Collection frequency affects percent Y-chromosome bearing sperm, sperm head area and quality of bovine ejaculates

Chandler, John E.; Canal, A.M.; Paul, J.B.; Moser, E. Barry

doi:10.1016/s0093-691x(01)00721-x

Cited by 31 publications

(27 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the current study, the percentage of X-bearing sperm ranged from ~44% to 62%, which is closer to range of ~39% to 58% reported by Checa et al [6]. Chandler et al [11] evaluated the effects of semen collection frequency on semen sex ratio and reported the percentage of Y-bearing sperm changed in a sinusoid fashion over a period of 13.5 days. If the ratio of X-to Y-bearing sperm varies in a sinusoid fashion, that might explain the differences in semen sex ratios reported by various studies [4]- [6] [11].…”

Section: Discussionsupporting

confidence: 86%

“…Chandler et al [11] evaluated the effects of semen collection frequency on semen sex ratio and reported the percentage of Y-bearing sperm changed in a sinusoid fashion over a period of 13.5 days. If the ratio of X-to Y-bearing sperm varies in a sinusoid fashion, that might explain the differences in semen sex ratios reported by various studies [4]- [6] [11]. If this were the case, then frequent semen collections would be necessary to establish the fluctuation pattern and determine when the peak variation in semen sex ratio occurs.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Variation among Beef Bulls in the Ratio of X- to Y-Chromosome Bearing Spermatozoa

Rorie¹,

Delgado²,

Lester³

2014

ARSci

View full text Add to dashboard Cite

A study was conducted to evaluate variation in the ratio of X-to Y-bearing sperm of individual ejaculates and to determine any relationship between skewed sex ratio and either routine morphological evaluation or computer assisted sperm analysis (CASA). Semen was collected from bulls weekly for 6 consecutive weeks, sperm DNA was recovered and quantitative, and real-time PCR was used to determine the ratio of X-to Y-bearing sperm in each ejaculate. The overall mean of X-bearing sperm within ejaculates was 54.7% over the 6 weeks of semen collections. The percentages of X-bearing sperm were similar (P > 0.5) across all collections. Between bulls, there were differences (P < 0.05) in the mean percentage of X-bearing sperm. No significant correlations were found between CASA parameters and percentage of X-bearing sperm across bulls, so analysis was done within each bull. Different combinations of CASA and/or morphological parameters were found to correlate with the percentage of X-bearing sperm but the prediction equations were specific for individual bulls and unlikely to be of use across bulls. These results confirm that the ratio of X-to Y-bearing sperm may be skewed in some ejaculates of bull semen. Some sperm parameters measured by CASA or routine morphological evaluation were associated with semen sex ratio.

show abstract

Section: Discussionsupporting

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Variation among Beef Bulls in the Ratio of X- to Y-Chromosome Bearing Spermatozoa

Rorie¹,

Delgado²,

Lester³

2014

ARSci

View full text Add to dashboard Cite

show abstract

“…First, high-and low-fertility males could differ in the proportion of Y-bearing spermatozoa in the ejaculate (Chandler et al 2002) resulting in biases in sex ratio at birth. Second, differences between males in the competitiveness of X-and Y-bearing spermatozoa could arise through differential expression of genes carried in the sex chromosomes.…”

Section: Male Fertility and Offspring Sex Ratiomentioning

confidence: 99%

Sperm traits and male fertility in natural populations

Gomendio¹,

Malo²,

Garde³

et al. 2007

Reproduction

View full text Add to dashboard Cite

Male fertility has seldom been studied in natural populations because it has been assumed that strong selection would result in uniformly high values among males, and therefore mating success has been equated with fertilisation success. In contrast, male fertility has received much attention in studies of domestic livestock, where economic benefits rely on improving productivity, and in human infertility studies, where the efficiency of treatments depends on understanding which ejaculate traits explain reproductive failures and predict success at assisted conception. Despite years of efforts, no conclusive results have been obtained, probably because such studies have focused on opposite extremes of the range with little variation: domestic livestock have often been subject to strong artificial selection for high fertility, and human patients requiring treatment have compromised fertility. Recent findings from natural populations of red deer have shown that males differ markedly in their fertility, and have revealed the degree of variation found in different semen traits, both between and within males. Fertility trials have shown that male fertility is determined mainly by sperm swimming speed and the proportion of normal sperm, when sperm numbers are kept constant. Sperm design exerts a strong influence on sperm swimming speed, with faster swimming sperm having elongated heads, shorter midpieces and a longer principal plus terminal pieces in relation to total flagellum length. Thus, the large inter-male variation in sperm design found among natural populations underlies differences in sperm swimming speed which, in turn, determine differences in male fertility rates. Secondary sexual characters are honest indicators of male fertility, so males with large and elaborated antlers have larger testes and faster swimming sperm. Testosterone does not seem to mediate the relationship between antler size and semen quality, since it is associated with sperm production, but not with sperm quality or antler size. Finally, more fertile males produce a greater proportion of sons, who will inherit the semen traits which will enhance their fertility.

show abstract

“…Most available studies, conducted on samples from boar10, cattle1011121314 or humans151617, used inaccurate evaluation techniques such as fluorescence staining of the F-body or PCR amplification on pooled semen samples. Correlation between the ratio in the ejaculate and the birth sex ratio was found in those studies that made the comparison121617.…”

mentioning

confidence: 99%

Male pygmy hippopotamus influence offspring sex ratio

et al. 2012

View full text Add to dashboard Cite

Pre-determining fetal sex is against the random and equal opportunity that both conceptus sexes have by nature. Yet, under a wide variety of circumstances, populations shift their birth sex ratio from the expected unity. Here we show, using fluorescence in situ hybridization, that in a population of pygmy hippopotamus (Choeropsis liberiensis) with 42.5% male offspring, males bias the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates, resulting in a 0.4337±0.0094 (mean±s.d.) proportion of Y-chromosome-bearing spermatozoa. Three alternative hypotheses for the shifted population sex ratio were compared: female counteract male, female indifferent, or male and female in agreement. We conclude that there appears little or no antagonistic sexual conflict, unexpected by prevailing theories. Our results indicate that males possess a mechanism to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in the ejaculate, thereby substantially expanding currently known male options in sexual conflict.

show abstract

Collection frequency affects percent Y-chromosome bearing sperm, sperm head area and quality of bovine ejaculates

Cited by 31 publications

References 12 publications

Variation among Beef Bulls in the Ratio of X- to Y-Chromosome Bearing Spermatozoa

Variation among Beef Bulls in the Ratio of X- to Y-Chromosome Bearing Spermatozoa

Sperm traits and male fertility in natural populations

Male pygmy hippopotamus influence offspring sex ratio

Contact Info

Product

Resources

About