Sperm competition was identified in 1970 as a pervasive selective force in post‐copulatory
sexual selection that occurs when the ejaculates of different males compete to fertilise a …

Females frequently mate with several males, whose sperm then compete to fertilize
available ova. Sperm competition represents a potent selective force that is expected to …

Females of many species mate with multiple males, thereby inciting competition among
ejaculates from rival males for fertilization. In response to increasing sperm competition …

Sperm experience intense and varied selection that dramatically impacts the evolution of
sperm quality. Selection acts to ensure that sperm are fertilization-competent and able to …

Background The influence of sperm competition upon sperm size has been a controversial
issue during the last 20 years which remains unresolved for mammals. The hypothesis that …

Evolutionary biologists have endeavoured to explain the extraordinary diversity of sperm
morphology across animals for more than a century. One hypothesis to explain sperm …

While both sperm number and quality are now recognized to be important in determining the
outcome of sperm competition, very few studies have experimentally assessed the influence …

Sperm morphological variation has attracted considerable interest and generated a wealth
of predominantly descriptive studies over the past three centuries. Yet, apart from …

Cholesterol provided by low-or high-density lipoprotein is the precursor for biosynthesis of
progesterone. Once inside the cell, cholesterol can be used for steroidogenesis or esterified …

The spermatozoon is a highly differentiated and polarized cell, with two main structures: the
head, containing a haploid nucleus and the acrosomal exocytotic granule, and the flagellum …