Sharp N P, Vincent C M
1] Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada [2] Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
Heredity (Edinb). 2015 Apr;114(4):367-72. doi: 10.1038/hdy.2014.110. Epub 2015 Feb 4.
The life history strategies of males and females are often divergent, creating the potential for sex differences in selection. Deleterious mutations may be subject to stronger selection in males, owing to sexual selection, which can improve the mean fitness of females and reduce mutation load in sexual populations. However, sex differences in selection might also maintain sexually antagonistic genetic variation, creating a sexual conflict load. The overall impact of separate sexes on fitness is unclear, but the net effect is likely to be positive when there is a large sex difference in selection against deleterious mutations. Parasites can also have sex-specific effects on fitness, and there is evidence that parasites can intensify the fitness consequences of deleterious mutations. Using lines that accumulated mutations for over 60 generations, we studied the effect of the pathogenic bacterium Pseudomonas aeruginosa on sex differences in selection in the fruit fly Drosophila melanogaster. Pseudomonas infection increased the sex difference in selection, but may also have weakened the intersexual correlation for fitness. Our results suggest that parasites may increase the benefits of sexual selection.
雄性和雌性的生活史策略往往不同，这就产生了选择中性别差异的可能性。由于性选择，有害突变在雄性中可能会受到更强的选择，这可以提高雌性的平均适应性并减少有性种群中的突变负荷。然而，选择中的性别差异也可能维持性拮抗基因变异，从而产生性冲突负荷。不同性别对适应性的总体影响尚不清楚，但当针对有害突变的选择存在较大性别差异时，净效应可能是积极的。寄生虫也会对适应性产生性别特异性影响，并且有证据表明寄生虫会加剧有害突变对适应性的影响。我们使用积累了60多代突变的品系，研究了病原菌铜绿假单胞菌对果蝇选择中性别差异的影响。铜绿假单胞菌感染增加了选择中的性别差异，但也可能削弱了适应性的两性相关性。我们的结果表明，寄生虫可能会增加性选择的益处。
