity of the acrosome reaction. The reason why such a causal relation is observed is discussed.
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  • 24
    Electronic Resource
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    New York, NY : Wiley-Blackwell
    Gamete Research 2 (1979), S. 25-34 
    ISSN: 0148-7280
    Keywords: spermatozoa ; spermiogenesis ; male germ cells ; centriole ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the course of the reorganization and degeneration of the proximal centriole in the mature acentriolate spermatozoon of the Mongolian gerbil, both the proximal and distal centrioles appear in the early cap phase of spermatid development. During the acrosome phase, both distal and proximal centrioles become highly active in the formation of a segmented column. The proximal centriole becomes actively involved in the formation of the capitulum, while the distal centriole forms the axonemal complex and dense fibers. During the maturation phase of spermatid development, the “pinwheel” arrangement of the proximal centriole becomes an “S”-shaped structure, turned 90° on its vertical axis. The few “doublet” microtubules that can be detected later in that stage completely disappear during spermiation. The distal centriolar area develops a single central pair of microtubules and membranous elements. Another prominent feature in the neck region of the gerbil spermatozoa is the presence of two dense rudimentary columns in association with the mitochondria. Although their density is similar to that of the other columns, these two columns have no connection with the dense fibers; in fact, they are closely associated with the mitochondria.
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    Gamete Research 2 (1979), S. 53-64 
    ISSN: 0148-7280
    Keywords: spermatozoa ; plasma membrane ; glycoproteins ; free acidic groups ; farm mammals ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ejaculated spermatozoa of boars, bulls, rabbits, and rams were embedded in glycolmethacrylate and thin sections stained with phosphotungstic acid at low pH in order to observe the distribution of glycoproteins of the plasma membrane. Colloidal iron hydroxide was also used to detect the free acidic groups present on the sperm surface. Species-specific patterns of localizations of glycoproteins and linked negative charges were observed. The distribution was sometimes homogeneous as in bull, but generally heterogeneous in the other species. The significance of the results on sperm surface components and the practical interest to know their normal distribution are discussed.
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  • 26
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    Gamete Research 2 (1979), S. 43-51 
    ISSN: 0148-7280
    Keywords: spermatozoa ; acrosome ; glycoproteins ; farm mammals ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ejaculated spermatozoa of boars, bulls, rabbits, and rams were fixed with glutaraldehyde and embedded in glycolmethacrylate. Thin sections were treated with phosphotungstic acid at low pH in order to localize cellular glycoproteins stained by the PAS technique at the light microscope level. At the ultrastructural level the glycoproteins were segregated in the anterior segment of mature spermatozoa. The distribution of these glycoproteins in the anterior segment was not homogeneous; it appeared species-specific in detail, but as a rule, the maximum concentration was observed in a superficial layer, especially in the marginal thickening. The localization of other acrosomal components (eg, crystalline and basic proteins) is also reviewed. The origin and significance of the segregation of proteins and glycoproteins in the acrosome are discussed in relation to the fact that the acrosomal enzymes analyzed so far are glycoproteins.
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  • 27
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    Gamete Research 2 (1979), S. 65-73 
    ISSN: 0148-7280
    Keywords: embryo transfer ; embryo culture ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Embryo transfer experiments were carried out to study the developmental capacity of cultured rabbit embryos when transferred to recipients of variable postovulatory maturity. Rabbit embryos were flushed from the oviduct at 26 hours postcoitum (pc) and cultured in a modified Ham's F-10 medium supplemented with bovine serum albumin (BSA) for a period of 70 hours. At 96 hours pc the cultured embryos, which ranged from the early morula to the expanding blastocyst stage, were transferred to pseudopregnant recipients mated to vasectomized males 36 to 96 hours prior to the transfer procedure. Greatest embryo survival occurred when transfers were made to either the oviducts or uterine horns of recipients at 48 hours pc. Intermediate results for both implantation rates and number of young born were obtained with recipients at 36, 60, 72, and 84 hours pc. Transferred embryos consistently failed to survive the uterine environment of recipients 96 hours pc at transfer although this group was synchronous with embryonic chronological age. Oviductal transfers were generally more successful than uterine transfers. Markedly higher rates of embryo survival resulted from embryos that were collected 60 and 72 hours pc and transferred directly to synchronous recipients without an interim period of culture. Dissimilarity of development for in vivo grown rabbit embryos and those cultured in synthetic medium is demonstrated.
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    Gamete Research 2 (1979), S. 99-104 
    ISSN: 0148-7280
    Keywords: sperm penetration ; premature cortical reaction ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The method of in vitro fertilization was applied to test a previous suggestion that the lowered fertilizability of the tubal oocytes of female KE strain mice and the high resistance of their zona pellucida to proteolytic enzymes, are due to the premature cortical reaction taking place near the time of ovulation. Therefore higher fertilizability of ovarian oocytes is expected.The effectiveness of F1 hybrid sperm penetration into ovarian and tubal KE oocytes confirmed these assumptions. The ovarian KE oocytes recovered 9-10 hours after administration of human chorionic gonadotropin (HCG) showed significantly higher penetrability (70-83%) than did the tubal oocytes recovered 12 hours after HCG (about 50%) and 14-16 hours after HCG (20%).Similar results were obtained with C57 oocytes. Sperm penetration into ovarian oocytes (10 hours after HCG) was much more effective (67%) than into tubal oocytes (18%); this finding correlated with more rapid zona dissolution by chymotrypsin. On the basis of these results one might speculate that premature cortical reaction takes place also in the C57 strain.
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    Gamete Research 2 (1979), S. 105-105 
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 30
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    Gamete Research 2 (1979) 
    ISSN: 0148-7280
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 31
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    Gamete Research 2 (1979), S. 137-145 
    ISSN: 0148-7280
    Keywords: progesterone-induced maturation ; methylxanthines ; chloera toxin ; phosphorylation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: During the course of maturation of Xenopus laevis oocyte a burst of phosphorylation occurs around germinal vesicle breakdown. At the same time a relative drop in a unique phosphoprotein (protein I; mot wt ∼40,000) is observed. Enucleation of [32P] labeled oocytes has shown the cytoplasmic localization of protein I. Methylxanthines and cholera toxin, which inhibit progesterone-induced maturation, block the burst of phosphorylation and do not change the amount or the distribution of [32P] phosphoproteins.
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  • 32
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    Gamete Research 2 (1979), S. 125-135 
    ISSN: 0148-7280
    Keywords: oogenesis ; oocyte growth ; Xenopus laevis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: When female Xenopus laevis are injected with [3H]-vitellogenin or [14C] N-acetyl glucosamine, most of the labeled material becomes associated three days later with oocytes having a diameter of 0.9-1.1 mm; smaller and larger oocytes are less labeled. With time, the pattern of labeling shifts to larger oocytes, indicating that those oocytes initially labeled continue to grow. We have measured such shifts as a function of time to provide estimates for oocyte growth rates from the end of stage III (diameter = 0.6 mm) to stage VI (diameter = 1.2 mm). The total time required for oocytes to progress through this size increase is 16-24 weeks in unstimulated females and 9-12 weeks in human chorionic gonadotropin (hCG)-stimulated females. The fastest rate of growth occurs from mid-stage IV (approximately 0.8 mm diameter) until midstage V (1.2 mm diameter), which corresponds to the period of most pronounced vitellogenin uptake. The relative proportion of oocytes within this size range is also reduced, as predicted under steady-stage conditions. Evidence is also presented which indicates that the steady-state level of full-grown oocytes is maintained by a combination of replenishment and atresia. These results provide the first description of the kinetics of oocyte growth in X laevis females maintained under normal laboratory conditions and should be useful for any considerations of macromolecular events occurring during oogenesis.
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    Zeitschrift für die chemische Industrie 91 (1979), S. 447-448 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
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    Topics: Chemistry and Pharmacology
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    Zeitschrift für die chemische Industrie 91 (1979), S. 450-450 
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    Keywords: Chemistry ; General Chemistry
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    Zeitschrift für die chemische Industrie 91 (1979), S. 450-450 
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    Zeitschrift für die chemische Industrie 91 (1979), S. 451-451 
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    Zeitschrift für die chemische Industrie 91 (1979), S. cpi 
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    Zeitschrift für die chemische Industrie 91 (1979), S. 518-519 
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    Zeitschrift für die chemische Industrie 91 (1979), S. 519-520 
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    Zeitschrift für die chemische Industrie 91 (1979), S. 550-560 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
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    Topics: Chemistry and Pharmacology
    Notes: Wie die Anwendung chromatographischer Techniken ergab, sind Lipide mit langkettigen Alkyl- oder 1-Alkenylketten - Alkoxylipide oder Etherlipide genannt - in menschlichem und tierischem Gewebe weit verbreitet. Man unterscheidet neutrale Alkoxylipide, d. h. 1-O-Alkyl- oder 1-O-(1-Alkenyl)-2, 3-di-O-acylglycerole, und ionische Alkoxylipide, die an C-3 über einen Phosphat-Rest mit Aminoethanol, Cholin oder Serin verknüpft sind. 1-O-Alkylglycerole, 1-O-(1-Alkenyl)glycerole und andere natürlich vorkommende Alkoxylipide können mit hohen Ausbeuten synthetisiert werden. Auch 2-Alkyl-, 1, 3-Dialkyl- und Trialkylglycerole, die in der Natur nicht vorkommen, sind synthetisch zugänglich. Die neutralen Alkoxylipide werden für bio-medizinische Untersuchungen verwendet, z. B. als Substrate in Systemen mit Acyl-Hydrolasen oder bei Untersuchungen der Fettresorption. Die Biosynthese der Alkoxylipide ist in großen Zügen aufgeklärt. Der Alkyl-Rest stammt aus einer gesättigten oder einfach-ungesättigten Fettsäure. 1-O-(1-Alkenyl)-2-O-acylglycerophosphorylaminoethanole („Plasmalogene“) werden offenbar aus den entsprechenden 1-Alkylverbindungen gebildet; in der Cholin-Reihe ist das nicht möglich. Trotzdem kommen „Aminoethanol-“ und „Cholin-Plasmalogene“ in den meisten Geweben gemeinsam vor.
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    Zeitschrift für die chemische Industrie 91 (1979), S. 1024-1025 
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    Keywords: Chemistry ; General Chemistry
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    Zeitschrift für die chemische Industrie 91 (1979), S. 1025-1026 
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    Keywords: Chemistry ; General Chemistry
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    Zeitschrift für die chemische Industrie 91 (1979), S. 1026-1028 
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    Keywords: Chemistry ; General Chemistry
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    Zeitschrift für die chemische Industrie 91 (1979), S. 1028-1030 
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    Zeitschrift für die chemische Industrie 91 (1979), S. 1032-1032 
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    Journal of Morphology 159 (1979), S. 151-183 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The unusual lymphogranulopoietic bone marrow of the large lungless salamander Plethodon glutinosus was examined by light and electron microscopy. Developing neutrophils, eosinophils, and fat cells were found in large numbers, while lymphocytes of various sizes, plasma cells, plasmablasts, macrophages, pigment cells, and fibroblasts were present in more moderate numbers. Basophils were observed only rarely. Macrophages were found in extravascular locations and did not appear to be associated directly with the walls of the blood vessels supplying the marrow. Both neutrophils and eosinophils seemed to arise from small precursor cells whose ultrastructural features bore a resemblance in some ways to those of mammalian myeloblasts described by Bainton and Farquhar ('66). Developing neutrophils and eosinophils seemed to produce only single populations of specific cytoplasmic granules, rather than both primary (azurophilic) and secondary (specific) inclusions, as are produced typically by mammalian granulocytes. Both eosinophilic and neutrophilic granules were formed in association with Golgi complexes; and eosinophilic granules were much larger, more densely stained, and more regularly rounded in shape than the inclusions of developing neutrophils. Peroxidase activity was associated with the specific granules of neutrophils but seemed to be lacking in the granules of eosinophils. The specific granules of eosinophils were especially unusual because they contained irregularly shaped, lightly stained cores which occasionally displayed a distinctly crystalline substructural organization. The specific granules of basophils also possessed a prominent crystalline organization. The overall appearance of the marrow of Plethodon suggests that it functions not only as a valuable source of neutrophils, eosinophils, and cells of the lymphoid series, but also as a part of the phagocytic system of the animals and as an important repository for fat.
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Topics: Biology , Medicine
    Notes: When Aedes aegypti females first emerge as adults, their oocytes possess no yolk. The abdominal fat body cells contain large quantities of lipid, protein, and glycogen, and possess many free ribosomes, but have very little rough endoplasmic reticulum (RER). When the females are starved for four days, their oocytes form fine lipid and protein yolk endogenously, the latter being located mainly around the nucleus. The adipocytes in these fasted mosquitoes have greatly reduced amounts of lipid, protein and glycogen and contain many cytolysosomes. Seven hours after 4-day-starved females had fed on blood, their oocytes begin filling with exogenous protein yolk at the oolemma, and lipid arises endogenously throughout the ooplasm. At this hour, the fat cells have synthesized more RER than is seen in unfed controls. Twenty-four hours post blood meal, the follicle cells have secreted discrete endochorionic plaques onto the oolemma. At this period, the adipocytes are densely filled with RER, and show for the first time many Golgi bodies and protein inclusions. They have noticeably less glycogen than at seven hours. Within 48 hours after mosquitoes have fed on blood, the endochorion forms a continuous layer around the steadily enlarging egg which is synthesizing additional protein and lipid yolk. Concurrently, the adipocytes show a greatly increased amount of glycogen and a significant reduction of RER. By the sixtieth hour after the blood meal, the follicle cells are attenuated, and the fat cells have less RER and more glycogen than at 48 hours. The nurse cells steadily decrease in size during vitellogenesis and release material onto the micropyle.
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    Journal of Morphology 159 (1979), S. 221-232 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The electron microscopical structure of the type “B” cells in the rectal pad epithelium of Locusta is described. The type “B” cells occur singly in the distal region of the rectal pad epithelium. They are characteristically goblet shaped and join with contiguous type “A” or rectal pad cells, near the apical surface by means of a restricted region of septate desmosomes. Type “B” cells possess a microvillate apical membrane, with the villi arranged as a rosette overlying the apical inaginations of adjacent type “A” cells.Large numbers of microtubules and vacuoles of various sizes containing an assortment of inclusions are present in the apical region of the type “B” cells. Many of the microtubules insert distally on hemidesmosomes located in the apical plasma membrane. Rough endoplasmic reticulum and mitochondria are also present but neither are abundant. The possible significance of these findings is discussed.
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    Notes: The central nervous system of the sessile barnacle, Semibalanus cariosus (Pallas), has been studied with the particular aim of determining the locations of neuron somata in relation to peripheral nerves. This was accomplished by tracing peripheral nerves using dissection and methylene blue staining techniques, histological methods, and by permitting cobaltous chloride to diffuse via axons into ganglia (“backfilling”).The neuron maps resulting from the study reveal some well-defined sub-systems, a considerable degree of functional clumping of neuron somata, and some unexpected projections of neurons in the CNS. Neurophysiological studies based on these findings are in progress.
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    Journal of Morphology 159 (1979), S. 311-329 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Normal development of the urostyle is described during late stages of metamorphosis in five species of anurans: Xenopus laevis (Daudin), Bufo americanus Holbrook, Pseudacris triseriata (Wied), Hyla chrysoscelis Cope, and Rana pipiens Schreber. The developing urostyle of all five species is composed of essentially the same cartilaginous elements: one pair of basidorsals above the notochord and the subtended hypochord. Among the five species there is variation in such details as the number of spinal nerve foramina and the degree of fusion of the basidorsals; however, both the hypochord and basidorsals are very similar in all five genera examined. Consideration of the literature suggests that contradictory descriptions of the developing urostyle result from (1) varied methods of study (alizarin-staining of whole specimens or serial cross-sections), (2) the variety of species examined, and (3) the particular stage of development of the tadpole described by an investigator.
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    Journal of Morphology 159 (1979) 
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    Notes: Fine structure of the scales of Fundulus heteroclitus was examined by scanning and transmission electron microscopy. The concentric ridges of the scale surface were characterized by the presence of minute, highly calcified, denticles or tooth-like processes. Needle-shaped crystals of hydrox-yapatite were precipitated not only in the osseous layer but in the intimate lamellae of the fibrillary plate except in portions just below the grooves. The calcification of the osseous layer was observed to proceed by filling the matrix with patches of crystals. The fibrillary plate appeared to calcify by invasion of crystals from the upper calcified zone into spaces between collagen fibers.
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    Journal of Morphology 159 (1979), S. 81-87 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Topics: Biology , Medicine
    Notes: Study of the fine structure of the macronucleus in Euplotes eurystomus, a ciliate protozoon, during various stages of the cell division cycle has yielded new information about intranuclear helices. They are frequently observed at the periphery of chromatin bodies or next to the nuclear envelope, and they appear to be a constituent of nucleoli. The fibril that forms a helix is about 11-15 nm thick, and torus profiles of helices cut in cross section are about 35 nm in diameter. In substructure the helix is composed of a thin strand 3-5 nm thick which is coiled to form the 11-15 nm fibril; so the helix is a super-coiled structure. The intranuclear helices are present in the macronucleus throughout the cell cycle. They do not show obvious changes of relative abundance nor changes of relative localization in the nucleus, with one exception: they were never observed in the diffuse zone of replication bands. Evidence is presented indicating that nuclear helices migrate to the cytoplasm through nuclear pores. Although the chemical composition of the Euplotes intranuclear helices is unknown, information in the literature on similar helices in Amoeba indicates that they contain RNA and not DNA. The observations on Euplotes helices are consistent with a concept of “packaged” RNA for transport to the cytoplasm.
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    Journal of Morphology 160 (1979), S. 299-321 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Nematode amphids are a pair of lateral cephalic sense organs, each comprising a group of sensory endings terminating in a cuticle-lined pit. In Syngamus trachea, a parasite of birds, each amphid is surrounded by two non-nervous supporting elements, a large gland cell basally and a smaller supporting cell anteriorly. The amphidial glands display high levels of secretory activity from five to six days postinfection. Secretory material is discharged through the lumen of the sense organ onto host tissue. The ultrastructure of amphids and amphidial glands has been investigated in newly moulted, immature and mature adults to trace the development of glandular activity and its effect on amphid-amphidial gland relationships. In newly moulted adults, the glands have very low levels of secretory activity and appear to act only as supporting cells to the amphids. As secretory activity increases, the gland cell membrane surrounding the sensory endings is elaborated into a reticulum which probably forms the secretory surface. In mature adults the amphid pit is swollen and filled with secretion; the sensory endings are relegated to the periphery of the lumen. It is suggested that amphidial glands develop from typical supporting cells, but acquire a new role possibly associated with parasite attachment.
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    Journal of Morphology 159 (1979) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 63
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    Journal of Morphology 159 (1979), S. 131-143 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Eggs of the turtle Trionyx spiniferus are rigid, calcareous spheres averaging 2.5 cm in diameter. The eggshell is morphologically very similar to avian eggshells. The outer crystalline layer is composed of roughly columnar aggregates, or shell units, of calcium carbonate in the aragonite form. Each shell unit tapers to a somewhat conical tip at its base. Interior to the crystalline layer are two tertiary egg membranes: the outer shell membrane and the inner shell membrane. The outer shell membrane is firmly attached to the inner surface of the shell, and the two membranes are in contact except at the air cell, where the inner shell membrane separates from the outer shell membrane. Both membranes are multi-layered, with the inner shell membrane exhibiting a more fibrous structure than the outer shell membrane. Numerous pores are found in the eggshell, and these generally occur at the intersection of four or more shell units.
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  • 64
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    Journal of Morphology 161 (1979), S. 1-21 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: As a part of a continuing study of unusual molluscan tissues, the “chondroid” tissue (Hyman, '67) associated with the anterior and posterior aortae of the slug (Limax maximus) was examined by light and electron microscopy. Unlike the odontophoral tissue of this species (Curtis and Cowden, '77), the “chondroid” tissue comprising the adventitial layer of the aorta consists of large, glycogen-filled cells with characteristic arrays of pores in their plasma membranes resembling those of the “globular” cells (Rogers, '69; Fernandez, '71); “fibrocytes” (Nicaise et al., '66; Baleydier et al., '69; Nicaise, '73); “Blasenzellen” or “Leydig” cells (Wondrak, '69; Stang-Voss, '70; Buchholz et al., '71; Stang-Voss and Staubesand, '71; Wolburg-Buchholz, '72); or “pore” cells (Sminia, '72; Beltz, '77) of other mollusks. The anterior and posterior aortae are very similar in organization, except that the anterior aorta is larger in diameter; its wall is thinner; and it lacks calcification. Both the anterior and posterior aortae possess a loosely organized (incomplete) endothelial layer surrounded by two layers of innervated smooth muscle. The smooth muscle cells possess fibrous surface specializations resembling hemidesmosomes as well as large numbers of tubular or rounded vesicles in association with their plasma membranes. Blood cells (amoebocytes) containing large glycogen deposits and distinctive membrane-enclosed cytoplasmic inclusions can be found occasionally in the walls of the vessels.
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  • 65
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    Journal of Morphology 161 (1979), S. 23-38 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Glycogen metabolism has been studied during the development of the early chick embryo, at the cytochemical and ultrastructural levels. Two waves of glycogen synthesis and breakdown have been found. In the first, free clusters of glycogen particles are synthesized at late oogenesis. These clusters are found later in invaginations of the membrane of vesicles containing a floc-cular material (FLOV). The glycogen clusters are degraded there during ovulation and the first hours in the oviduct. The second wave of glycogen synthesis begins before cleavage, reaching a maximum at mid-uterine age. This second wave occurs in another type of vesicle (GLYV), which eventually disintegrates releasing free clusters of glycogen granules. This glycogen is degraded in membranous structures containing a floccular material, as in the first wave of degradation. The degradation ends at the late uterine stages, and at the same time numerous ribosomes are formed. This period corresponds to area pellucida formation, which probably depends on the energy liberated during the second wave of glycogen degradation.
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  • 66
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    Notes: A sensory papilla is described in the eyestalk of the crayfish Astacus leptodactylus during the last embryonic stages and during larval stages by light microscopy. This region was also investigated with the scanning electron microscopy, which showed sensory hairs in the postmolt adult; they disappear during intermolt and premolt. Simultaneous cyclic changes in hair papillae are observed in the hypodermis. The possibility of a chemoreceptive function is discussed.
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  • 67
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    Journal of Morphology 161 (1979), S. 53-77 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Formation of nuclear envelopes during the last cleavage mitosis and the formation of the cell membranes during the cellularization of the blastoderm have been studied ultrastructurally in the blowfly egg. Dense bodies arising from yolk granules by budding could contain membrane material destined to be incorporated into the new membranes of the blastoderm. The presence of transitional structures indicates that these bodies can be converted into dark multivesicular bodies. Large amounts of endoplasmic reticulum are found around the mitotic nuclei. Clusters or branched chains of vesicles associated with this are interpreted as evidence for the formation of endoplasmic reticulum by the breakdown of dark multivesicular bodies. Nuclear envelopes of mitotic daughter nuclei probably originate from endoplasmic reticulum. The egg contains both intranuclear and extranuclear annulate lamellae.The main events of cytokinesis are furrow initiation and cell membrane growth during the slow first phase, but probably only cytokinetic movement during the rapid second phase. On the assumption that cell membrane growth occurs by incorporation of complete membrane pieces, the addition of coated vesicles and/or light multivesicular bodies is definitely most probable. Some intermediate profiles indicate that light and dark multivesicular bodies are related. The membrane needed for second phase cytokinesis could well be provided by the unfolding of surface microvilli and protuberances of the furrow canal.
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  • 68
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    Journal of Morphology 161 (1979) 
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  • 69
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    Journal of Morphology 161 (1979), S. 79-109 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The hindgut of the semi-terrestrial tardigrade, Milnesium tardigradum was examined with light and electron microscopy. The hindgut consists of a cloaca and an anterior hindgut. It is delineated anteriorly by the pylorus into which four Malpighian tubules empty and posteriorly, by a broad cloacal slit. A single oviduct enters the hindgut at the junction between the cloaca and the anterior hindgut. Two pairs of muscles insert on the cloaca and anterior hindgut respectively. Electron microscopic observations demonstrate that the anterior hindgut is a specialized transporting epithelium. The luminal surface is covered by a thin layer of cuticle which penetrates into channel-like invaginations. Numerous mitochondria are concentrated apically. The basal and lateral surfaces are also folded. The cells are joined apically by deep tight junctions and a simple basal lamina lines the entire hindgut. The cloaca which receives the contents of the gut and Malpighian tubules as well as gametes of the reproductive tract is a transitional organ that exhibits several characteristics of the hypodermis and anterior hindgut. The cuticle of the cloaca changes sequentially from the complex structure of the integument to a simple layer of the anterior hindgut. The function of the hindgut is discussed with emphasis on the possible response of the anterior hindgut to a hypoosmotic habitat, evaporative water loss during the induction of anhydrobiosis and low oxygen tension.
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  • 70
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    Journal of Morphology 161 (1979), S. 111-121 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Reticulate scales develop as radial symmetrical anlagen, in contrast to scuttate scales which appear initially as “epidermal placodes.” Unlike scuttate scales whose outer and inner epidermal surfaces elaborate β-and α-type keratins, respectively, reticulate scales elaborate only one type of epidermal surface which has been reported to give an α-type, X-ray diffraction pattern. We find that, histologically and ultrastructurally, this surface differs from either epidermal surface of scuttate scales. The keratinizing cells become filled with long interweaving bundles of α-filaments which aggregate into rather homogeneous α-fibrils. Keratohyalin granules, which have been shown to be associated with other keratinizing regions in the bird, do not form during the keratinization of reticulate scale epidermis.
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  • 71
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    Journal of Morphology 161 (1979), S. 157-167 
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    Notes: The mouthparts of female Corethrella brakeleyi and C. wirthi were studied using light and electron microscopy. Mandibles, hypopharynx and labium are highly sclerotized and are modified for obtaining blood meals. All structures were larger in C. brakeleyi than in C. wirthi except mandibular and hypopharyngeal teeth; these were smaller and more numerous in C. brakeleyi. The labium of both species terminates in peg-like structures which are similar to those reported from several genera of mosquitoes. Sensillae on the second segment of the maxillary palps appear to be identical to those described in both biting and nonbiting male and female blackflies.
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    Journal of Morphology 161 (1979), S. 169-175 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The vascular anatomy of five beavers (Castor canadensis) was studied by dissection and injection of arteries and veins with vinyl acetate. There is extensive countercurrent arrangement of arteries and veins distal to and including the common iliac artery and veins. Two types of countercurrent vessels occur (1) a venae comitantes type in which two or three veins surround a central artery, and (2) a modified rete type. The retia are located proximal to the large flat tail and the webbed hind feet. Two bypass veins are described for the feet and tail and the significance of these structures in temperature regulation is stressed.
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  • 73
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    Journal of Morphology 161 (1979), S. 123-143 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Blood follicles of the earthworm Amynthas are hemoglobin-containing, sac-like dilatations of blood vessels which connect to the general circulation. Grape-like clusters of follicles are found posterior to the pharynx, among tufts of micronephridia, and single follicles are located among cells of the pharyngeal gland. In Lumbricus, follicles take the form of simple swellings and irregular-shaped diverticula of nephridial capillaries.The fundamental structure of the wall of follicles and of vessels in both genera is the same and consists of two layers: an extracellular vascular lamina and an outer (coelomic) covering of smooth muscle-like myoperithelial cells. Hemocytes may be free and circulating or they may facultatively attach to the vascular lamina as littoral cells, constituting an incomplete endothelium-like surface. Hemocytes that appear to be in the process of attaching or detaching are rounded, while adherent cells are flattened and elongate. Free and littoral hemocytes actively endocytose packets of circulating extracellular hemoglobin.Hemocytes within follicles possess radiating cell processes which also endocytose hemoglobin. Although these cells were presumed to secrete hemoglobin, staining with 3,3′-diaminobenzidine confirms the presence of hemoglobin only within pinosomes and not within protein-synthesizing or packaging organelles. The presence of hemosiderin-like bodies suggests that follicular hemocytes catabolize hemoglobin.Blood follicles apparently provide a means of significantly increasing cell-surface area for hemoglobin processing, without substantially increasing the volume and pumping load of the circulatory system.
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  • 74
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    Journal of Morphology 162 (1979), S. 67-75 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: The role of dying cells in the optic stalk in relation to retinal fiber migration was investigated in the chick embryo. Cell death was analysed at various stages of development by counting pycnotic nuclei and also by the Gomori acid phosphatase reaction, while nerve fibers were visualised by the Bodian method. A wave of cell death, beginning in the neural retina at stage 18 and advancing with time through the stalk towards the diencephalon, occurred simultaneously or slightly prior to differentiation and migration of ganglion cell axons. Cell death stopped and gliogenesis occurred in the stalk after penetration by retinal fibers. Cell death occurred in the stalk even when fiber penetration was prevented by optic cup ablation. In this case, necrosis ensued until almost complete degeneration of the stalk, usually within three days after the operation, and gliogenesis did not occur. As the stalk degenerated, its cells became heavily pigmented. These observations suggest that the onset of cell death in the optic stalk is determined prior to and independently of retinal fiber penetration. On the other hand, cessation of cell death and subsequent gliogenesis occur only in the presence of ingrowing optic fibers.
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  • 75
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    Journal of Morphology 162 (1979), S. 17-36 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The optic tectum is a major subdivision of the visual system in reptiles. Previous studies have characterized the laminar pattern, the neuronal populations, and the afferent and efferent connections of the optic tectum in a variety of reptiles. However, little is known about the interactions that occur between neurons within the tectum. This study describes two kinds of interactions that occur between one major class of neurons, the radial cells, in the optic tectum of Pseudemys using Nissl, Golgi and electron microscopic preparations.Radial cells have somata which bear long, radially oriented apical dendrites from their upper poles and short, basal dendrites from their lower poles. They are divided into two populations on the basis of the distribution of their somata in the tectum. Deep radial cells have somata densely packed in the stratum griseum periventriculare. Their plasma membranes form casual appositions. Middle radial cells have somata scattered throughout the stratum griseum centrale and stratum fibrosum et griseum superficiale and do not contact each other. The apical dendrites of both populations of radial cells participate in vertically oriented, dendritic bundles. The plasma membranes of the dendrites in these bundles form casual appositions in the deeper tectal layers and chemical, dendrodenritic synapses within the stratum fibrosum et griseum superficiale. The synapses have clear, round synaptic vesicles and slightly asymmetric membrane densities. Thus, radial cells interact via both casual appositions and chemical synapses.These interactions suggest that radial cells may form a basic framework in the tectum. Because both populations of radial cells extend into the stratum fibrosum et griseum superficiale and stratum opticum, they may receive input from some of the same tectal afferent systems. Because the deep radial cells alone have somata and dendrites in the deep tectal layers, they may receive additional inputs that the middle radial cells do not. Neurons in the two populations interact via chemical dendrodendritic synapses, thereby forming vertically oriented modules in the tectum.
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  • 76
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    Journal of Morphology 162 (1979), S. 175-209 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The present investigation has examined the ultrastructural differentiation of the genital ducts of both sexes of fetal mice. The emphasis of observations was placed on the phenomenon of morphogenetic cytolysis, particularly during the critical periods of Wolffian duct stabilization and Mullerian duct involution.Both developing and regressing genital ducts evidence extensive cytolysis. Autophagy appears to be the mechanism of morphogenetic change in the developing male Wolffian duct. Autophagy, heterophagy, and degeneration in situ are all prominent cytolytic activities in female Wolffian duct involution. The developing female Mullerian duct undergoes extensive morphogenetic remodeling by the mechanisms of autophagy, heterophagy, and degeneration in situ. In the male Mullerian duct, autophagy, heterophagy, and degeneration in situ are also prominent. In addition, whole degenerated epithelial cells are extruded from the duct early in regression which may be related to the transformation of periductal mesenchymal cells into an “epithelioid cell cuff” which does not form around the regressing Wolffian duct. The formation of this mesenchymal condensation surrounding the duct is also accompanied by the protrusion of Mullerian epithelial cell cytoplasm into the mesenchymal cells. These observations may evidence a complex epithelial-mesenchymal interaction occurring during male Mullerian duct involution.
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  • 77
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    Journal of Morphology 162 (1979), S. 211-219 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: New schemata of the liver are presented to discuss the combination of the three kinds of liver lobules known until today in a chalk-talk-manner. Terminology is also discussed. Further investigations are needed involving the construction and the vascular pattern of compound lobules of the three individial lobules of the liver in different species.
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  • 78
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    Journal of Morphology 162 (1979), S. 221-247 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The light and electron microscopic structure of the pineal complex of the domestic goose was studied. The complex is tubulofollicular but there is no direct connection between the constituent system of ducts and the third ventricle of the brain. Within the pineal, blood vessels accompanied by sympathetic nerve bundles are confined to the connective tissue. Other nerve fibers and occasional nerve cell bodies, however, do occur among the pineal cells.Three basic pineal cell types were distinguished: (1) elongate epithelial cells which are arranged around follicles and ducts and resemble degenerate photo-receptor cells; (2) intramural supportive cells which are interspersed with elongate epithelial and intramural supportive cells; and (3) small supportive cells which lie between the bases of the elongate epithelial and intramural supportive cells. The follicular structure, vascularization, presence of secretory granules, and the nature of the elongate epithelial cells indicate that the pineal complex is primarily endocrine though a possible photoreceptive function cannot be ignored. Vesicles, 100-300 and 40-100 nm wide, were found within nerves and intramural supportive cells. The larger vesicles, present in pineals collected in the night, probably contain peptidic hormones. The smaller vesicles present in both day and night samples probably contain aminergic hormones.
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    Journal of Morphology 159 (1979), S. 331-341 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of tooth crowns is variable inter-specifically among caecilians. Cusp number and shape, crown dimensions, and crown curvature characterize various species and have both functional and phylogenetic implications. Ichthyophis, Uraeotyphlus, Hypogeophis, and Geotrypetes have bicuspid teeth; Dermophis, Gymnopis, Caecilia, and Typhlonectes monocuspid. Crown morphology as revealed by scanning electron microscopy is associated with prey grasping and, in one case, possible specialization of prey type.
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  • 80
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    Notes: The thymus glands of adult slimy salamanders (Plethodon glutinosus) were examined by light and electron microscopy with the objective of describing the populations of epithelial cells believed to be secretory. The results of various histochemical procedures designed to demonstrate nucleic acids, proteins, lipids, and mucosubstances were evaluated by light microscopy. Each thymus is incompletely subdivided into a variable number of interconnected lobules by trabeculae extending inward from a thin capsule composed of connective tissues. The thymic parenchyma lacks distinct cortical and medullary regions, although developing lymphocytes and plasma cells tend to accumulate in larger numbers in the outermost portions of the gland. Basophils are found regularly in the capsule and trabeculae, but only very rarely within the thymic parenchyma. The epithelial cells of the thymus can be classified into five categories: epithelial reticular cells; three varieties of granulated cells (types I, II, and III), and myoid cells. Epithelial reticular cells form a three-dimensional network which extends throughout all portions of the thymus. Type I and type II granulated cells can be distinguished from one another by various morphological criteria at the ultrastructural level, but only small differences in the composition of their inclusions can be demonstrated histochemically. Both types of granules are composed principally of a proteinaceous material containing an abundance of primary amino and guanidyl groups. In addition, most type I inclusions possess a lipid component that cannot be demonstrated in type II granules. Type III granulated cells possess very small cytoplasmic inclusions resembling those of gastroenteric endocrine cells. Myoid cells contain concentrically arranged myofibrils composed of sarcomeres. In favorably oriented material, small cysts can be identified whose walls are composed of mixtures of type I cells, type II cells, and epithelial reticular cells. Groups of degenerating epithelial cells form lamellated structures corresponding to Hassall's (thymic) corpuscles.
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  • 81
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    Journal of Morphology 160 (1979), S. 323-343 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Comparison of germ cells in male and female embryos of the arrhenotokous thrips, Haplothrips verbasci, yields the following observations: A mean of 11 cleavage energids enter the posterior pole plasm of the egg after the sixth cleavage division and apparently become pole cells when they take up polar granules in their cytoplasm. The cells proliferate asynchronously prior to and during anatrepsis to yield a mean of 36 germ cells in male embryos and 31 in females. Visible sexual differentiation of germ cells begins during germ band elongation and is completed shortly after the appearance of appendages. Female germ cells are larger than those of the males and may contain two nucleoli. The germ cells separate into two groups just before katatrepsis and mesodermal cells collect about these to form the primary epithelial sheaths of the gonads and the primordia of the gonoducts shortly after revolution is completed. Each gonad contains a mean of 13 germ cells in male embryos and 7 in females - a number that persists until mitosis resumes after hatching. During ketatrepsis, a mean of 11 germ cells in male embryos and 2.6 in females fail to be enclosed within the gonads, become dispersed in the yolk and perhaps transform into vitellophages.Germ cell development in H. verbasci embryos resembles similar events taking place in psocid embryos, providing additional evidence for a close phylogenetic relationship between Thysanoptera and Psocoptera.
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    Journal of Morphology 162 (1979), S. 77-91 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Diploid tadpoles of the discoglossid frog, Bombina orientalis, possess a distinctive rectangular network of epidermal melanophores. The ontogeny of this network was examined and utilized as a model for the comparison of tissue integrity and cellular interactions in diploid and haploid embryos.During the process of network formation in diploids, a variety of melano-phore-melanophore interactions was observed. These included temporary contacts between neighboring melanophore processes, deviations of processes toward neighboring melanophores, and lateral extensions between closely situated, parallel processes originating from different cell bodies. None of these intercellular interactions were seen in haploid embryos. Haploid melanophores displayed fewer cytoplasmic extensions, appeared to be randomly oriented, and failed to establish the ordered network seen in diploid embryos. It was also discovered that, in comparison with diploid tissues, relative densities of melanophores and epithelial cells were not uniformly regulated in haploid embryos.These findings are interpreted as indicating that haploid embryos possess fundamental cell and tissue defects, and that the “haploid syndrome” is likely based on more than one or a few defective physiological functions.
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  • 84
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    Notes: A β-keratin pattern, consisting of 30 Å filaments embedded in an amorphous matrix, is formed by fusion of membrane-bound packets with the 70 Å filaments of immature cells. This pattern occurs in the Oberhäutchen and the β-layer. When completely mature, these two components show no cell boundaries. It is suggested that this feature is associated with the process that leads to the separation of outer and inner epidermal generation. Filaments of 100-150 Å embedded in an amorphous matrix form the α-keratin pattern, which occurs in the α-layer only. The lacunar tissue is regarded as consisting of cells resembling immature α-cells, whereas mesos and clear layer show a keratin-like material consisting of 100-150 Å filaments without matrix. This is regarded as a modification of α-keratin. The cells of all components synthesizing α-keratin (α, mesos and clear layer) have the following features in common: (1) the plasma membrane is modified in that its inner leaflet is obscured by the deposition of a marginal layer, and (2) the cells have 0.06-0.1 μm mucous granules containing mucopolysaccharides, which release their content into the intercellular space.Protective and barrier functions of the epidermis are provided by the following features: (1) Oberhäutchen and β-layer merge during final maturation to a homogenous stratum of β-keratin without intercellular spaces. Their function seems to be mechanical protection. (2) The marginal layer of α-keratin containing cells, which decreases in thickness from without inwards, is highly resistant to physical and chemical influences. (3) Mesos granules contain phos-pholipid-lamellae, which are partly discharged into the intercellular space and partly remain within the mesos cells. These lipid lamellae are believed to contribute to the establishment of the permeability barrier. (4) The content of mucous granules may play a role in immunological processes. (5) Tight junctions seal off the intercellular space between the uppermost living cells of the epidermis and contribute to the permeability barrier.
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  • 85
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Somatic portions of gonads in two phanerozonian sea-stars, Ctenodiscus crispatus and Hippasteria phrygiana, were similar in all aspects of gross structure and histology seen previously in both forcipulate and spinulosan asteroids. For the first time, detailed ultrastructural observations have been made of cells and tissues that reveal several features believed to be of universal occurrence in the gonads of asteroids. These include flagellated-collar cells in the visceral peritoneum and other coelomically derived epithelia, muscular-flagellated-collar cells in the visceral peritoneum and genital coelomic (perihaemal) sinus, the digestion of collagen fibers by cells in the connective tissue layer, and the intimate relationship of the genital haemal sinus and the entire germinal epithelium.Structural and functional compartmentalization are discussed in relation to major activities of the gonad throughout the annual reproductive cycle. The distinctive ultrastructure and current generation of flagellated-collar cells found in the visceral peritoneum are analyzed relative to their role in nutrient transport to gonadal tissues. The single flagellum of each flagellated-collar cell beats in coordination with those on neighboring cells to produce extremely rapid, oriented currents of coelomic fluid. The form of beating in an individual flagellum is planar, and the resulting synchronized activity of many adjacent flagella is non-metachronal; both of these characteristic aspects of current production have, thus far, been encountered together only in the Echinodermata. Flagellated-collar cells are efficient in generating currents which mix contents of the coelomic fluid, and they can presumably supply themselves with nutrients. It is concluded that nutrients so obtained are generally not passed through the wall of the gonad to the germinal epithelium and, as a result, have little to do with nutrition of somatic and germinal cells of the germinal epithelium. Alternatively, well-developed genital portions of the haemal system of the sea-star are advanced as the major channels supplying nutrients to germinal epithelia during gametogenesis.
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  • 86
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    Journal of Morphology 162 (1979), S. 163-173 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Five different types of sense organs were found on the antennal flagellum of Homadaula anisocentra. These were (1) tactile hairs; (2) thick-walled chemoreceptors; (3) thin-walled chemoreceptors of several kinds; (4) styloconic chemoreceptors and (5) small chemoreceptor pegs in shallow depressions. No coeloconic sense organs were seen.
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  • 87
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    Journal of Morphology 162 (1979), S. 343-359 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology and carbohydrate histochemistry of ten teleostean intestines are compared. Although there is an absence of regional differentiation seen in higher vertebrates, specializations in some species occur in the form of intestinal swellings, pyloric ceca and recta, the latter separated by a valve. The intestinal lumen is lined by a simple columnar epithelium interspersed with goblet cells; multicellular intestinal glands are absent. Thick basement membranes seen in centrarchids and Perca flavescens closely resemble the stratum compactum found in the lamina propria of esocids. Granular cells, which vary in number from species to species, are often seen in the mucosa and submucosa but less frequently in the muscularis. In species with intestino-rectal valves, a rectum is easily defined by the abrupt appearance of lower mucosal folds, more goblet cells and a thicker muscularis. In the remaining species the above features appear gradually in the distal intestine. Goblet cells show species variations in localization of epithelial mucosubstances, which in broad terms are recognized as sulfomucins, sialomucins and neutral mucosubstances. In both proximal and distal intestines the majority of goblet cells contain sialomucin although small amounts of sulfomucin are also often present. In species without intestino-rectal valves, no changes in carbohydrates occur between proximal and distal intestines. The possible significance of the heterogeneous character of digestive tract mucosubstances is discussed.
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  • 88
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Differentiated Malpighian tubules of Periplaneta americana nymphs consist of four distinct regions. The distal, middle, and proximal regions are similar to the same regions in adult tubules. However, the transparent portion of the middle region was found to have ultrastructural characteristics different from those of the longer opaque segment of the middle region and the two other tubule regions. This newly distinguished region is called the lower middle region. Transitional zones, areas where cells show characteristics of two adjacent regions, are apparent between the distal and middle regions and between the middle and lower middle regions.The middle region of primary tubules undergoes an increase in autophagic activity and a modification of its basal infoldings and microvilli shortly before each molt. An increase in autophagic activity is also observed in the lower middle region near the time of molting.
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  • 89
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Four differentiated Malpighian tubules (primary tubules) extend from the junction of the midgut and hindgut in newly hatched Periplaneta americana. Secondary tubules begin to develop near the base of the primary tubules before hatching and successive nymphal molts. The newly initiated tubules undergo cell division and extensive elongation through the middle of the following intermolt period. During this time, the cells of the distal, middle, and lower middle tubule regions are surrounded by a cellular sheath, have few cytoplasmic processes extending along their basal surfaces, have a small or nonexistent lumen, and contain extremely dilated cisternae of endoplasmic reticulum. The cellular sheath differentiates into the muscle which coils around the mature tubule. Tubules which begin development toward the end of one intermolt period begin to undergo cytodifferentiation toward the end of the next intermolt period. By the middle of an additional intermolt period, the basal infoldings and microvilli of cells in the distal, middle, and lower middle regions have the conformations typical for those regions in differentiated tubules; granular concretions and stellate cells are present within the middle region of the tubule.
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  • 90
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The afferent and efferent components of the facial nerve were traced within the brain stem of Rana catesbeiana, using three different neuroanatomical techniques. Primary afferent fibers could be traced to the spinal tract of trigeminal nerve and to fasciculus solitarius as far caudally as the first or second spinal segment, using silver degeneration methods. Cobalt filling of the entire nerve showed the same distribution of afferent fibers, as well as the filling of the cells within the mesencephalic nucleus of trigeminal, indicating the origin of a proprioceptive component of the facial nerve. Cobalt iontophoresis and horseradish peroxidase experiments showed that the motor nucleus of the facial nerve was located just ventral to the fourth ventricle, and caudal to the motor nucleus of trigeminal. The distribution of afferent fibers to fasciculus solitarius and the spinal tract of trigeminal is similar in some respects to the distribution of afferent fibers from the trigeminal and vagal nerves in the bullfrog. The afferent fibers from the three cranial nerves are found as far caudally in the brain stem as the second spinal segment.
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  • 91
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Single-element and/or rosette strain gages were bonded to mandibular cortical bone in Galago crassicaudatus and Macaca fascicularis. Five galago and eleven macaque bone strain experiments were performed and analyzed. In vivo bone strain was recorded from the lateral surface of the mandibular corpus below the postcanine tooth row during transducer biting and during mastication and ingestion of food objects.In macaques and galagos, the mandibular corpus on the balancing side is primarily bent in the sagittal plane during mastication and is both twisted about its long axis and bent in the sagittal plane during transducer biting. On the working side, it is primarily twisted about its long axis and directly sheared perpendicular to its long axis, and portions of it are bent in the sagittal plane during mastication and molar transducer biting. In macaques, the mandibular corpus on each side is primarily bent in the sagittal plane and twisted during incisal transducer biting and ingestion of food objects, and it is transversely bent and slightly twisted during jaw opening. Since galagos usually refused to bite the transducer or food objects with their incisors, an adequate characterization of mandibular stress patterns during these behaviors was not possible. In galagos the mandibular corpus experiences very little transverse bending stress during jaw opening, perhaps in part due to its unfused mandibular symphysis.Marked differences in the patterns of mandibular bone strain were present between galagos and macaques during the masticatory power stroke and during transducer biting. Galagos consistently had much more strain on the working side of the mandibular corpus than on the balancing side. These experiments support the hypothesis that galagos, in contrast to macaques, employ a larger amount of working-side muscle force relative to the balancing-side muscle force during unilateral biting and mastication, and that the fused mandibular symphysis is an adaption to use a maximal amount of balancing-side muscle force during unilateral biting and mastication.These experiments also demonstrate the effects that rosette position, bite force magnitudes, and types of food eaten have on recorded mandibular strain patterns.
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  • 92
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Although a number of recent studies describe the facilitation of limb regeneration by electrical and other forms of stimulation, little is known of innate regenerative capacity in the mammalian limb. The present report describes spontaneous regenerative responses following subtotal forelimb amputation in the young white rat. In one group of animals the forelimb was amputated through the lower humerus and the skin sutured closed. In a second group, adjacent muscle tissue still attached to bone at its origin(s) was interposed between the cut surface of the humerus and the skin. Among animals of the first group (skin closure only) bone growth and limb regenerative responses were generally not observed. Animals of the second group displayed significant elaborations of cartilage and bone at the limb terminus. The appearance and subsequent modification of these tissues suggest that some capacity for limb regeneration exists innately in the young rat and can be more readily evoked than has been recognized heretofore. It is concluded that extant and forthcoming reports of electrically stimulated skeletal tissue growth, repair and regeneration among eutherial mammals should be examined to determine whether reported responses to stimulation represent advances beyond what might be expected from innate replacement processes alone.
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  • 93
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Five regions are recognized in the accessory glands of the Mediterranean flour moth, Anagasta kuehniella (Zeller), on the basis of cellular morphology and aggregates of secretory material in the lumen. Some variation is found in each of the posterior four regions, especially the third one. In the most anterior region (region 1) the epithelium is composed of a single type of cell, while in each of the other regions there are two classes of cells. The cells of region 1 and one class in each of the other four regions are fairly typical exocrine cells with extensive rough endoplasmic reticula. Secretion is primarily via Golgi-derived vesicles. Apocrine secretion in the form of sloughing off of the apical cytoplasm probably also occurs in all regions but is most prominent in the posterior two regions. One class of cells is very similar in morphology in each of the posterior four regions though their secretory products form characteristic aggregates in the lumen. The second class of cells (foliate cells) occurring in the posterior four segments is most notably characterized by elongate apical projections that extend out into the lumen. The apical projections contain large quantities of glycogen, some microtubules, and, in some cases, many minute mitochondria. The membrane content of the projections is also very high. In the anterior regions, the membranes are mostly fused in pairs and typically form multilayered whorls. Fusion and whorl formation decrease in the posterior regions. The cytoplasm of the foliate cells has a high organelle content including many lysosomes and mitochondria. The latter exhibit considerable polymorphism, with particular forms occurring in the different regions of the glands. The apical projections of the foliate cells are detached during copulation, presumably as the result of nervous stimulation, and become a part of the ejaculate. Replenishment of all secretory material, including the apical projections, occurs after copulation.
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  • 94
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    Journal of Morphology 159 (1979), S. 393-425 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Branchial food traps are regions of specialized secretory tissue in the tadpole pharynx, where suspended food particles are trapped in mucus.Light and scanning electron microscopy were used to study branchial food traps from larvae of ten anuran families (36 species). Most anuran larvae from “advanced” (suborder Neobatrachia) families (e.g., Hylidae, Ranidae, Bufonidae) have distinct secretory pits at the posterior margins of the branchial food traps and secretory ridges elsewhere on these surfaces. The apices of columnar PAS-positive, secretory cells are exposed on the floors of the secretory pits or in rows at the tops of the secretory ridges (secretory zone).Tadpoles from most “archaic” (suborder Archaeobatrachia) families (Ascaphidae, Discoglossidae and Pelobatidae) either lack secretory pits, or have them poorly defined. They also lack secretory ridges but have columnar, mucus-secreting cells whose apices are exposed in a seemingly random fashion in the branchial food traps. Rhinophrynus (Archaeobatrachia: Rhinophrynidae) has secretory ridges, but the apices of secretory cells are not arranged in rows at the tops of the ridges; instead they erupt singly or in small clusters on the epithelial surface, in a pattern similar to that in Ascaphus, the discoglossids and the pelobatids. It is proposed that the generalized condition for the branchial food trap mucosa is one where the apices of secretory cells are exposed haphazardly on a flat epithelium and the derived condition is one where the surface is organized into ridges. The morphology of the branchial food traps in Rhinophrynus suggests that, phylogenetically, ridges preceded the coalescing of secretory cell apices into distinct rows.Pipidae and Microhylidae have unique patterns in the gross and microanatomy of their branchial food traps specific to their families.Branchial food trap morphology relates to diets of tadpoles as well as to taxonomy. Obligate macrophagous (e.g., carnivorous) tadpoles, irrespective of family, tend to have reduced branchial food traps, regularly lack secretory ridges and, in extreme cases, lack columnar mucus-secreting cells. Obligate microphagous forms (midwater suspension feeding of Xenopus, microhylids and Agalychnis), have straight parallel secretory ridges with narrow secretory zones and shallow troughs between the ridges.Secretory ridges may help to form mucus strands in which food particles are trapped, but they are not essential for planktonic entrapment. The hydrodynamic implications of the various topographic patterns remain unclear.
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  • 95
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979) 
    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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  • 96
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This investigation was undertaken to examine the observations of Becker ('72) pertaining to the electrical facilitation of partial limb regenerative responses by means of Ag-Pt wire couples applied to the limb stumps of young, forelimb-amputated white rats. Additionally, in order to examine the possible role of mechanical effects of such device implantations, we have employed uncoupled devices delivering no current or potential difference. In the present experiments, in response to coupled device implantation, cartilage and bone were actively formed in the vicinity of the Pt electrode tip. These tissues contributed to the lengthwise extension of the limb and to the partial restoration of the distal humeral extremity. In limbs bearing the uncoupled electrical devices, qualitatively similar responses were noted, but osteogenesis was diminished in extent compared to that seen in limbs bearing the active or coupled devices. It is therefore necessary to consider the role of mechanical factors in the elicitation of the observed regenerative responses. Myogenesis was enhanced in electrically stimulated limbs, but not in those rats bearing uncoupled devices.
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  • 97
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 1-5 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Tactile hairs, small chemoreceptor pegs, thick-walled chemoreceptors, thin-walled chemoreceptors of several types, coeloconic sense organs and campaniform sense organs are present on the flagellum of a stonefly, Allocapnia recta (Claassen).
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  • 98
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    Journal of Morphology 160 (1979), S. 7-15 
    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 contact chemoreceptors in the cibariopharyngeal pump of the moth Trichoplusia ni (Lepidoptera: Noctuidae) is described. Two types of receptors designated A and B are located on the floor of the pump. Two groups of 9-12 A receptors are located in the anterior part of the pump, and two groups of two B receptors are in the posterior part of the pump. Five sensory dendrites extend to the tip of each A receptor and four to each B receptors. Available evidence indicates that these receptors are contact chemoreceptors and do not serve as mechanoreceptors. The receptors are compared to those of other insects.
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  • 99
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    Journal of Morphology 160 (1979), S. 17-31 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The minimum number of secretion products used by the spiders Araneus trifolium and Argiope trifasciata to construct their orb webs has been established by selective enzyme digestion and histochemical staining, as well as differential isotope localization in these webs. Three fiber types are present in the webs: (a) a major fiber found throughout the web, (b) a minor fiber found only in radial threads, and (c) the core fibers of the sticky spiral thread. Three nonfibrous secretions are found on these fibers. These include a water soluble viscid coating of the sticky spiral and two adhesives which fasten the threads of the web together; one found only at junctions of sticky spiral and radial threads and the other at all other thread connections. The possible glandular sources of these secretions are discussed.
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  • 100
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    Journal of Morphology 160 (1979), S. 33-73 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The most complete account of the hind leg muscles of the kiwi was published a century ago by Sir Richard Owen, in his seventy-fifth year. This extensively-cited work has several omissions and errors, and while certain of these were corrected by subsequent authors, sufficient uncertainty remains to warrant a reinvestigation. In the present study a detailed description of the hind leg musculature is given, based upon dissections of two frozen specimens. An indication of the possible function of each muscle is given by assessing its size, action, and fiber-arrangement, together with tentative data on the relative abundance of twitch and tonus fibers.The correlation between surface features of bones and muscle attachments is investigated with a view to interpreting palaeontological material. Although the limb and pelvic bones are marked by numerous features which suggest muscle attachments, relatively few can be positively identified with specific muscles. Only 23% of the muscle origins and insertions can be identified, and, with three possible exceptions, no indication of relative size is given by the scars. The possibility of being able to reconstruct the musculature of the kiwi from its skeletal anatomy, much less that of its extinct relatives, is remote.
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