Abstract Reproductive success depends on efficient sperm movement driven by axonemal dynein-mediated microtubule sliding. Models predict sliding at the base of tail – centriole but such has never been observed. Centrioles are ancient organelles with a conserved architecture; their rigidity is thought to restrict Here, we show that, in mammalian sperm, atypical distal (DC) and its surrounding pe...

Bovine sperm protease, 66 kDa (BSp66) is a serine protease previously characterized in bovine spermatozoa. Like other proteases, it may be present in sperm from other mammalian species different from bovine, playing a role in the fertilization process. In this study, we looked for BSp66 in hamster spermatozoa using heterologous antibodies against bovine BSp66. An immunoreactive protein was dete...

Fertilin is a sperm surface protein with an essential role in fertilization. It is required for the migration of spermatozoa through the oviduct, for binding to the zona pellucida, and for efficient binding to the egg plasma membrane. Fertilin consists of two subunits, fertilin alpha and beta, both of which belong to the metalloprotease-disintegrin protein family (ADAMs). Fertilin alpha and bet...

Postcopulatory sexual selection is an important force in the evolution of reproductive traits, including sperm morphology. In birds, sperm morphology is known to be highly heritable and largely condition-independent. Theory predicts, and recent comparative work corroborates, that strong selection in such traits reduces intraspecific phenotypic variation. Here we show that some variation can be ...

OBJECTIVE To test whether sperm with abnormal head morphology are more likely to undergo DNA damage and/or chromatin modification during the process of freeze-thawing. DESIGN In this prospective study, the semen samples from forty-four men attending the infertility clinic were included. Samples were divided into aliquots to allow direct comparison of fresh and frozen spermatozoa from the same...

BACKGROUND Recently, motile sperm organelle morphology examination (MSOME) criteria as a new real time tool for evaluation of spermatozoa in intracytoplasmic sperm injection (ICSI) cycles has been considered. OBJECTIVE The aim was to investigate the predictive value of MSOME in in vitro fertilization (IVF) in comparison to ICSI cycles and evaluation of the association between MSOME parameters...

Mouse sperm were labeled in vivo with [3H]arginine. The sperm were then followed autoradiographically from the time of label incorporation until after fertilization. The label was completely lost from the sperm head after fertilization, during the oocyte's second meiotic division. That the [3H]arginine was incorporated into a sperm-specific basic protein was demonstrated by fractionating acid e...

The three-dimensional structure and size of ostrich sperm is unknown. In this study, the morphology and dimensions of ostrich sperm were determined by scanning electron microscopy of semen samples obtained from sexually mature males during the breeding season. The results indicate that sperm cells of the ostrich are of the sauropsid type characteristic of non-passerine birds and, in general app...

The flagellar force generated by a hyperactivated monkey spermatozoon was evaluated using the resistive force theory applied to the activated (nonhyperactivated) and hyperactivated flagellar waves that were obtained using high-speed video microscopy and digital image processing in order to clarify the mechanism of sperm penetration through the zona pellucida. No difference in the maximum propul...

BACKGROUND Identifying traits that reproductively isolate species, and the selective forces underlying their divergence, is a central goal of evolutionary biology and speciation research. There is growing recognition that postcopulatory sexual selection, which can drive rapid diversification of interacting ejaculate and female reproductive tract traits that mediate sperm competition, may be an ...