Intralocus sexual conflict and environmental stress

Intralocus sexual conflict (ISC) occurs when selection at a given locus favors different alleles in males and females, placing a fundamental constraint on adaptation. However, the relative impact of ISC on adaptation may become reduced in stressful environments that expose conditionally deleterious mutations to selection. The genetic correlation for fitness between males and females (rMF) provides a quantification of ISC across the genome. We compared ISC at a benign (29˚C) and a stressful (36˚C) temperature by estimating rMFs in two natural populations of the seed beetle Callosobruchus maculatus using isofemale lines. In one population, we found substantial ISC under benign conditions signified by a negative rMF (-0.51) and, as predicted, a significant reduction of ISC under stress signified by a reversed and positive rMF (0.21). The other population displayed low ISC at both temperatures (rMF: 0.38; 0.40). In both populations, isofemale lines harboring alleles beneficial to males but ...基因座内性别冲突（Intralocus sexual conflict, ISC）指当特定基因座上的选择对雄性和雌性偏好不同的等位基因时，会对适应过程构成根本性约束。然而，在可使条件性有害突变暴露于选择作用的胁迫环境中，ISC对适应的相对影响或可减弱。雌雄个体间的适合度遗传相关（rMF）可量化全基因组范围内的ISC强度。本研究以两种自然种群的绿豆象（Callosobruchus maculatus）为研究对象，通过同雌系（isofemale lines）估算rMF，进而对比了适宜温度（29℃）与胁迫温度（36℃）下的ISC水平。在其中一个种群中，适宜条件下存在显著的ISC，表现为负向rMF（-0.51）；而正如预期，胁迫条件下ISC显著减弱，rMF反转呈正值（0.21）。另一个种群在两种温度下均表现出较弱的ISC，rMF分别为0.38与0.40。在两个种群中，携带对雄性有益等位基因的同雌系……