On the genetic architecture of rapidly adapting and convergent life history traits in guppies

The genetic basis of traits shapes and constrains how adaptation proceeds in nature; rapid adaptation can be facilitated by polygenic traits, which subsequently provide multiple, redundant, genetic routes to adaptive phenotypes, reducing re-use of the same genes (genetic convergence). Guppy life history traits evolve rapidly and convergently among natural high- (HP) and low-predation (LP) environments in northern Trinidad. This system has been studied extensively at the phenotypic level, but little is known about the underlying genetic architecture. Here, we use an F2 QTL design to examine the genetic basis of seven (five female, two male) guppy life history phenotypes to assess whether the genetic architecture of these traits reflects theoretical predictions. We use RAD-sequencing data (16,539 SNPs) from 370 male and 267 female F2 individuals. We perform linkage mapping, estimates of genome-wide and per-chromosome heritability (multi-locus associations), and QTL ma pping (single-locus ...

性状的遗传基础塑造并制约了自然界中适应性演化的进程；多基因性状可助力快速适应性演化，此类性状后续能够提供多条冗余的遗传路径以产生适应性表型，进而减少同一基因的重复使用（遗传趋同，genetic convergence）。特立尼达北部自然生境中，高捕食压力（HP, high-predation）与低捕食压力（LP, low-predation）环境下的孔雀鱼生活史性状会发生快速且趋同的演化。该研究体系已在表型层面得到广泛探索，但学界对其背后的遗传架构仍知之甚少。本研究采用F2群体数量性状基因座（QTL, quantitative trait locus）设计，针对7项孔雀鱼生活史表型（其中雌性5项、雄性2项）的遗传基础展开分析，以验证这些性状的遗传架构是否契合理论预测。我们对370只雄性与267只雌性F2个体进行限制性位点关联DNA测序（RAD-sequencing），共获得16539个单核苷酸多态性位点（SNPs, single nucleotide polymorphism）。我们将开展连锁作图、全基因组及染色体水平遗传力估算（多基因座关联分析）以及数量性状基因座作图（单基因座……）