Abstract

Experimental evolution in combination with whole genome sequencing offers the unique opportunity to study adaptive processes under controlled, replicated conditions. Modifying the experimental protocol in combination with time series data, we obtain very localized selection signatures in D. simulans populations adapting to a new temperature regime. Combining genomic signatures with expression analyses we study two different evolutionary processes and link them to natural populations. First, we analyze the metabolic rewiring during adaptation in the laboratory. We identify AMPK , a central metabolic switch, as a key player in the laboratory. Linking the experimental evolution results to clinal variation in natural populations, we show that AMPK is not only among the genes with the largest clinal variation, but populations from the extreme ends of the cline differ also in their expression pattern. As a second evolutionary process we study the invasion of the P-element into D. simulans. We show that the speed of the P-element invasion is triggered by temperature-specific expression of the P-element. In the hot environment, the spread of the P-element is already completed after about 20 generations. We show that at this time point piRNA-meditated defense has been established, which are prevents a further increase in P-element copy number. Hence, similar to natural populations the P-element spread is controlled by piRNAs.