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.

Oocyte signals derived from polyunsaturated fatty acids control sperm recruitment in vivo.

Abstract: A fundamental question in animal development is how motile cells find their correct target destinations. During mating in the nematode Caenorhabditis elegans, males inject sperm through the hermaphrodite vulva into the uterus. Amoeboid sperm crawl around fertilized eggs to the spermatheca – a convoluted tube where fertilization occurs1,2. Here, we show that polyunsaturated fatty acids (PUFAs), the precursors of eicosanoid signalling molecules, function in oocytes to control directional sperm motility within the uterus. PUFAs are transported from the intestine, the site of fat metabolism, to the oocytes yolk, which is a lipoprotein complex. Loss of the RME-2 low-density lipoprotein (LDL) receptor, which mediates yolk endocytosis3 and fatty acid transport into oocytes, causes severe defects in sperm targeting. We used an RNAi screen to identify lipid regulators required for directional sperm motility. Our results support the hypothesis that PUFAs function in oocytes as precursors of signals that control sperm recruitment to the spermatheca. A common property of PUFAs in mammals and C. elegans is that these fats control local recruitment of motile cells to their target tissues.

Effects of Psychological Stress on Human Semen Quality

Abstract: We investigated the relationship between psychological stress and sperm concentration, motility, and morphometry in a prospective study of 157 volunteers who were enrolled in a prepaid health plan We measured psychological job stress and life-event stress by telephone interview Sperm-kinematic and nuclear-morphometric variables were measured using computer-assisted image analyses Sperm concentration, percent motility, and semen volume were determined by objective visual methods We performed multiple linear regression for each semen variable to examine its relationship to stress, controlling for potential confounders Stress at work and total number of life events were not related to differences in semen quality However, the recent death of a close family member was associated with a reduction in straight-line velocity (P = 0002) and percent of progressively motile sperm (P = 002); it was also marginally associated with an increase in the fraction of sperm with larger and more tapered nuclei These findings suggest that the fecundity of men experiencing the stress of a family member's death might be temporarily diminished

Human semen quality and sperm DNA damage in relation to urinary metabolites of pyrethroid insecticides

Abstract: BACKGROUND: Exposure to synthetic pyrethroid insecticides is widespread, and is expected to increase among the general population due to the need to replace other common insecticides following regulatory use restrictions. On the basis of limited studies, there is animal and human evidence for altered reproductive or endocrine function following pyrethroid exposure. METHODS: The present study measured urinary pyrethroid metabolites [3-phenoxybenzoic acid (3PBA) and cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (CDCCA and TDCCA)], semen quality, sperm motion parameters and sperm DNA damage with the neutral comet assay in 207 men recruited from an infertility clinic. RESULTS: In multivariate analysis, the highest 3PBA quartile was associated with a suggestive 20.2 million sperm/ml reduction (95% confidence interval 237.1 to +2.6) in sperm concentration compared with men below the 3PBA median. There were significant inverse associations between TDCCA and sperm motility and sperm motion parameters when adjusting for CDCCA and other covariates. The highest TDCCA quartile was associated with a 15.5% decline (95% confidence interval 226.2 to 24.8) in sperm motility compared with men below the median. In multiple logistic analyses, there were dose-dependent increased odds for below reference sperm concentration, motility and morphology in relation to TDCCA. Among the comet assay measures, 3PBA and CDCCA were associated with increased sperm DNA damage, measured as percent DNA in the comet tail. CONCLUSIONS: We found evidence for reduced semen quality and increased sperm DNA damage in relation to urinary metabolites of pyrethroid insecticides. These findings may be of concern due to increased pyrethroid use and prevalent human exposure.

Mutation of the Cα Subunit of PKA Leads to Growth Retardation and Sperm Dysfunction

Abstract: The intracellular second messenger cAMP affects cell physiology by directly interacting with effector molecules that include cyclic nucleotide-gated ion channels, cAMP-regulated G protein exchange factors, and cAMP-dependent protein kinases (PKA). Two catalytic subunits, Calpha and Cbeta, are expressed in the mouse and mediate the effects of PKA. We generated a null mutation in the major catalytic subunit of PKA, Calpha, and observed early postnatal lethality in the majority of Calpha knockout mice. Surprisingly, a small percentage of Calpha knockout mice, although runted, survived to adulthood. This growth retardation was not due to decreased GH production but did correlate with a reduction in IGF-I mRNA in the liver and diminished production of the major urinary proteins in kidney. The survival of Calpha knockout mice after birth is dependent on the genetic background as well as environmental factors, but sufficient adult animals were obtained to characterize the mutants. In these animals, compensatory increases in Cbeta levels occurred in brain whereas many tissues, including skeletal muscle, heart, and sperm, contained less than 10% of the normal PKA activity. Analysis of sperm in Calpha knockout males revealed that spermatogenesis progressed normally but that mature sperm had defective forward motility.

Acrosomal status and mitochondrial activity of human spermatozoa vitrified with sucrose.

Abstract: This study investigates the ability of sucrose to protect spermatozoa against mitochondrial damage, artificial cryoinduction of capacitation, and acrosome reaction. Spermatozoa were isolated using the swim-up procedure performed using three different media: (a) human tubal fluid (HTF, control) medium; (b) HTF with 1% human serum albumin (HSA); and (c) HTF with 1% HSA and 0.25 M sucrose. From each group, 30 mul suspensions of cells were dropped directly into liquid nitrogen and stored for at least 24 h. Cells were thawed by quickly submerging the spheres in HTF with 1% HSA at 37 degrees C with gentle agitation. Sperm motility, viability, mitochondrial membrane potential integrity, spontaneous capacitation, and acrosome reaction were investigated. Sperm viability, acrosome reaction, and capacitation were detected using the double fluorescence chlortetracycline-Hoechst 33258 staining technique. Mitochondrial function was evaluated using a unique fluorescent cationic dye, 5,5',6,6'-tetrachloro-1-1',3,3'-tetraethyl-benzamidazolocarbocyanin iodide, commonly known as JC-1. The number of progressively motile spermatozoa was significantly higher in the sucrose-supplemented medium group (57.1+/-3.2%, P<0.05) when compared with controls (19.4+/-1.9%). The combination of HSA and sucrose (65.2+/-2.6%) has a stronger cryoprotective effect on the integrity of mitochondrial membrane potential (P<0.05) compared with HSA alone (32.6+/-4.7%). In conclusion, vitrification of human spermatozoa with non-permeable cryoprotectants such as HSA and sucrose can effectively cryopreserve the cells without significant loss of important physiological parameters.