de Castro Barbosa Rodrigues Barata, CarolinaISTA; Snook, Rhonda R.; Ritchie, Michael G.; Kosiol, Carolin
Experimental evolution studies are powerful approaches to examine the evolutionary history of lab populations. Such studies have shed light on how selection changes phenotypes and genotypes. Most of these studies have not examined the time course of adaptation under sexual selection manipulation, by resequencing the populations’ genomes at multiple time points. Here, we analyze allele frequency trajectories in Drosophila pseudoobscura where we altered their sexual selection regime for 200 generations and sequenced pooled populations at 5 time points. The intensity of sexual selection was either relaxed in monogamous populations (M) or elevated in polyandrous lines (E). We present a comprehensive study of how selection alters population genetics parameters at the chromosome and gene level. We investigate differences in the effective population size—Ne—between the treatments, and perform a genome-wide scan to identify signatures of selection from the time-series data. We found genomic signatures of adaptation to both regimes in D. pseudoobscura. There are more significant variants in E lines as expected from stronger sexual selection. However, we found that the response on the X chromosome was substantial in both treatments, more pronounced in E and restricted to the more recently sex-linked chromosome arm XR in M. In the first generations of experimental evolution, we estimate Ne to be lower on the X in E lines, which might indicate a swift adaptive response at the onset of selection. Additionally, the third chromosome was affected by elevated polyandry whereby its distal end harbors a region showing a strong signal of adaptive evolution especially in E lines.
Genome biology and evolution
This work was supported by the Vienna Science and Technology Fund (WWTF)(10.47379/MA16061). C.K. received funding from the Royal Society (RG170315) and the Carnegie Trust (RIG007474). M.G.R. and R.R.S. have been supported by NERC (UK) grants NE/I014632/1 and NE/V001566/1. Bioinformatics analyses were performed on the computer cluster at the University of St Andrews Bioinformatics Unit, which is funded by Wellcome Trust ISSF awards 105621/Z/14/Z. Complementary data parsing was carried out with the computational resources provided by the Research/Scientific Computing teams at The James Hutton Institute and the National Institute of Agricultural Botany (NIAB)—UK’s Crop Diversity Bioinformatics HPC, BBSRC grant BB/S019669/1. We are thankful to Paris Veltsos and R. Axel W. Wiberg for useful discussions about the project as well as providing us with the resequencing data they had produced as a result of previous work on this experiment. We are especially grateful to Tanya Sneddon for her help with the DNA extraction process and shipping.
de Castro Barbosa Rodrigues Barata C, Snook RR, Ritchie MG, Kosiol C. Selection on the fly: Short-term adaptation to an altered sexual selection regime in Drosophila pseudoobscura. Genome biology and evolution. 2023;15(7). doi:10.1093/gbe/evad113
de Castro Barbosa Rodrigues Barata, C., Snook, R. R., Ritchie, M. G., & Kosiol, C. (2023). Selection on the fly: Short-term adaptation to an altered sexual selection regime in Drosophila pseudoobscura. Genome Biology and Evolution. Oxford Academic. https://doi.org/10.1093/gbe/evad113
Castro Barbosa Rodrigues Barata, Carolina de, Rhonda R. Snook, Michael G. Ritchie, and Carolin Kosiol. “Selection on the Fly: Short-Term Adaptation to an Altered Sexual Selection Regime in Drosophila Pseudoobscura.” Genome Biology and Evolution. Oxford Academic, 2023. https://doi.org/10.1093/gbe/evad113.
C. de Castro Barbosa Rodrigues Barata, R. R. Snook, M. G. Ritchie, and C. Kosiol, “Selection on the fly: Short-term adaptation to an altered sexual selection regime in Drosophila pseudoobscura,” Genome biology and evolution, vol. 15, no. 7. Oxford Academic, 2023.
de Castro Barbosa Rodrigues Barata C, Snook RR, Ritchie MG, Kosiol C. 2023. Selection on the fly: Short-term adaptation to an altered sexual selection regime in Drosophila pseudoobscura. Genome biology and evolution. 15(7), evad113.
de Castro Barbosa Rodrigues Barata, Carolina, et al. “Selection on the Fly: Short-Term Adaptation to an Altered Sexual Selection Regime in Drosophila Pseudoobscura.” Genome Biology and Evolution, vol. 15, no. 7, evad113, Oxford Academic, 2023, doi:10.1093/gbe/evad113.
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