Txt sperm fertilize her eggs

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Gary F. What is the role of carbohydrates in the binding of human sperm to the zona pellucida ZP and what are potential implications for pathogenesis? Both lectin-like and protein—protein interactions play an essential role in human gamete interactions. Studies in the mouse and human indicate a role for both lectin-like and protein—protein interactions during sperm binding to the ZP. Ultrasensitive analysis by mass spectrometry of glycans linked to the human ZP has confirmed that this matrix is coated with a high density of complex type N-glycans terminated with the sialyl-Lewis x sLe x sequence, the universal selectin ligand.
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Paternity Battles | BioScience | Oxford Academic

Little is known about sperm allocation patterns in crustaceans, especially in anomuran crabs. We investigated whether male stone crabs, Hapalogaster dentata , change the number of ejaculated sperm depending on risk of sperm competition, and whether the pattern of sperm allocation to females of different body size varies with male body sizes in laboratory experiments where the male:female sex ratio SR and body size of both sexes in mating pairs were controlled. The number of ejaculated sperm differed significantly between matings under SR of and , and males showed an increase in number of ejaculated sperm in the presence of a potential rival male. These results suggest that sperm competition may occur in the stone crab, and superiority in number of ejaculated sperm relative to rival males would be important for increasing male reproductive success in this species. Larger males showed a significant increase in the number of ejaculated sperm with increasing female size, while smaller males did not. The size of the ejaculate passed to larger females by smaller males was significantly reduced, resulting in low fertilization rates of larger females.
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Refworks Account Login. Open Collections. UBC Theses and Dissertations. Featured Collection. An immature oocyte an e a r l y stage of development.
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Elia T. When a female yellow dung fly Scatophaga stercorarid is ready to lay her eggs, she searches her pasture or barnyard for a steaming fresh pile of cow dung. Male dung flies hover around the droppings like men at a singles bar, waiting for a chance to mate with arriving females. Although almost all female dung flies already have enough sperm in their specialized sperm-storage organs to fertilize their clutch of eggs, a female will nevertheless remate immediately before depositing her eggs on a suitable dung pile. The male with whom she has just mated then sits on her and guards her while she lays her eggs—that is, unless a bigger, stronger male comes along, muscles out the first male, and copulates with the female himself.
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