Gene expression response to irradiation and social environments in the reproductive tracts of male seed beetles, Callosobruchus maculatus. Gene expression response to irradiation and social environments in the reproductive tracts of male seed beetles, Callosobruchus maculatus

We studied the effect of social environment (presence of conspecific males and/or females) and gamma irradiation on gene expression in the male reproductive tract (aedeagus, ejaculatory bulb, 2 bilobed testes and 3 pairs of smaller accessory glands; the two pairs of larger accessory glands were removed) in a full factorial design. Overall design: The experiment was replicated in two lines (MA1 & MA3) and over two days, resulting in 4 replicate samples per irradiation/social environment combination. Both lines are experimental evolution lines evolved under intense sexual selection with natural selection removed (Baur and Berger, 2020, Nature Ecology and Evolution 4, 737-744, https://doi.org/10.1038/s41559-020-1140-7). Males were held in one of four social environments (virgin: alone, mated: with one conspecific female, male-male: in groups of 5 conspecific males, mixed: in groups of 5 conspecific males and 5 conspecific females) for 24 hours. Afterwards males were isolated and either irradiated (a dose of 25 Gray of gamma radiation from a caesium-137 source over 35 min) or kept as controls. After a 2 hour recovery period males were flash-frozen and stored at -80 °C until dissections. Per sample, we pooled the reproductive tracts from 9-10 males within each line/day/treatment combination resulting in a total of 32 samples.