Broad geographic sampling reveals the shared basis and environmental correlates of seasonal adaptation in Drosophila

Abstract

To advance our understanding of adaptation to temporally varying selection pressures, we identified signatures of seasonal adaptation occurring in parallel among Drosophila melanogaster populations. Specifically, we estimated allele frequencies genome-wide from flies sampled early and late in the growing season from 20 widely dispersed populations. We identified parallel seasonal allele frequency shifts across North America and Europe, demonstrating that seasonal adaptation is a general phenomenon of temperate fly populations. Seasonally fluctuating polymorphisms are enriched in large chromosomal inversions and we find a broad concordance between seasonal and spatial allele frequency change. The direction of allele frequency change at seasonally variable polymorphisms can be predicted by weather conditions in the weeks prior to sampling, linking the environment and the genomic response to selection. Our results suggest that fluctuating selection is an important evolutionary force affecting patterns of genetic variation in Drosophila.

A Population Genomic Assessment of Three Decades of Evolution in a Natural Drosophila Population

“…Our results are mostly in line with Kapun et al (2016) , who also described significant seasonal differences in In(2R)NS and In(3R)P , but not In(3R)Mo , from eastern US populations. Whereas, Machado et al (2021) analyzed the association between seasonally variable SNPs and inversion breakpoint regions, finding significant associations for In(2L)t and for a set of three inversions on arm 3R, but not for In(2R)NS.…”

“…A study by Bergland et al (2014) found evidence for dozens of genomic loci showing seasonal allele frequency changes in D. melanogaster that could not be explained by drift alone. Subsequent studies have expanded on those findings by leveraging seasonal population genomic data across multiple years from dozens of locations ( Kapun et al 2020 ; Machado et al 2021 ). Researchers have also sequenced museum specimens of the North American honeybee to study genomic changes in response to the introduction of a parasitic mite across roughly 50 generations ( Mikheyev et al 2015 ).…”

Neuroendocrine Regulation of Reproductive Dormancy in the Fruit Fly Drosophila melanogaster: A Review of Juvenile Hormone-Dependent Regulation

“…As described earlier, geological differences of genetic bias influence reproductive dormancy in D. melanogaster. Indeed, previous studies have shown that geographic variations in reproductive dormancy in wild D. melanogaster is associated with single nucleotide polymorphisms in the loci of tim, InR, FoxO, and couch potato (Williams et al, 2006;Sandrelli et al, 2007;Tauber et al, 2007;Paaby et al, 2010Paaby et al, , 2014Kolaczkowski et al, 2011;Lee et al, 2011;Fabian et al, 2012;Bergland et al, 2014;Kapun et al, 2016;Zhao et al, 2016;Betancourt et al, 2021;Machado et al, 2021). In the case of tim, it is hypothesized that the allelic frequencies of two distinct isoforms, ls-tim and s-tim (Rosato et al, 1997), may have evolved to cope with winter when D. melanogaster expanded into Europe (Tauber et al, 2007).…”

“…In the wild, it has been well described that there are geographic variations in reproductive dormancy in D. melanogaster (Williams et al, 2006;Tauber et al, 2007;Sandrelli et al, 2007;Schmidt and Paaby, 2008;Emerson et al, 2009b;Kolaczkowski et al, 2011;Lee et al, 2011;Fabian et al, 2012;Bergland et al, 2014;Kapun et al, 2016;Zhao et al, 2016;Zonato et al, 2017;Lirakis et al, 2018;Betancourt et al, 2021;Machado et al, 2021). D. melanogaster originated in sub-Saharan Africa and subsequently expanded its habitat, possibly in association with humans and agriculture (Flatt, 2020).…”

The Effects of Essential and Non-Essential Metal Toxicity in the Drosophila melanogaster Insect Model: A Review

“…Metal toxicity can be induced simply by adding metals to fly food. Populations of D. melanogaster can be found across the globe allowing investigation of local adaptations and diversity [ 14 , 15 , 16 , 17 , 18 , 19 ]. Further, the small size and easy care of D. melanogaster translates into large sample sizes that include males, females, and a diversity of genetic backgrounds.…”