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  • Life and Medical Sciences  (2,512)
  • Aircraft Propulsion and Power
  • 1975-1979  (1,862)
  • 1950-1954  (691)
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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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  • 29
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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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    Developmental Genetics 1 (1979) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
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  • 34
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    Developmental Genetics 1 (1979), S. 1-1 
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    Keywords: Life and Medical Sciences ; Genetics
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  • 35
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    Developmental Genetics 1 (1979), S. 3-12 
    ISSN: 0192-253X
    Keywords: cell culture ; Nicotiana ; epigenetic variation ; gel electrophoresis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Polypeptides solubilized from established normal and variant cell lines of Nicotiana tabacum L cv “Wisconsin 38” have been analyzed by one-dimensional and two-dimensional gel electrophoresis. There was little variability observed in the polypeptide profile in an established cell line; polypeptides present in different clonal lines of cells, all derived from an initial established cell culture, were very similar, if not identical. However, a large fraction of the observed polypeptides present in cytokinin-habituated cell lines (up to 3.8% of the total polypeptides analyzed by two-dimensional gel electrophoresis) were different from those found in the cytokinin-requiring cells from which they were selected. The habituated nature of the selected cell lines was demonstrated to be epigenetic; tissue cultures that were reisolated from plantlets regenerated from habituated cell lines did require cytokinin. Further observations demonstrate: (1) that epigenetic events that alter a cellular phenotype change the expression of a relatively large number of polypeptides, (2) that a single epigenetic phenotype may be the result of any one of a number of possible patterns of gene expression, and (3) that epigenetic events are not random events.
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    Developmental Genetics 1 (1979), S. 13-20 
    ISSN: 0192-253X
    Keywords: morphogenesis ; cAMP ; ammonia ; Dictyostelium discoideum ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Two compounds, ammonia (NH3) and 3′5′ cyclic AMP (cAMP) act as specific morphogens in regulating the development of Dictyostelium discoideum [1-11]. A previous study [12] demonstrated that NH3 at concentrations that affect the course of morphogenesis completely inhibits the extracellular release of cAMP by aggregation competent cells incubated in shaken suspension. The present study extends this finding in two respects: 1Exposure of aggregation competent cells to NH3 (supplied as ammonium carbonate) is followed within a few minutes by the complete disappearance of intracellular cAMP. Subsequent removal of NH3 is followed by a rapid, complete restoration of the level. Neither the disappearance nor the reappearance is affected by the presence of cycloheximide, an inhibitor of protein synthesis.2In a mutant strain of D discoideum, greatly increased sensitivity to NH3 as a regulator of morphogenesis is coupled with a correspondingly increased sensitivity to NH3 as an inhibitor of cAMP accumulation.These results are consistent with a recently proposed [13, 14] model of morphogenetic regulation that is based on the supposition that NH3, by inhibiting cAMP production, restricts cAMP accumulation to specified constrained areas within the developing multicellular aggregate and thereby dictates the course of morphogenesis and cytodifferentiation.
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    Developmental Genetics 1 (1979), S. 47-60 
    ISSN: 0192-253X
    Keywords: developmental mutants of Physarum ; apogamic mutants ; the amoebal-plasmodial transition ; myxomycete genetics ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the heterothallic myxomycete Physarum polycephalum, uninucleate amoebae normally differentiate into syncytial plasmodia following heterotypic mating. In order to study the genetic control of this developmental process, mutations affecting the amoebal-plasmodial transition have been sought. Numerous mutants characterized by self-fertility have been isolated. The use of alkylating mutagens increases the mutant frequency over the spontaneous level but does not alter the mutant spectrum. Three spontaneous and 14 induced mutants have been analyzed genetically. In each, the mutation appears to be linked to the mating type locus. In three randomly selected mutants, the nuclear DNA content is the same in amoebae and plasmodia, indicating that amoebal syngamy does not precede plasmodium development in these strains. These results indicate that a highly specific type of mutational event, occurring close to or within the mating type locus, can abolish the requirement for syngamy normally associated with plasmodial differentiation. These mutations help define a genomic region regulating the switch from amoebal to plasmodial growth.
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    Developmental Genetics 1 (1979), S. 21-46 
    ISSN: 0192-253X
    Keywords: Paramecium tetraurelia ; trichocysts ; nuclear differentiation ; cellular differentiation ; cytoplasmic inheritance ; developmental genetics ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Paramecium tetraurelia, stock d113, although completely homozygous, produces two kinds of genomically identical clones: N (nondischarge) clones incapable of trichocyst exocytosis (discharge) from intact cells in response to picric acid; and D (discharge) clones that do respond. These alternatives are irreversibly determined (at 27°C) during a determination sensitive period the first day after fertilization (autogamy, conjugation, or cytogamy): D parents are always determined to produce D progeny; N parents produce mostly N progeny if kept in exhausted medium, but mostly D progeny if kept in bacterized nutrient medium, throughout the sensitive period. If connecting bridges between mates persist long after the time for pair separation, the N member of N×D conjugant and cytogamous pairs produces D progeny even if exposed to exhausted medium throughout the sensitive period, thus indicating the presence in D mates of a D-determining cytoplasmic factor, δ, which overrides effects of external conditions. N and D determinations are brought about on newly developing somatic nuclei (macronuclear anlagen). After macronuclear development has been completed, determination is irreversible in it and its descendant macronuclei. M (mixed) clones produce N, D, and partial D cells; within these clones, diverse subclones can be selected. Crosses of d113 (N)×standard wild stock 51 (D) yield no segregation in F2, indicating no genomic difference between d113 (N) and wild type (D), δ may be a genic product regulating its own production. This results in “cytoplasmic inheritance” of D vs N in crosses of D×N followed by exhausted medium during the sensitive period. As with the only other well-analyzed comparable example, mating types, neither a genetic nor an epigenetic interpretation has yet been excluded for this system of developmental differentiation.
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    Developmental Genetics 1 (1979), S. 61-68 
    ISSN: 0192-253X
    Keywords: pink-eyed dilution locus ; spermatozoa ; sialic acid residues ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Abnormal spermiogenesis in sterile pink-eyed dilution mutants results in spermatozoa with bizarre sperm heads. The spermatozoa of normal mice bind colloidal iron hydroxide (CIH) along the length of the tail, yet the spermatozoa of pink-eyed sterile mice show a great reduction in ability to bind CIH. This implies a loss of negative surface charges. The group(s) responsible for the charges are sensitive to methylation but resistant to neuraminidase treatment, even after deacetylation with alkaline treatment. The membrane components containing the negatively charged groups may be neuraminidase-resistant forms of gangliosides.
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    Developmental Genetics 1 (1979), S. 69-76 
    ISSN: 0192-253X
    Keywords: oocytes ; cleavage stage embryos ; major histocompatibility complex ; immunofluorescence ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mouse oocytes at the dictyate and metaphase II stages as well as fertilized eggs have been studied by indirect immunofluorescence for the expression of H-2 histocompatibility antigens on surface membranes. Serologically specific reactivity to H-2 antibody was observed as patchy fluorescence distributed over the surface of the oocyte membrane. In contrast, one-cell zygotes exhibited variable reactivity, and early two-cell stages were negative. Absorption studies confirmed the serologic specificity of the reactivity on oocytes, which could be shown to be due to H-2 antibody. The results suggest that fertilization results in altered expression of major histocompatibility complex surface antigens, and confirms earlier studies that cleavage stage mouse embryos are not reactive with H-2 antibody.
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    Developmental Genetics 1 (1979), S. 77-95 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; pupae ; heat shock ; protein synthesis ; phenocopies ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Pupae of Drosophila melanogaster were heat-shocked under conditions required to induce phenocopies in more than 90% of the flies that subsequently emerge. The effects of these treatments on protein synthesis in two tissues (thoracic epithelium and brain) were followed for several hours after the heat treatments. Results from pulse-labeling and protein separations on sodium dodecylsulfate (SDS) acrylamide gels showed a virtually complete cessation of protein synthesis immediately after the shock, followed by a noncoordinate resumption of the starting pattern. Similar experiments following double heat shocks demonstrated a more rapid resumption of synthesis of heat shock proteins after two successive heat treatments than after a single one.
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    Developmental Genetics 1 (1979) 
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    Keywords: Life and Medical Sciences ; Genetics
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    Developmental Genetics 1 (1979), S. 97-107 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; maternal effect ; 6-phosphogluconate dehydrogenase ; glucose-6-phosphate dehydrogenase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We studied the maternal effect for two enzymes of the pentose cycle, 6-phosphogluconate dehydrogenase (6PGD) and glucose-6-phosphate dehydrogenase (G6PD), using a genetic system based on the interaction of Pgd- and Zw- alleles, which inactivate 6PGD and G6PD, respectively. The presence and formation of the enzymes was investigated in those individuals that had not received the corresponding genes from the mother. We revealed maternal forms of the enzymes, detectable up to the pupal stage. The activities of “maternal” 6PGD and G6PD per individual increased 20-fold to 30-fold from the egg stage to the 3rd larval instar even in the absence of normal Pgd and Zw genes. Immunologic studies have shown that the increase in 6PGD activity is due to an accumulation of the maternal form of the enzyme molecules. We revealed a hybrid isozyme resulting from an aggregation of the subunits of isozymes controlled by the genes of the mother and embryo itself. These results indicate that the maternal effect in the case of 6PGD is due to a long-lived stable mRNA transmitted with the egg cytoplasm and translated during the development of Drosophila melanogaster.
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    Developmental Genetics 1 (1979), S. 109-121 
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; alkaline phosphatase mutant ; linkage analysis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Alkaline phosphatase is one of several enzymes that accumulate in a temporally regulated sequence during the development of Dictyostelium discoideum. These enzymes can be used to monitor specific gene expression; moreover, isolation and analysis of mutations in the structural gene(s) can serve to indicate some of the essential steps in programmed synthesis and morphogenesis. A mutation (alpA) which affects the activity and substrate affinity of alkaline phosphatase was isolated in D discoideum using a procedure for screening large numbers of clones. Alkaline phosphatase activity at all stages of vegetative growth and development was altered by the mutation. Several physical properties of the enzyme from growing cells and developed cells were compared and found to be indistinguishable. It is likely that a single enzyme is responsible for the majority of alkaline phosphatase activity in growth and development. The mutation is coexpressed in diploids heterozygous for alpA and maps to linkage group III. One of the haploid segregants isolated from these diploids carries convenient markers on each of the six defined linkage groups and can be used for linkage analysis of other genetic loci.
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    Developmental Genetics 1 (1979), S. 123-132 
    ISSN: 0192-253X
    Keywords: nonrandom X-inactivation ; maternal X chromosome expression ; mouse ; extraembryonic membrane ; X chromosome ; PGK-1 ; chorionic ectoderm ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An electrophoretic variant of the X-linked enzyme phosphoglycerate kinase (PGK-1) has been used to study regulation of X chromosome expression in the diploid derivatives of the trophectoderm at 8-8.5 days post coitum in the mouse. These derivatives included the chorionic ectoderm and the polar trophoblast. The biochemical analysis suggests that only the maternally derived X chromosome (Xm) is expressed in the diploid trophectoderm derivatives. Cell selection and maternal tissue contamination were ruled out as possible causes of the observed Xm expression. From these and other results, we conclude that all derivatives of the trophectoderm, along with the primitive endoderm, express only Xm, whereas derivatives of the primitive ectoderm show random X chromosome expression.
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    Developmental Genetics 1 (1979), S. 151-165 
    ISSN: 0192-253X
    Keywords: sea urchin embryo ; hnRNA ; mRNA ; 5′ terminal cap ; turnover ; synthesis rate ; methylation ; developmental changes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The relationship between heterogeneous nuclear RNA (hnRNA) and messenger RNA (mRNA) synthesis has been studied as a function of the development of the sea urchin embryo through the use of methyl incorporation. Several parameters in the metabolism of capped hnRNA and mRNA of early blastula and late gastrula stages have been investigated by measuring the kinetics of transfer of methyl groups from S-adenosylmethionine to the 5′ cap structures in nuclear and cytoplasmic RNA: 1The rate constants for the decay of hnRNA caps and the synthesis of mRNA caps are equal to within experimental error. This equality indicates a flux of precursor hnRNA caps to mRNA caps with a very high degree of conservation of the hnRNA caps. This conservation holds for each embryonic stage.2From literature data on the labeling kinetics of GTP and mRNA, we have calculated the decay constant of a putative mRNA precursor component of hnRNA. The value of this constant is very close to that for the decay constant of hnRNA caps. Hence, all hnRNA caps and some portion of their associated hnRNA sequences behave kinetically as the pre-mRNA fraction. This kinetically ascribed pre-mRNA comprises approximately 30% of the hnRNA mass.3The part of the hnRNA which does not serve as precursor to mRNA turns over at least twice as rapidly as the pre-mRNA fraction.4During development from early blastula to late gastrula, the rate of hnRNA cap synthesis drops from 2 × 103 molecules/min/cell to half of this value. This decline is parallel to the decline in total hnRNA synthesis and thereby confirms the constant degree of capping of hnRNA, as previously reported. We infer that the pre-mRNA fraction of hnRNA remains nearly constant during this developmental period.
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    Developmental Genetics 1 (1979), S. 167-179 
    ISSN: 0192-253X
    Keywords: agouti locus ; hair pigment patterns ; melanocyte metabolism ; tissue microenvironment ; eumelanin ; phaeomelanin ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: This study was conducted to assess microenvironmental variability within integumental tissue of genetically identical mice with respect to a specific cellular response: cyclic synthesis of yellow and black pigment by hair bulb melanocytes. Crosses were performed within and between inbred strains of mice that were isogenic with the exception of a single gene substitution at the agouti locus. Agouti locus genes included the Avy, Aw, A, atd, at, ax, am, and a alleles. The pigment patterns of dorsal, flank, and ventral hairs of the first and third hair generations and of hairs growing in special integumentary areas such as the pinna, tail, and hind foot were studied. It was found that the amount of yellow pigment synthesized by hair bulb melanocytes within genetically identical mice is both agedependent and conditioned by the integumentary environment. Furthermore, the special integumentary regions produce hairs with a variety of pigment patterns in which the distribution and relative amounts of black and yellow pigments do not necessarily conform to dominance relationships expected among agouti locus alleles as judged by their effects on the pigmentation of the dorsal pelage. We conclude that within genetically uniform integumental tissues, microenvironmental differences occur and are reflected as alterations in the metabolic pattern of differentiated cells.
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    Developmental Genetics 1 (1979), S. 133-150 
    ISSN: 0192-253X
    Keywords: Naegleria gruberi ; flagellum number ; heat shock ; protein synthesis ; RNA synthesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The induction of multiple flagella by a heat shock was used to examine the role of RNA and protein synthesis in the regulation of the number of flagella produced during the differentiation of the amebo-flagellate Naegleria gruberi. Control cells differentiating at 25.0°C produce an average of 2.1 flagella per flagellate (f/F), whereas cells exposed to 38.2°C from 35 minutes until 72 minutes after initiation produce an average of approximately 5 f/F. Heat shock was found to prevent completion of the RNA synthesis essential for flagellum formation, even though both RNA and protein synthesis continued at 38.2°C. A delay of two minutes for every one minute of heat shock was seen in both the formation of flagella (T50) and the completion of essential RNA synthesis for heat shocks of one to ten minutes applied beginning 35 minutes after initiation. Times at 38.2°C of ten minutes to 45 minutes produced a delay of approximately 0.6 minutes for each minute of heat shock, whereas shocks longer than 47 minutes prevented flagellum formation. The times from completion of RNA synthesis until completion of protein synthesis or flagella formation were found to be approximately 15 minutes and approximately 32 minutes, respectively. This was true in control cells as well as in cells heat shocked for up to 45 minutes. The fact that heat shock delayed completion of RNA synthesis without affecting the time for completion of protein synthesis or flagella formation suggests that heat shock acts at some step related to the completion of transcription. Short heat shocks, 30 seconds to five minutes, were observed to prevent flagellum formation in cells that had completed RNA synthesis if additional RNA synthesis was inhibited. In contrast, short heat shocks had little effect on cells that had completed protein synthesis, even if additional protein synthesis was inhibited. Two alternative hypotheses for the mechanism of heat shock delay of transcription are discussed. One hypothesis involves a direct effect of high temperature on transcription, and the other postulates a temperature-sensitive protein necessary for flagellum formation.
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    Developmental Genetics 1 (1979), S. 181-192 
    ISSN: 0192-253X
    Keywords: drosophila ; gene regulation ; heat shock ; protection phenocopies ; survival ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Mild heat treatments applied to whole animals or cell cultures of Drosophila prior to lethal heat shocks result in increased survival and protection against phenocopy induction. The optimal condition for the preliminary mild heat treatment is that which induces the synthesis of heat-shock proteins but does not turn off the protein synthesis that is in progress. Recovery of protein synthesis but not RNA synthesis following a drastic heat shock is much enhanced by the pretreatments. The results suggest that the protection for survival and against phenocopy induction is due to storage of messenger RNA.
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    Developmental Genetics 1 (1979), S. 193-193 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
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    Developmental Genetics 1 (1979) 
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    Keywords: Life and Medical Sciences ; Genetics
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    Developmental Genetics 1 (1979), S. 195-204 
    ISSN: 0192-253X
    Keywords: apterous mutant ; Drosophila melanogaster ; juvenile hormone ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The apterous (ap) mutant in Drosophila melanogaster exhibits phenotypes of wing deficiency, precocious adult death, and nonvitellogenic oocyte development. The latter phenotype previously has been shown to result from juvenile hormone (JH) deficiency in the adult stage. To explore the relationship between the hormone deficiency and the other phenotypes, the expression of each phenotype was measured in five alleles of ap (including a new, chemically-induced allele, ap77f) as wing length, survival five days after eclosion, and initiation and progress of vitellogenic oocyte development. No correlation could be found between severity of wing phenotype and that of precocious adult death or nonvitellogenesis. However, the latter phenotypes were correlated in both ap homozygotes and allelic heterozygotes, since adults that survive have wild-type vitellogenesis, and those fated for precocious death fail to develop vitellogenic oocytes. These results indicate that no relationship exists between wing and JH deficiencies, but that precocious adult death is related to hormone deficiency  -  probably through pleiotropy, rather than through causality.
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    Developmental Genetics 1 (1979), S. 229-240 
    ISSN: 0192-253X
    Keywords: aldehyde oxidase ; alcohol dehydrogenase ; Hawaiian Drosophila ; interspecific hybridization ; regulatory genes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Drosophila heteroneura and D differens are closely related, interfertile species of the Hawaiian picture-winged group. They display marked qualitative and quantitative differences in the pattern of expression of alcohol dehydrogenase (ADH) and an aldehyde oxidase (AO-1). These presumptive regulatory differences are revealed by comparisons of the relative levels of these enzymes in various tissues in larvae and adults. In hybrids produced between parents carrying different electrophoretic alleles at the structural loci for these two enzymes, each allele is expressed according to the developmental program characteristic of the parent from which it was derived. This result indicates control of the differences in pattern of expression by one or more cis-acting sites associated with each structural locus. The distribution of activity among all the three forms of these dimeric enzymes produced in hybrids indicates that the pattern differences reflect differential accumulation of enzyme molecules, not altered catalytic properties. As expected, the regulatory differences segregate with the electrophoretic markers in backcrosses.
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    Developmental Genetics 1 (1979), S. 219-228 
    ISSN: 0192-253X
    Keywords: mouse ; lethal albino deletions ; Cattanach's translocation ; X-inactivation ; cell mosaicism ; genetic rescue ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Deletions of gene sequences in chromosome 7 of the mouse are known to interfere with biochemical and cellular development differentiation with lethal effects in homozygotes. The presence of the corresponding wild-type alleles in Cattanach's translocation (chromosomes 7 to X) is able to “rescue” potentially lethal females if they are made heterozygous for the translocation-carrying X chromosome. This holds true for those chromosome 7 deletions with perinatally lethal effects, whereas “rescue” is not readily accomplished with the deletions that cause early embryonic lethality. Females homozygous for the relevant deletion sequences and heterozygous for the translocation-carrying X chromosome are mosaics of two cell types: those in which the wild-type alleles included in the translocated piece complement the depleted sequences, resulting in a normal cellular phenotype, and those with the ordinary X chromosome expressing the lethal phenotype. The developmental interactions between the two cell types and their role in the mechanisms responsible for survival of females homozygous for lethal deletions are discussed. The failure of “rescue” of embryonic lethals reflects as yet unknown temporal and functional aspects of X-inactivation early embryogenesis.
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    Developmental Genetics 1 (1979), S. 205-218 
    ISSN: 0192-253X
    Keywords: Tetrahymena thermophila ; genomic exclusion ; micronucleus ; macronucieus ; nucleocytoplasmic interactions ; developmental cytogenetics ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Genomic exclusion is an aberrant form of conjugation of Tetrahymena thermophila in which the genome of a defective conjugant is excluded from the genotype of the exconjugant progeny. This paper is concerned with the cytogenetic and nucleocytoplasmic events of genomic exclusion in senescent clones A*III and C*. In crosses between A*III or C* and strain B, functional, haploid gametic nuclei are formed only in the strain B cell. In some instances one of the gametic nuclei divides prior to transfer of the migratory gametic nucleus, and both products then undergo DNA synthesis. Two alternative cytogenetic pathways are followed after transfer of the migratory nucleus. In the first, the conjugants separate without further micronuclear divisions. This pathway was most common in A*III genomic exclusion. In exconjugants the former gametic nuclei undergo both DNA synthesis and (presumably) intranuclear separation of centromeres to restore micronuclear diploidy. The old macronucleus of each exconjugant is retained without autolysis. This class of exconjugant survives and contributes genes to future sexual progeny. In the second cytogenetic pathway the gametic nuclei divide and macronuclear anlagen are formed, as in normal conjugation. This pathway was more common in C* genomic exclusion. The initial DNA content of the anlagen ranges from haploid to diploid. Following two to three rounds of DNA synthesis, further macronuclear development ceases and the anlagen appear to undergo autolysis. The old macronucleus condenses and also undergoes autolysis, as in normal conjugation. Except for rare C* exconjugants, in which macronuclear development is completed, anlagen-bearing genomic exclusion exconjugants die. Death may be caused by aneuploidy, errors in the timing or receptivity to signals for autolysis, or the inability of anlagen-bearing exconjugants to feed. Anlagenbearing conjugants are frequently abnormal with respect to the number of anlagen and micronuclei. Most of the anomalies can be explained by postulating errors in the timing of both developmental signals and nuclear divisions. Rare conjugants in which gametic nuclei divide but do not give rise to macronuclear anlagen are also observed. In these instances, the old macronuclei condense and undergo autolysis. Destruction of the old macronucleus therefore is independent of the presence of macronuclear anlagen and requires cell pairing in order to be initiated.
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    Developmental Genetics 1 (1979), S. 241-246 
    ISSN: 0192-253X
    Keywords: β-glucosidase mutants ; dictyostelium ; developmental regulation ; linkage group VI ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Seven mutations affecting β-glucosidase activity in Dictyostelium discoideum were found to be non-complementing, recessive to the wild-type allele, and to occur in the gene locus, gluA. This gene, which is likely to be the structural gene for β-glucosidase, since a mutation in it gives rise to thermolabile activity and other mutations in it result in no measurable activity, was mapped to linkage group VI. The expression of the β-glucosidase gene is regulated such that the enzyme is synthesized during the growth phase and during culmination, but not during the first 18 hours following the initiation of development. If expression of the structural gene required the function of a positive regulatory protein coded for by a gene as mutable as the gluA gene, there was greater than 99% chance one of the mutations of this series would have affected the regulatory locus. The absence of a second complementing locus for β-glucosidase suggests that this enzyme is regulated by other means.
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    Developmental Genetics 1 (1979) 
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    Keywords: Life and Medical Sciences ; Genetics
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    Developmental Genetics 1 (1979), S. 247-256 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; female sterile mutation ; pole cell transplantation ; abnormal follicle cell function ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Homozygous Drosophila females bearing the ocelliless mutation are sterile and produce oocytes with abnormal chorions. It has been possible to determine in which tissues these defects reside by generating ovarian chimeras. Pole cells from ocelliless female embryos can give rise to functional oocytes surrounded by normal chorions when placed in a wild-type environment. Conversely, when wild-type pole cells are placed in homozygous ocelliless females, the oocytes that form from them have abnormal chorions and never give rise to progeny. Thus the chorion defect and sterility of the ocelliless mutation are not germ-line autonomous. Homozygous ocelliless ovaries will attach to the uterus when placed in a wild-type third instar larva, but few eggs are ever laid, and the chorions of stage 14 oocytes remain ocelliless in morphology. Wild-type ovaries continue to produce oocytes with normal chorion morphology when placed into ocelliless hosts, indicating that the ocelliless chorion defect is ovary autonomous. Thus the chorion defect of the ocelliless mutation resides in the ovarian somatic tissue, presumably the follicle cells.
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    Developmental Genetics 1 (1979), S. 257-269 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A protein which has been shown to inhibit catalase in vitro appears to vary inversely with catalase activity in the maize scutellum during early sporophytic development when assayed using a catalase inhibition assay. This result suggested that the inhibitor protein may play a direct role in regulating catalase activity during this time period.Four experimental approaches were used to evaluate this putative regulatory role, including immunological quantitation of individual catalase isozymes during germination using rocket immunoelectrophoresis, perturbation of normal catalase expression with hydrogen peroxide or allylisopropylacetamide (AIA), examination of a mutant line with an altered catalase developmental program, and direct radioimmunoassay of the inhibitor protein during germination. The results of these experiments indicate that the quantitative changes in catalase activity during development are not mainly due to changes in the expression of the catalase inhibitor. Other possible roles of this protein in catalase regulation are discussed.
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    Developmental Genetics 1 (1979), S. 271-294 
    ISSN: 0192-253X
    Keywords: pigment mutants ; axolotl ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Mexican axolotl (Ambystoma mexicanum) provides a well-defined set of color genes which are useful for various types of analyses. These include the a (albino), m (melanoid), ax (axanthic), and d (white) genes. In addition, various combinations of these genes and a number of as yet undescribed mutants also exist. Three of these mutants (a, ax, and m) have defects associated with specific neural-crest-derived pigment cell types. The fourth mutant (d) appears to provide an unsuitable environment for the migration and maintenance of pigment cells. In one case (m), detailed information concerning the specific nature of the genetic defect is available.The goal of this article is to demonstrate ways in which the existing information on the axolotl color genes can best be utilized in terms of understanding not only the mutant phenotypes, but basic concepts in the cell and developmental biology of pigmentation as well. Thus, an attempt has been made to sort through the genetic and biochemical data relevant to these mutants in order to stimulate renewed interest in a more detailed pursuit of such studies.
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  • 61
    ISSN: 0192-253X
    Keywords: Drosophila virilis ; high temperature ; p-esterase ; juvenile hormone ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Drosophila virilis stocks differing in reaction to high temperature (32°C) were studied. The sizes of the larval salivary glands, ring gland, and imaginal discs of the heat-sensitive stock 147, whose pupal (p) esterase was activated at 32°C, were found to be significantly smaller at high temperature than at 25°C. In larvae of the heat-resistant stock 101, whose p-esterase was inactivated at 32°C, the salivary glands and imaginal discs were larger under conditions of high temperature than those of the control larvae. Treatment of stock 147 larvae with ecdysone at 32°C did not affect p-esterase activity and was 100% lethal. By contrast, the juvenile hormone activated p-esterase under these conditions and normalized the development of stock 147 larvae. A scheme is suggested for the role of p-esterase in the regulation of the hormonal status of D. virilis under high temperature conditions.
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    Developmental Genetics 1 (1979), S. 325-330 
    ISSN: 0192-253X
    Keywords: abscisic acid ; embryo culture ; vivipary ; Zea mays ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The plant hormone abscisic acid (ABA) is believed to play a role in the onset of developmental arrest in seeds. Embryos of the viviparous mutants of Zea mays do not undergo arrest but germinate directly on the ear. This study investigates the possibility that the mutants vp1, vp5, vp7, vp8, and vp9 are defective in some aspect of ABA action. Mutant and wild type embryos were removed from developing seeds at 18, 21, and 24 days after pollination and cultured aseptically on media containing a range of ABA concentrations. Seedlings were harvested after seven days when lengths and fresh and dry weights were recorded. The results indicate that these five viviparous mutants differ in their response to ABA. Two mutants, vp5 and vp8, exhibit the same sensitivity to growth inhibition by ABA as wild type. The remaining three mutants, however, manifest a range of decreased sensitivities with vp1 being the least sensitive, followed by vp7 and vp9.
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  • 63
    ISSN: 0192-253X
    Keywords: temporal-regulatory gene ; alcohol dehydrogenase ; gene regulation ; recessive trans-acting gene ; Zea mays ; developmental program ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The developmental program of alcohol dehydrogenase (ADH) activity in the scutellum of maize strain R6-67 is different from that of W64A. The level of scutellar ADH activity in R6-67 remains relatively high during the course of early sporophytic development as compared to the commonly observed pattern. In the typical inbred strain W64A, the activity of ADH declines substantially during that period. The variance values from the crosses between R6-67 and W64A reveal that the trait is under genetic control. Detailed genetic analysis suggests that a single gene is responsible for the altered developmental program of ADH activity in R6-67. This gene meets the criteria for temporal regulatory genes and is different from Adh2, the structural gene which codes the ADH-2 isozyme. We have designated this gene as Adr1 (alcohol dehydrogenase regulator, #1). Adr1 is unlinked to Adh2. There is no de novo synthesis of ADH in the scutellum during germination, and the difference in the activity level reflects the difference in the amount of enzyme protein as demonstrated by density labeling and rocket immunoelectrophoresis. Thus, it appears that Adr1 may regulate the degradation of ADH.
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    Developmental Genetics 1 (1979), S. 331-340 
    ISSN: 0192-253X
    Keywords: heat-shock ; proteins ; tobacco ; soybean ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Tobacco (Nicotiana tabacum) and soybean (Glycine max) tissue culture cells were exposed to a heat shock and protein synthesis studied by SDS-polyacrylamide gel electrophoresis after labeling with radioactive amino acids. A new pattern of protein synthesis is observed in heat-shocked cells compared to that in control cells. About 12 protein bands, some newly appearing, others synthesized in greatly increased quantities in heat-shock cells, are seen. Several of the heat-shock proteins (HSPs) in both tobacco and soybean are similar in size. One of the HSPs in soybean (76K) shares peptide homology with its presumptive 25°C counterpart, indicating that the synthesis of at least some HSPs may not be due to activation of new genes. The optimum temperature for maximal induction of most HSPs is 39-40°C. Total protein synthesis decreases as heat-shock temperature is increased and is barely detectable at 45°C. The heat-shock response is maintained for a relatively short time in tobacco cells. After 3 hr at 39°C, a decrease is seen in the synthesis of the HSPs, and after 4 hr practically no HSPs are synthesized. After exposure to 39°C for 1 hr, followed by a return of tobacco cells to 26°C, recovery to the control pattern of synthesis requires greater than 6 hours. These results indicate that cells of flowering plants exhibit a heat-shock response similar to that observed in animal cells.
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    Developmental Genetics 1 (1979), S. 341-353 
    ISSN: 0192-253X
    Keywords: PGK-B ; LDH-C4 ; sperm isozymes ; cryptorchism ; spermatogenesis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The hypothesis that PGK-B, like LDH-C4, is restricted to spermatogenic cells was explored by examining isozyme patterns in testes from mice depleted of germinal cells by surgical cryptorchism. In experimentally cryptorchized C57BL/10Sn males, decline in PGK-B activity paralleled decline in LDH-C4 activity and was correlated with degeneration of spermatocytes, spermatids, and spermatozoa. Trace amounts of these sperm isozymes found in cryptorchid testes after the depletion of maturing germ cells probably came from degenerated spermatids and spermatocytes and not from somatic testicular cells.
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    Developmental Genetics 1 (1979), S. 355-362 
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; spore maturation ; spore specific mutations ; cell patterning ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three mutations affecting spore maturation in the asexual fruiting body of Dictyostelium discoideum are assigned to a new locus, sprJ, on linkage group IV. Strains carrying mutations at the sprJ locus do not form mature spores, yet the cell patterning (spore, stalk and disc cell ratios) is apparently normal. These mutations will be useful to delineate branch points between the cell patterning and spore maturation pathways. There are some unusual features of the sprJ-containing mutants. In particular each of the parent strains of the three mutants has incomplete spore maturation as determined by colony-forming ability after heat shocking at 45°C. A mutation allowing growth in the presence of benlate (600 μg/ml), benA351, is mapped to linkage group I.
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    Developmental Genetics 1 (1979), S. 363-378 
    ISSN: 0192-253X
    Keywords: maize ; mitochondrial DNA ; recombinant DNA ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Twenty-eight Bam H 1 restriction fragments were isolated from normal mitochondrial DNA of maize by recombinant DNA techniques to investigate the organization of the mitochondrial genome. Each cloned fragment was tested by molecular hybridization against a Bam digest of total mitochondrial DNA. Using Southern transfers, we identified the normal fragment of origin for d each clone. Twenty-three of the tested clones hybridized only to the fragment from which the clone was derived. In five cases, labeling of an additional band indicated some sequence repetition in the mitochondrial genome. Four clones from normal mitochondrial DNA were found which share sequences with the plasmid-like DNAs, S-1 and S-2, found in S male sterile cytoplasm. The total sequence complexity of the clones tested is 121×106 d (daltons), which approximates two thirds of the total mitochondrial genome (estimated at 183×106 d).Most fragments do not share homology with other fragments, and the total length of unique fragments exceeds that of the largest circular molecules observed. Therefore, the different size classes of circular molecules most likely represent genetically discrete chromosomes in a complex organelle genome. The variable abundance of different mitochondrial chromosomes is of special interest because it represents an unusual mechanism for the control of gene expression by regulation of gene copy number. This mechanism may play an important role in metabolism or biogenesis of mitochondria in the development of higher plants.
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    Biologie in unserer Zeit 9 (1979) 
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    Keywords: Life and Medical Sciences
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    Biologie in unserer Zeit 9 (1979), S. A5 
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    Biologie in unserer Zeit 9 (1979), S. A6 
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    Biologie in unserer Zeit 9 (1979), S. 1-8 
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    Keywords: Life and Medical Sciences
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    Biologie in unserer Zeit 9 (1979), S. 9-13 
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    Keywords: Life and Medical Sciences
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    Biologie in unserer Zeit 9 (1979), S. 14-23 
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    Keywords: Life and Medical Sciences
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    Biologie in unserer Zeit 9 (1979), S. 28-29 
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    Biologie in unserer Zeit 9 (1979), S. 24-27 
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    Keywords: Life and Medical Sciences
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    Biologie in unserer Zeit 9 (1979) 
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    Biologie in unserer Zeit 9 (1979), S. 30-32 
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    Biologie in unserer Zeit 9 (1979), S. A16 
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    Biologie in unserer Zeit 9 (1979), S. A18 
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    Biologie in unserer Zeit 9 (1979), S. 40-44 
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    Biologie in unserer Zeit 9 (1979), S. 33-39 
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    Biologie in unserer Zeit 9 (1979), S. 52-57 
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    Biologie in unserer Zeit 9 (1979), S. 58-60 
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    Biologie in unserer Zeit 9 (1979), S. 64-64 
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