One QTL for intra- and interspecific variation in a sex pheromone

Even though premating isolation is hypothesized to be a major driving force in speciation, its genetic basis is poorly known. In the noctuid moth Heliothis subflexa, one group of sex pheromone components, the acetates, emitted by the female, plays a crucial isolating role in preventing interspecific matings to males of the closely related Heliothis virescens, in which females do not produce acetates and males are repelled by them. We previously found intraspecific variation in acetates in H. subflexa: females in eastern North America contain significantly more acetates than females in Western Mexico. Here we describe the persistence of this intraspecific variation in laboratory-reared strains and the identification of one major quantitative trait locus (QTL), explaining 40% of the variance in acetate amounts. We homologized this intraspecific QTL to our previously identified interspecific QTL using restriction-associated DNA (RAD) tags. We found that a major intraspecific QTL overlaps w...尽管交配前生殖隔离（premating isolation）被假说为物种形成的主要驱动力，但其遗传基础仍鲜为人知。在夜蛾科昆虫烟实夜蛾（Heliothis subflexa）中，雌性分泌的一类性信息素组分——乙酸酯类（acetates），在阻止与近缘种烟芽夜蛾（Heliothis virescens）雄性的种间交配中发挥关键隔离作用；该近缘种的雌性不产生乙酸酯类，且其雄性会被乙酸酯类驱避。我们此前已发现烟实夜蛾的乙酸酯类存在种内变异：北美东部的雌性个体所含乙酸酯类量显著高于墨西哥西部的雌性个体。本研究首先描述了该种内变异在实验室饲养品系中的持续性，并鉴定出一个主效数量性状位点（QTL），该位点可解释乙酸酯类含量变异的40%。我们通过限制性酶切相关DNA（RAD）标签，将该种内QTL与我们此前鉴定的种间QTL进行同源性比对，发现一个主要的种内QTL与……