Sperm motility

About: Sperm motility is a research topic. Over the lifetime, 13874 publications have been published within this topic receiving 416587 citations. The topic is also known as: sperm movement & GO:0097722.

The human spermatozoon--not waving but drowning.

Abstract: The human male produces the poorest quality semen of all mammalian species studied to date. This alarming fact is illustrated by the World Health Organization’s recent reference text on human seminology (World Health Organization, 1999) which suggests that up to 85% of spermatozoa may be morphologically abnormal, even in the fertile male population. The abnormally shaped spermatozoa that appear endemic to our species also seem to possess a diminished capacity for fertilization, given that defective sperm function is the commonest, defined cause of human infertility (Hull et al., 1985). The morphological abnormalities that dominate the human semen profile may take many forms, but retention of excess residual cytoplasm in the midpiece of the spermatozoa and defects in the acrosomal region appear to be particularly important (Keating et al, 1997; Garrett et al., 1997). Impaired sperm motility, asthenozoospermia, is another common cause of defective human sperm function. This is a very dynamic aspect of sperm biology that is particularly susceptible to environmental interference, such as workplace exposure to organic solvents (Wang et al., 2001; Xiao et al., 2001). In the wake of such defects in semen quality, the human species is distinguished by a higher rate of spontaneous abortions and birth defects than any other mammal. In light of such data, it is difficult to avoid the conclusion that something is seriously wrong with spermatogenesis in the human male.

The effect of intracytoplasmic sperm injection and semen parameters on blastocyst development in vitro

Abstract: The present study compares the development and quality of blastocysts derived from conventional oocyte insemination with those derived from intracytoplasmic sperm injection (ICSI). Oocytes were collected from patients undergoing ovarian stimulation with human menopausal gonadotrophins for IVF. Patients with normal semen were assigned to conventional oocyte insemination while those with progressive motility <20% and/or normal sperm morphology < or =4% were assigned to ICSI. Resulting embryos were cultured for up to 6 days. The mean number and percentage of embryos reaching the blastocyst stage and the mean number and percentage of blastocysts of high quality on days 5-6 were assessed for both treatment groups and compared. The influence of paternal factors (sperm concentration, motility, progressive motility, morphology) on blastocyst development and quality were assessed by regression analyses. Significantly more ICSI-derived embryos arrested at the 5- to 8-cell stage (P = 0.024) concomitant with the activation of the paternal genome than those derived from conventional oocyte insemination. Significantly fewer ICSI-derived embryos reached the blastocyst stage on days 5-6 (P<0.001) and significantly fewer ICSI-derived embryos were of high quality (P = 0.002) compared with conventional oocyte insemination. When treatment groups were combined and evaluated by regression analysis, progressive motility and sperm morphology were significantly correlated with diminished blastocyst development and quality (P < 0.05). From these data, we conclude that paternal factors and/or performing ICSI in cases of severe male factor infertility may have a detrimental effect on blastocyst development and their quality.

Decreasing sperm quality: a global problem?

Abstract: Background Carlsen and coworkers (1992) reviewed 61 heterogeneous observational studies on semen quality published between 1938 and 1990. This review indicates that mean sperm density decreased significantly between 1940 and 1990. An extended meta-analysis with 101 studies confirmed a decline in sperm density for the period from 1934 to 1996 (2000). The key message of the meta-analyses is that sperm counts have decreased globally by about 50% over the past decades. This assessment has been questioned.

Sperm Swimming Velocity Predicts Competitive Fertilization Success in the Green Swordtail Xiphophorus helleri

Abstract: Sperm competition is expected to favour the evolution of traits that influence the performance of sperm when they compete to fertilize a female's eggs. While there is considerable evidence that selection favours increases in sperm numbers, much less is known about how sperm quality contributes towards competitive fertilization success. Here, we determine whether variation in sperm quality influences competitive fertilization success in the green swordtail Xiphophorus helleri, a highly promiscuous livebearing fish. We use artificial insemination as a method of controlled sperm delivery and show that sperm swimming velocity is the primary determinant of fertilization success when ejaculates from two males compete to fertilize a female's eggs. By contrast, we found no evidence that sperm length had any effect on siring success. We also found no evidence that pre- and postcopulatory sexual traits were phenotypically integrated in this species, suggesting that the previous observation that reproductive skew favours males with high mating rates is unlikely to be due to any direct association between sperm quality and male sexual ornamentation.