Female-limited X-chromosome evolution effects on male pre- and post-copulatory success

• Published in: Biology letters (2005) Vol. 17; no. 3; p. 20200915
• Main Authors: Manat, Yesbol, Lund-Hansen, Katrine K., Katsianis, Georgios, Abbott, Jessica K.
• Format: Journal Article
• Language: English
• Published: England The Royal Society 03.03.2021
• Subjects: Animals; Biologi; Biological Evolution; Biological Sciences; Body Size; Chromosomes; Drosophila melanogaster - genetics; Evolutionary Biology; Evolutionsbiologi; Female; intralocus sexual conflict; Male; male attractiveness; male fitness; Natural Sciences; Naturvetenskap; Reproduction; Selection, Genetic; Sex Characteristics; Sexual Behavior, Animal; sperm competition; X-chromosome; X-chromosome; sperm competition; intralocus sexual conflict; male attractiveness; male fitness
• ISSN: 1744-957X; 1744-9561; 1744-957X
• DOI: 10.1098/rsbl.2020.0915

Intralocus sexual conflict arises when the expression of shared alleles at a single locus generates opposite fitness effects in each sex (i.e. sexually antagonistic alleles), preventing each sex from reaching its sex-specific optimum. Despite its importance to reproductive success, the relative contribution of intralocus sexual conflict to male pre- and post-copulatory success is not well-understood. Here, we used a female-limited X-chromosome (FLX) evolution experiment in Drosophila melanogaster to limit the inheritance of the X-chromosome to the matriline, eliminating possible counter-selection in males and allowing the X-chromosome to accumulate female-benefit alleles. After more than 100 generations of FLX evolution, we studied the effect of the evolved X-chromosome on male attractiveness and sperm competitiveness. We found a non-significant increase in attractiveness and decrease in sperm offence ability in males expressing the evolved X-chromosomes, but a significant increase in their ability to avoid displacement by other males' sperm. This is consistent with a trade-off between these traits, perhaps mediated by differences in body size, causing a small net reduction in overall male fitness in the FLX lines. These results indicate that the X-chromosome in D. melanogaster is subject to selection via intralocus sexual conflict in males.