Variation inDrosophila melanogastercentral metabolic genes appears driven by natural selection both within and between populations

Abstract

In this report, we examine the hypothesis that the drivers of latitudinal selection observed in the eastern US Drosophila melanogaster populations are reiterated within seasons in a temperate orchard population in Pennsylvania, USA. Specifically, we ask whether alleles that are apparently favoured in northern populations are also favoured early in the spring, and decrease in frequency from the spring to autumn with the population expansion. We use SNP data collected for 46 metabolic genes and 128 SNPs representing the central metabolic pathway and examine for the aggregate SNP allele frequencies whether the association of allele change with latitude and that with increasing days of spring-autumn season are reversed. Testing by random permutation, we observe a highly significant negative correlation between these associations that is consistent with this expectation. This correlation is stronger when we confine our analysis to only those alleles that show significant latitudinal changes. This pattern is not caused by association with chromosomal inversions. When data are resampled using SNPs for amino acid change the relationship is not significant but is supported when SNPs associated with cis-expression are only considered. Our results suggest that climate factors driving latitudinal molecular variation in a metabolic pathway are related to those operating on a seasonal level within populations.

Dietary choices are influenced by genotype, mating status, and sex in Drosophila melanogaster

“…One study has found season-dependent oscillating patterns of allele frequency change of central metabolic and nutrient sensing genes (Cogni et al, 2015). than all previous studies (~42%: yeast extract) and thus our study is more informative about the effects of protein on dietary preference.…”

Genetic perturbation of key central metabolic genes extends lifespan in Drosophila and affects response to dietary restriction

“…Moreover, these activity differences are representative of the range of much of the cis-associated SNP expression variation seen in natural populations [34,38]. The observation that metabolic genes, when perturbed modestly in activity, have an effect on lifespan is certainly relevant to discussions of the maintenance of genetic variation in these genes in natural populations, especially as nutrient levels vary geographically and seasonally [38,39].…”

“…In D. melanogaster, the genes of the central metabolic pathway harbour considerable sequence and expression variation [34][35][36], which often shows change with latitude and season [37][38][39]. In this regard, unlike the other experimental models used in aging studies, Drosophila offers the unique opportunity to associate aging and signalling pathways with their population genetics [40,41].…”

Phenotypic plasticity, but not adaptive tracking, underlies seasonal variation in post‐cold hardening freeze tolerance of Drosophila melanogaster

“…Populations of flies living in orchards evolve over the period of months (Bergland, Behrman, O'Brien, Schmidt, & Petrov, 2014) as they track changing fitness optima influenced by seasonal fluctuations in selection pressure (Machado et al, 2018). Although many life-history and stress tolerance traits have been shown to exhibit adaptive tracking across short timescales (e.g., Behrman et al, 2018;Behrman et al, 2015;Cogni et al, 2014Cogni et al, , 2015, some of these traits are also highly plastic (e.g., Ayrinhac et al, 2004;Chippindale, Leroi, Kim, & Rose, 2004).…”