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51.
An in vitro binding assay involving egg plasma membrane vesicles (PMVs) of Fucus serratus L. and proteins contained in a KCl extract of sperm has been used to identify a sperm protein involved in egg binding. High-performance gel filtration (HPGF) separated the sperm KCl extract into several major fractions, and a protein (apparent M, 60 kDa) was identified as being involved in binding to the egg PMVs. This protein ran on denaturing sodium dodecyl sulfate (SDS)gels with an apparent molecular weight of 27 kDa. This suggests that either the native form of the protein is a dimer or the molecular weight on HPGF is an artifact caused by high ionic strength buffer promoting hydrophobic interactions. When KCl-sol-uble proteins were separated by SDS-polyacrylamide gel electrophoresis (PAGE), blotted onto nitrocellulose, and incubated with biotinylated egg PMVs, these bound to a band at 27 kDa, confirming the role of this protein. Addition of the Fucus sperm extract or HPGF fractions containing the binding protein to eggs in the absence of sperm induced the release of polysaccharides onto the egg cell surface. This labeling was patchy, in contrast to the uniform release of polysaccharides observed when sperm were added to eggs. The monoclonal antibody (MAb) FS17 was raised against the 27-kDa sperm protein. It labeled the sperm body and both flagella by immunofluorescence, though the sperm had to he permeabilized to observe labeling, suggesting that the epitope recognized is not exposed at the cell surface. Addition of FS17 to the KCl extract in the binding assay reduced subsequent binding of egg PMVs. Removal of the 27-kDa protein recognized by FS17 from the sperm extract prevented the binding of egg PMVs in the binding assay and the triggering of the patchy release of polysaccharides when added to eggs. Overall the results suggest that the 27-kDa sperm protein is involved in binding to the egg plasma membrane and can trigger partial activation of the egg . 相似文献
52.
T Subramoniam 《Journal of biosciences》1995,20(5):691-706
Unlike the other penaeiodean shrimp, the ridge back shrimp, Sicyoniaingentis does not produce a spermatophore, but transfers sperm suspended in seminal plasm. This paper reports on the histomorphology
and ultrastructure of the vas deferens with reference to its functional role in secreting the sperm bearing materials. The
vas deferens is divisible into proximal secretory, mid storage and distal ejaculatory regions. The epithelial cells lining
the proximal vas deferens are comprised of secretory and absorptive cell types. The loose sperm cells found in the lumen of
this region are in an immature condition, and are agglutinated into a compact mass with signs of spermiogenesis in the mid
vas deferens. The epithelial cells lining the mid vas deferens are short flattened cells. The distal vas deferens is ensheathed
by muscular fibres. The inner epithelial cells are highly secretory and contain numerous microvilli at the luminal end. The
sperm cord gets liquefied in this region facilitating the transfer of sperm in liquid form to the female during mating. 相似文献
53.
Summary To facilitate the study of mating biology in the desert leaf-cutter antAcromyrmex versicolor, methods were developed that allowed storage and easy quantification of sperm samples collected from both male and female reproductive tracts. Sperm samples stored frozen were sonicated, stained with a fluorescent DNA stain, and the fluorescence emitted by the stained sperm heads was measured. The intensity of fluorescence was shown to be a linear function of the number of sperm in the sample as determined by counting. 相似文献
54.
We determined the fertilization rates achieved by males of the polygynous wrasse Xyrichtys novacula in the northern Mediterranean sea, by collecting all sperms and eggs released in individual spawns from three adjacent male territories that encompassed different numbers of female home ranges. Two males with territories including four and six females respectively, released similar average numbers of sperm/spawn, whereas a male holding at the same time two territories with six females each, released significantly fewer sperm/spawn. Although fertilization rates decreased with absolute numbers of sperm released, the male with the largest harem achieved the highest total daily number of fertilized eggs, as a result of the high number of females in his territory. These results demonstrate a strategy of a male's sperm economy that is in conflict with the female's interests. 相似文献
55.
Mona El Agoze Marylène Poirié Georges Périquet 《Entomologia Experimentalis et Applicata》1995,75(3):251-255
In most insect species where double matings occur, sperm from the second male preferentially fertilize subsequent eggs. However,
we demonstrate here that, as already shown for some other hymenopteran species, this is not the case in the ichneumonid waspDiadromus pulchellus (Wesmeal): sperm from the first male usually father all the female progeny. This precedence of the first male sperm is also
observed in double matings involving an haploid male and a diploid sterile male, whichever is the first mating male. We discuss
the consequences of this phenomenon from an evolutionary point of view. 相似文献
56.
We observed changes with time in the patterns of characteristic fluke markings used to identify sperm whales. Changes were categorized as minor, moderate, or major based on their severity. These change types were found to occur at rates of 0.9%, 11.8%, and 1.3% per individual per year, respectively. Gain and loss rates for each of seven different mark types were also calculated. The highest estimated rate was the gain of small nicks at 0.08 per individual per year. Most individuals identified by us possess at least a few characteristic marks and, therefore, changes of the type observed in this study are unlikely to severely affect their recognizability. For all but one mark type, gain rates were higher than loss rates, indicating that individuals may be accumulating marks with age. Over long periods this could eventually make individuals unrecognizable, with the result that population sizes calculated from these data may be overestimated. As long as photoidentification studies are conducted sufficiently often, and these changes are as gradual as they appear to be, this problem should be minimal. 相似文献
57.
人胚DA能神经元移植于帕金森氏病猴模型的TH免疫细胞化学的研究 总被引:3,自引:0,他引:3
为了对人胚黑质DA神经元移植治疗PD人的临床应用作出客观评估,将8-12周人胚黑质细胞移植到用MPTP诱发的偏侧PD猴新纹状体内。实验动物分别存活2个月、5个月和1年后,用TH免疫细胞化学方法对被移植的人胚DA细胞的存活和与宿主间的突触联系进行检查。在光镜下可见被移植侧的新纹状体内有TH阳性细胞,它们成小群散在分布,每小群有3-10个细胞。TH阳性细胞的轴突延伸到整个新纹状体,树突呈现出正常发育过 相似文献
58.
The SEA module: a new extracellular domain associated with O-glycosylation. 总被引:4,自引:1,他引:3
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Using a variety of homology search methods and multiple alignments, a new extracellular module was identified in (1) agrin, (2) enterokinase, (3) a 63-kDa sea urchin sperm protein, (4) perlecan, (5) the breast cancer marker MUCI (episialin), (6) the cell surface antigen 114/A10, and (7/8) two functionally uncharacterized, probably extracellular, Caenorhabditis elegans proteins. Despite the functional diversity of these adhesive proteins, a common denominator seems to be their existence in heavily glycosylated environments. In addition, the better characterized proteins mentioned above contain all O-glycosidic-linked carbohydrates such as heparan sulfate that contribute considerably to their molecular masses. The common module might regulate or assist binding to neighboring carbohydrate moieties. 相似文献
59.
DNA fingerprinting of tadpoles from two different ‘one female-two male’ matings of the red-eyed treefrog, Agalychnis callidryas, revealed multiple paternity of offspring. Offspring were assigned paternity based on bands shared with the putative father, but not shared between putative fathers or with the mother. Paternity was split 44/56% and 36/64% in two matings. These results do not support a hypothesis of sperm priority in access to unfertilized eggs by primary males. Multiple paternity may be commonplace in species of anurans with matings by multiple males. 相似文献
60.
A 275-MHz exposure system, consisting of a circular waveguide irradiator and a transparent plastic animal cage, has been developed to accommodate rhesus monkeys weighing up to 15 kg. The vertically oriented waveguide is composed primarily of stainless steel and is fitted with an inner cage fabricated from a tubular section of acrylic plastic. Circularly polarized electromagnetic energy at 275 MHz, either pulsed or continuous wave (CW), can be propagated from the removable top section of the waveguide. The cage is designed to function as the monkey's permanent home. It is fitted with a lever-actuated behavioral performance device on which the monkey responds according to a predetermined schedule to obtain a daily food ration. The system can be adapted to provide for the collection of metabolic and physiologic data as well. Dosimetric measurements were conducted with six rhesus monkeys weighing 3.0-7.2 kg and with a 4-kg model. The dosimetric results show that about one-third of the net incident energy is absorbed by a subject in this system at a normalized specific absorption rate (SAR) of 0.33 (W/kg)/(mW/cm2). 相似文献