Linksvayer Timothy A
Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
Evolution. 2006 Dec;60(12):2552-61. doi: 10.1554/06-011.1.
When social interactions occur, the phenotype of an individual is influenced directly by its own genes (direct genetic effects) but also indirectly by genes expressed in social partners (indirect genetic effects). Social insect colonies are characterized by extensive behavioral interactions among workers, brood, and queens so that indirect genetic effects are particularly relevant. I used a series of experimental manipulations to disentangle the contribution of direct effects, maternal (queen) effects, and sibsocial (worker) effects to variation for worker, gyne, and male mass; caste ratio; and sex ratio in the ant Temnothorax curvispinosus. The results indicate genetic variance for direct, maternal, and sibsocial effects for all traits, except for male mass there was no significant maternal variance, and for sex ratio the variance for direct effects was not separable from maternal variance for the primary sex ratio. Estimates of genetic correlations between direct, maternal, and sibsocial effects were generally negative, indicating that these effects may not evolve independently. These results have broad implications for social insect evolution. For example, the genetic architecture underlying social insect traits may constrain the realization of evolutionary conflicts between social partners.
当社会互动发生时，个体的表型不仅直接受其自身基因影响（直接遗传效应），还间接受社会伙伴所表达基因的影响（间接遗传效应）。社会性昆虫群体的特点是工蚁、幼虫和蚁后之间存在广泛的行为互动，因此间接遗传效应尤为重要。我采用了一系列实验操作，以厘清直接效应、母体（蚁后）效应和同胞社会（工蚁）效应，对弯刺蚁工蚁、雌蚁和雄蚁的体重变化、品级比例以及性别比例的贡献。结果表明，所有性状在直接、母体和同胞社会效应方面均存在遗传方差，但雄蚁体重不存在显著的母体方差，而对于性别比例，直接效应的方差与初级性别比例的母体方差无法区分。直接、母体和同胞社会效应之间的遗传相关性估计通常为负，表明这些效应可能无法独立进化。这些结果对社会性昆虫的进化具有广泛影响。例如，社会性昆虫性状背后的遗传结构可能会限制社会伙伴之间进化冲突的实现。
