For almost a decade we have had a female-limited X chromosome evolution experiment running in our lab, and during this long-term experiment some interesting and unexpected things popped up. We started the evolution experiment to investigate intralocus sexual conflict on the X chromosome in Drosophila melanogaster. To do so we forced the inheritance of the X through females only, to investigate what happens to a number of phenotypic traits when male selection on the X is removed. We were able to enforce matrilineal inheritance by using an X chromosome balancer (FM), which has multiple inversions so it cannot recombine with the selected X but should still function as a normal X chromosome. However, it became clear almost from the start of the evolution experiment that the FM did not function completely like a normal X chromosome, due in part to the phenotypic markers it carries. We specifically found a large negative effect on male reproductive fitness when carrying the FM, which made us curious to investigate if we could find signs of compensatory selection on the autosomes, to counter this decrease in male fitness. To do so, we swapped the sex chromosomes and autosomes between the selection regime and the wildtype control, and between the FM balancer control and the wildtype control. This was done after 170 generations. The aim of this experiment was to disentangle the effects of the evolved autosomes and the evolved X chromosome, for example if changes on the autosomes tended to cancel out changes on the evolved X. We have already measured a few key phenotypic traits and are now specifically interested in detecting changes in expression data using RNAseq. The student who selects this project will therefore have the opportunity to work with expression data from Drosophila and compare the various genotypes.
We are looking for a student with bioinformatic skills, who also have good understanding and interest in evolutionary processes.
Duration: 15 or 30 credits:
Start time: Spring 2024
Contact: Katrine Lund-Hansen, Katrine.Lund-Hansen@biol.lu.se