BioProject

Purpose: House fly has a stable polygenic sex determination system. The male determining factor (Mdmd) is commonly found on the Y chromosome (Y^M) or the third chromosome (III^M). More...

Purpose: House fly has a stable polygenic sex determination system. The male determining factor (Mdmd) is commonly found on the Y chromosome (Y^M) or the third chromosome (III^M). These proto-Y chromosomes are clinally distributed, with Y^M found most commonly in northern latitudes and III^M most commonly found at southern latitudes, hinting at possible genotype-by-temperature interactions that maintain the polymorphism. If this distribution is maintained by temperature-dependent selection pressures, we expect the fitness of III^M and Y^M flies to vary across developmental temperatures. These temperature-dependent effects could be driven by differential gene expression in III^M and Y^M males at different temperatures. Here, we performed RNA-seq experiments to study how genotype-by-temperature interactions affect gene expression in male houseflies carrying different proto-Y chromosomes. Methods: We raised a Y^M strain known as IsoCS and a III^M strain known as CSrab at 18°C and 29°C for two generations. We dissected 5 heads and 15-20 pairs of testes for each of three replicates of each genotype-by-temperature combination. We carried out RNA-seq on these tissues. Results: We identified 247 genes whose expression in testis and 50 genes whose expression in head depends on genotype-by-temperature interactions. Overall design: We carried out RNA-seq on head and testis from two isogenic strains differing only in their proto-Y chromosomes, raised at two different developmental temperatures. We used three biological replicates for each tissue type at each temperature. Less...