Evolution of sperm morphology in

Polyandry reduces sperm length variation in social insects.

Postcopulatory sexual selection, either in the form of sperm competition or cryptic female choice, is an important selective force that is thought to have generated the enormous variation in sperm morphology observed interspecifically. However, the evolutionary significance of intraspecific variation in sperm morphology, and the role that postcopulatory sexual selection plays in influencing thi...

The maintenance of sperm variability: context-dependent selection on sperm morphology in a broadcast spawning invertebrate.

Why are sperm so variable despite having a singular, critical function and an intimate relationship with fitness? A key to understanding the evolution of sperm morphology is identifying which traits enable sperm to be successful fertilizers. Several sperm traits (e.g., tail length, overall size) are implicated in sperm performance, but the benefits of these traits are likely to be highly contex...

The Influence of Sperm Morphology, Total Motile Sperm Count of Semen and the Number of Motile Sperm Inseminated in Sperm Samples on the Success of Intrauterine Insemination

THE CORRELATION BETWEEN SPERM MORPHOLOGY AND MOTILITY IN FERTILE AND INFERTILE MEN

The swim-up procedure was used to collect a sperm fraction with improved motility and normal morphology from fertile and infertile semen samples. The untreated and swim-up fractions were analyzed with the Hamilton-Thorn Motility Analyser. Comparisons were made to see the effect of this sperm selection technique on sperm motility and morphology. They were then examined by transmission elect...

Evolution of larger sperm in response to experimentally increased sperm competition in Caenorhabditis elegans.

Sperm morphology evolves rapidly, resulting in an exceptional diversity of sperm size and shape across animal phyla. This swift evolution has been thought to prevent fertilizations between closely related species. Alternatively, recent correlative analyses suggest that competition among sperm from more than one male may cause sperm diversity, but these hypotheses have not been tested. Here, we ...

P-9: A New Morphology Staining Method for Sperm of Some Domestic Animals

Background: There are some methods for morphology staining of sperm. Although many different and also new methods are used in semen analysis, light microscopy is still used for routine morphological evaluation. The most used of the methods is Papanicolaou staining. This method is routinely used in Andrology laboratory for Human sperm morphology staining. In some domestic animals such as bull, R...