Post-copulatory success is a trade-off against pre-copulatory success

In this project, we are studying the nature of X-linked sexually antagonistic loci by doing a female-limited X chromosome (FLX) experimental evolution in a laboratory-adapted population of D. melanogaster. we predict that expressing the experimentally evolved X chromosome in the selected sex will result in more feminized phenotype expression of shared traits. There are four replicate populations of each of three experimental treatments: Female-limited X-chromosome (FLX), control wild type (Cwt), and a methodological control treatment to control for the confounding effect of the FM balancer chromosomein the FLX populations (CFM).The CFM treatment is handled in the same way as the FLX treatment, except that the X chromosome goes through repeating cycles of two generations in females followed by one generation in males.The mating attractiveness: This experiment was done in 12 blocks within a day, with 20 flies per replicate population per treatment in each block, estimating attractiveness of a total of 80 males per treatment.The sperm compitation: At generation 143, these tests were performed in 15 replicates per treatment per replicate population. In total, 360 test tubes of offspring were scored. The body size: Body size was estimated using measurements of thorax length. On day 13 from oviposition, 20 flies from each genotype were placed in 95 % ethanol. Air-dried flies were measured using a Nikon SMZ800 dissecting microscope at 63x magnification fitted with an eyepiece graticule. This assay was done at generations 18 and 72.