The complexities of female mate choice and male polymorphisms： Elucidating the role of genetics, age, and mate-choice copying

Genetic, life history, and environmental factors dictate patterns of variation in sexual traits within and across popula- tions, and thus the action and outcome of sexual selection. This study explores patterns of inheritance, diet, age, and mate-choice copying on the expression of male sexual signals and associated female mate choice in a phenotypically diverse group of Schizo- cosa wolf spiders. Focal spiders exhibit one of two male phenotypes： ＇omamented＇ males possess large black brushes on their fo- relegs, and ＇non-ornamented＇ males possess no brushes. Using a quantitative genetics breeding design in a mixed population of ornamented/non-ornamented males, we found a strong genetic basis to male phenotype and female choice. We also found that some ornamented males produced some sons with large brushes and others with barely visible brushes. Results of diet manipula- tions and behavioral mating trials showed no influence of diet on male phenotype or female mate choice. Age post maturation, however, influenced mate choice, with younger females being more likely to mate with ornamented males. A mate-choice copy- ing experiment found that, following observations of another female＇s mate choice/copulation, virgin mature females tended to match the mate choice （ornamented vs. non-ornamented males） of the females they observed. Finally, analyses of genetic varia- tion across phenotypically pure （only one male phenotype present） vs. mixed （both phenotypes present） populations revealed ge- netic distinction between phenotypes in phenotypically-pure populations, but no distinctionin phenotypically-mixed populations. The difference in patterns of genetic differentiation and mating across geographic locations suggests a complex network of fac- tors contributing to the outcome of sexual selection .

Association between MTHFR A1298C Polymorphism and Male Infertility：A Meta-analysis

There have been several epidemiological studies evaluating the potential association between the methylenetetrahydrofolate reductase（MTHFR） A1298 C polymorphism and the risk of male infertility.However,the results obtained were inconsistent.Therefore,we performed a meta-analysis to further examine the association between the MTHFR A1298 C polymorphism and male infertility.A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to January 15 th,2016.A total of 20 studies with 4293 cases and 4507 controls were included.An odds ratio（OR） and a 95% confidence interval（95% CI） were calculated to assess the strength of the association.A cumulative meta-analysis,sensitivity analysis and assessment of the publication bias were also performed in this study.The results showed that in the overall analysis,the association between the MTHFR A1298 C polymorphism and male infertility was not significant.A stratified analysis by ethnicity revealed a significant increase in the risk of male infertility in the Asian population with the MTHFR A1298 C polymorphism（especially in the heterozygote model：OR=1.20,95% CI=1.01–1.44,P=0.994;the dominant model：OR=1.23,95% CI=1.04–1.45,P=0.996;and the allele model：OR=1.20,95% CI=1.04–1.39,P=0.985） but not in the Caucasian population.In the stratified analyses,no significant association was observed between the different types of male infertility.This meta-analysis suggests the MTHFR A1298 C polymorphism may be a potential risk factor for male infertility,especially in the Asian population.

Glutathione S-transferase P1 IlelO5Val Polymorphism and Male Infertility Risk： An Updated Meta-analysis

Background： Several studies concerning the association between glutathione S-transferase P1 （GSTP1） Ilel05Val polymorphism and male infertility risk have reported controversial findings. The present study was aimed to explore this association using a recta-analysis. Methods： The PubMed, EMBASE, China National Knowledge Infrastructure （CNKI）, and Wanfang databases were searched. Odds ratios （ORs） with 95% confidence intervals （C/s） were calculated to estimate the strength of the association. Results： A total of 3282 cases and 3268 controls in nine case-control studies were included. There was no significant association between GSTP1 llel05Val polymorphism and male infertility in the overall population, but significant associations were lbund under the dominant （OR = 1.23, 95% CI = 1.04-1.46, F = 32.2%） and heterozygote （OR = 1.29, 95% C1 - 1.08-1.53, F = 26.8%） models after excluding studies for which the data did not satisfy Hardy-Weinberg equilibrium （HWE）. Similarly, subgroup analyses revealed no significant association in Asians or Chinese population although a significant association was apparent among Chinese population in studies with HWE under the heterozygote model （OR = 1.25, 95% CI = 1.03-1.52, F = 44.1%）. Significant heterogeneity could be observed in some genetic models, but this heterogeneity was not significant when stratified by HWE. No evidence for publication bias was found. Conclusions： The GS-FP1 lle105Val polymorphism might not be associated with male infertility risk, and thus additional well-designed studies with larger sample size are warranted.