Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability

The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection since drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths we show that the presence of one or two copies of the yellow allele affects several life-history traits. Reproductive output of both males and females, and female mating success are negatively affected by two copies of the yellow allele. Females carrying one yellow allele (i.e. Wy) have higher fertility, hatching success, and offsprin...种群内表型变异的维持通常依赖某种形式的平衡选择（balancing selection），因为遗传漂变与定向选择最终会清除种群内的遗传变异。杂合子优势（heterozygote advantage）一直是解释选择压力下遗传变异得以维持的经典机制。然而，除与抗病性（disease resistance）相关的案例外，杂合子优势的实际实例相当罕见。在其大部分分布范围内，警戒色蛾类星灯蛾（Arctia plantaginis）的雄性个体存在两种后翅表型，该性状由单基因双等位基因多态性（one locus-two allele polymorphism）遗传决定：基因型为WW/Wy的个体表现为白色型（white morph），基因型为yy的个体则表现为黄色型（yellow morph）。本研究通过对蛾类进行基因分型，证实黄色等位基因的单拷贝或双拷贝会对多项生活史性状（life-history traits）产生影响。携带两份黄色等位基因会对雌雄个体的繁殖产出（reproductive output）以及雌性的交配成功率（mating success）造成负面影响。携带一份黄色等位基因（即Wy基因型）的雌性个体，其受精率、孵化成功率及子代...