Semen

About: Semen is a research topic. Over the lifetime, 14571 publications have been published within this topic receiving 407739 citations. The topic is also known as: come & ejaculate.

Comparative analysis of three sperm DNA damage assays and sperm nuclear protein content in couples undergoing assisted reproduction treatment

Abstract: main results and the role of chance: Histone retention was associated with sperm DNA damage (P , 0.001), reduced embryo quality (P ¼ 0.005) and clinical pregnancies (P , 0.001). The mean percentage of sperm with DNA damage was significantly higher in sperm from non-pregnant couples compared with that from pregnant couples, as measured by TUNEL assay (15.04+ 1.16% versus 8.79+ 0.56%; P , 0.001) and alkaline Comet assay (72.79+ 2.49% versus 55.86+ 2.29%; P , 0.001). There was no association between clinical pregnancies and DNA fragmentation index measured by FCCE (12.97+ 1.46 versus 14.93+ 1.65; P ¼ 0.379). Of the protamine parameters analysed, only the P1/P2 ratio was associated with sperm count (P ¼ 0.013), men’s age (P ¼ 0.037), maturity (P ¼ 0.049) and blastocyst quality (P ¼ 0.012). Histone retention and sperm DNA damage measured by Comet and TUNEL assays were associated with fertilization rate (P , 0.05), embryo quality (P , 0.05) and implantation rate (P , 0.05). limitations,reasonsforcaution: A potential drawback of this study is that it is cross-sectional. Generally in such studies there is more than one variable that could cause the effect. Analysing sperm is one part of the equation; there are also a number of female factors that have the potential to influence ART outcomes. Therefore, given the large and well-established role of female factors in infertility, normal sperm DNA integrity and protamination do not necessarily ensure clinical pregnancy in ART. Thus, female factors can reduce the prognostic value of sperm DNA tests. Further, our use of native semen instead of prepared sperm may have iatrogenically increased the DNA damage. widerimplications of the findings: Alteration in sperm nuclear protein affects sperm DNA integrity. Further, with the current dataset, TUNEL and Comet assays appeared more predictive of ART success than FCCE.

Update on sexed semen technology in cattle

Abstract: The technology in current use for sexing sperm represents remarkable feats of engineering. These flow cytometer/cell sorters can make over 30 000 consecutive evaluations of individual sperm each second for each nozzle and sort the sperm into three containers: X-sperm, Y-sperm and unsexable plus dead sperm. Even at these speeds it is not economical to package sperm at standard numbers per inseminate. However, with excellent management, pregnancy rates in cattle with 2 million sexed sperm per insemination dose are about 80% of those with conventional semen at normal sperm doses. This lowered fertility, in part due to damage to sperm during sorting, plus the extra cost of sexed semen limits the applications that are economically feasible. Even so, on the order of 2 million doses of bovine semen are sexed annually in the United States. The main application is for dairy heifers to have heifer calves, either for herd expansion or for sale as replacements, often for eventual export. Breeders of purebred cattle often use sexed semen for specific matings; thawing and then sexing frozen semen and immediately using the few resulting sexed sperm for in vitro fertilization is done with increasing frequency. Beef cattle producers are starting to use sexed semen to produce crossbred female replacements. Proprietary improvements in sperm sexing procedures, implemented in 2013, are claimed to improve fertility between 4 and 6 percentage points, or about 10%.

The Taurine and Hypotaurine Content of Human Semen

Abstract: Taurine and hypotaurine levels were measured in human sperm and seminal fluid. Sperm taurine ranged from 17 nmol/mg DNA to 348 nmol/mg DNA, and hypotaurine from 0 nmol/mg DNA to 251 nmol/mg DNA. Seminal fluid contained 319 mumol/L to 1590 mumol/L of taurine, but no detectable hypotaurine. The coefficient of variation in multiple ejaculates from a single man for these components ranged from 12% for hypotaurine to 24% for seminal fluid taurine, indicating a relative constancy in their concentrations. Sperm hypotaurine content was significantly correlated with sperm morphology, sperm relative forward progression, the percentage of motile sperm, and the total number of sperm in the ejaculate. By contrast, sperm taurine content was negatively correlated with these parameters. The mean hypotaurine content of sperm from 8 fertile men was 149 +/- 92 nmol/mg DNA, four times higher than that of sperm from 9 infertile men, which was 35 +/- 19 nmol/mg DNA (P = 0.011). In contrast, the mean sperm taurine content of the fertile men was lower than that of the infertile men (83 +/- 33 nmol/mg DNA versus 168 +/- 119 nmol/mg DNA, respectively; P = 0.07). Seminal fluid taurine concentrations, however, were similar for both groups. Hypotaurine, an antioxidant, may play an important role in protecting sperm from reactive oxygen species. Higher concentrations of taurine in the sperm of infertile men suggest that accelerated oxidation of hypotaurine to taurine may accompany the observed decline in other sperm parameters.