Sex-specific allelic transmission bias suggests sexual conflict at MC1R

Sexual conflict arises when selection in one sex causes the displacement of the other sex from its phenotypic optimum, leading to an inevitable tension within the genome – called intralocus sexual conflict. Although the autosomal melanocortin-1-receptor gene (MC1R) can generate colour variation in sexually dichromatic species, most previous studies have not considered the possibility that MC1R may be subject to sexual conflict. In the barn owl (Tyto alba), the allele MC1RWHITE is associated with whitish plumage coloration, typical of males, and the allele MC1RRUFOUS is associated with dark rufous coloration, typical of females, although each sex can express any phenotype. Because each colour variant is adapted to specific environmental conditions, the allele MC1RWHITE may be more strongly selected in males and the allele MC1RRUFOUS in females. We therefore investigated whether MC1R genotypes are in excess or deficit in male and female fledglings compared with the expected Hardy–Weinberg...性冲突指某一性别的选择作用使另一性别的表型最优值发生偏离，进而引发基因组内不可避免的张力，该现象被称为位点内性冲突（intralocus sexual conflict）。尽管常染色体黑皮质素-1受体基因（melanocortin-1-receptor gene, MC1R）可在两性异形物种中诱发体色变异，但既往绝大多数研究未考虑MC1R可能受到性冲突作用的可能性。在仓鸮（Tyto alba）中，MC1R等位基因MC1RWHITE与雄性典型的白色羽色相关联，MC1RRUFOUS等位基因则与雌性典型的深红褐色羽色相关联，不过两性均可表达任意一种羽型。鉴于每种羽色变异均适配特定的环境条件，MC1RWHITE等位基因在雄性中或受到更强的选择压力，而MC1RRUFOUS等位基因则在雌性中更受选择青睐。据此，我们开展了相关研究，旨在探究相较于哈迪-温伯格（Hardy–Weinberg）预期的基因型频率，MC1R基因型在雄性与雌性离巢幼鸟中是否存在过剩或缺失的情况……