Post-copulatory sexual selection in the form of sperm competition is known to influence the evolution of male reproductive proteins in mammals. The relationship between sperm competition and regulatory evolution, however, remains to be explored. Protamines and transition nuclear proteins are involved in the condensation of sperm chromatin and are expected to affect the shape of the sperm head. ...

The sperm cell has a characteristic polarized morphology and its surface is also highly differentiated into different membrane domains. Junctional protein ring structures seal the surface of the mid-piece from the head and the tail respectively and probably prevent random diffusion of membrane molecules over the protein rings. Despite the absence of such lateral diffusion-preventing structures,...

OBJECTIVE The presence of sperm-head vacuoles has been suspected to be deleterious to the outcomes of assisted reproductive technology (ART). It is difficult to accurately distinguish morphologically abnormal sperm with vacuoles under a light microscope. This study was performed to analyze the result of the observation of sperm-head vacuoles using Papanicolaou staining under a light microscope ...

Background According to a worldwide survey in 2010 infertility affects 48.5 million of couples. In roughly half of the cases infertility is provoked by the male mate. Thus, a significant percentage of young men are infertile but the underlying causes are mostly unknown. Male fertility and reproduction success critically depends on proper formation of the mature sperm. Transmission of the geneti...

Introduced in 2001, intracytoplasmic morphologically selected sperm injection (IMSI) represents a more sophisticated way of ICSI whereby, prior to injection, the spermatozoon is selected at higher magnification. Doing so, the spermatozoon can be evaluated for fine integrity of its nucleus and the injection of a normal spermatozoon with a vacuole-free head can be assured. Additional research is ...

The present study aimed to investigate effects of the heavy metal Cd on the sperm morphological indices of Caspimyzon wagneri. The sperm were exposed to 0.01, 0.1, 1, 10, 100 and 1000 mg.L‑1 Cd for three minutes, three and 36 hours. The sperms exposed to Cd showed an increase in the length, width and surface of the head, flagella degradation and slightly flagella breakage.  With increase of Cd ...

When Pisaster, Asterias, or Thyone sperm are treated with the ionophore A23187 or X537A, an acrosomal reaction similar but not identical to a normal acrosomal reaction is induced in all the sperm. Based upon the response of the sperm, the acrosomal reaction consists of a series of temporally related steps. These include the fusion of the acrosomal vacuole with the cell surface, the polymerizati...

When Pisaster, Asterias, or Thyone sperm are treated with the ionophore A23187 or X537A, an acrosomal reaction similar but not identical to a normal acrosomal reaction is induced in all the sperm. Based upon the response of the sperm, the acrosomal reaction consists of a series of temporally related steps. These include the fusion of the acrosomal vacuole with the cell surface, the polymerizati...

introduction: the incidence of sperm and oocyte premature chromosome condensation (pcc) in the failed fertilized oocytes that were taken after routine in viro fertilization (ivf) and intracytoplasmic sperm injection (icsi) programs were investigated. materials and methods: in this study, 364 air-dried preparations of failed fertilized oocytes after either ivf or ocsi procedures were analyzed. t...

The dark staining of human sperm heads by Diff Quik is significantly correlated with abnormal sperm head morphology (r=0.51, p<0.0001), but is not associated with changes in sperm chromatin detected by a sperm chromatin structure assay (SCSA; r=0.18, p>0.09). Whilst valuable in the assessment of head morphology, it is concluded that Diff Quik staining is not a useful substitute for the SCSA to ...