Genetic Background, Maternal Age, and Interaction Effects Mediate Rates of Crossing Over inDrosophila melanogasterFemales

Abstract

Meiotic recombination is a genetic process that is critical for proper chromosome segregation in many organisms. Despite being fundamental for organismal fitness, rates of crossing over vary greatly between taxa. Both genetic and environmental factors contribute to phenotypic variation in crossover frequency, as do genotype–environment interactions. Here, we test the hypothesis that maternal age influences rates of crossing over in a genotypic-specific manner. Using classical genetic techniques, we estimated rates of crossing over for individual Drosophila melanogaster females from five strains over their lifetime from a single mating event. We find that both age and genetic background significantly contribute to observed variation in recombination frequency, as do genotype–age interactions. We further find differences in the effect of age on recombination frequency in the two genomic regions surveyed. Our results highlight the complexity of recombination rate variation and reveal a new role of genotype by maternal age interactions in mediating recombination rate.

Wolbachia Infection Associated with Increased Recombination in Drosophila

“…That one genomic interval shows a plastic response to Wolbachia infection while another does not is also consistent with previous reports indicating variation in recombination plasticity across intervals in D. melanogaster (Hunter et al 2016b) and D. pseudoobscura (Stevison et al 2017). Interestingly, the e ro interval surveyed here has previously been shown to exhibit a plastic increase in recombination following infection with pathogenic bacteria and heat shock (Jackson et al 2015), but no plastic response to maternal age (Hunter et al 2016b). This suggests that genomic intervals may exhibit phenotypic plasticity in recombination in response to some environmental cues but not others.…”

Experimental evolution across different thermal regimes yields genetic divergence in recombination fraction but no divergence in temperature associated plastic recombination

“…Indeed, genotype‐environment interactions significantly contribute to recombination rate variation in D. melanogaster , for instance (Hunter et al. ). Second, the magnitude and direction of temperature‐associated plastic recombination may vary across the genome.…”

“…Differences in the genotypes of the strains used for experimentation may yield variable responses to temperature. Indeed, genotype-environment interactions significantly contribute to recombination rate variation in D. melanogaster, for instance (Hunter et al 2016b). Second, the magnitude and direction of temperature-associated plastic recombination may vary across the genome.…”

“…Similarly, exposure to parasites has been associated with elevated recombination rates (Andronic 2012;Singh et al 2015), and nutrient stress is associated with increased recombination rates in yeast (Abdullah and Borts 2001) and Drosophila (Neel 1941). Further, a clear link between maternal age and recombination rate has been found in humans (e.g., Kong et al 2004;Hussin et al 2011), mice (Henderson andEdwards 1968;Luthardt et al 1973) and Drosophila (Stern 1926;Bridges 1927;Redfield 1964;Lake 1984;Chadov et al 2000;Priest et al 2007;Tedman-Aucoin and Agrawal 2012;Hunter et al 2016b). Thus, meiotic recombination rate shows variability in the context of organismal development and across environments, making it an appropriate trait for exploring the evolution of and genetic architecture of phenotypic plasticity.…”

“…; Tedman‐Aucoin and Agrawal ; Hunter et al. ). Thus, meiotic recombination rate shows variability in the context of organismal development and across environments, making it an appropriate trait for exploring the evolution of and genetic architecture of phenotypic plasticity.…”