Nelson C Mindy, Ihle Kate E, Fondrk M Kim, Page Robert E, Amdam Gro V
Department of Entomology, University of California Davis, Davis, California, United States of America.
PLoS Biol. 2007 Mar;5(3):e62. doi: 10.1371/journal.pbio.0050062.
Temporal division of labor and foraging specialization are key characteristics of honeybee social organization. Worker honeybees (Apis mellifera) initiate foraging for food around their third week of life and often specialize in collecting pollen or nectar before they die. Variation in these fundamental social traits correlates with variation in worker reproductive physiology. However, the genetic and hormonal mechanisms that mediate the control of social organization are not understood and remain a central question in social insect biology. Here we demonstrate that a yolk precursor gene, vitellogenin, affects a complex suite of social traits. Vitellogenin is a major reproductive protein in insects in general and a proposed endocrine factor in honeybees. We show by use of RNA interference (RNAi) that vitellogenin gene activity paces onset of foraging behavior, primes bees for specialized foraging tasks, and influences worker longevity. These findings support the view that the worker specializations that characterize hymenopteran sociality evolved through co-option of reproductive regulatory pathways. Further, they demonstrate for the first time how coordinated control of multiple social life-history traits can originate via the pleiotropic effects of a single gene that affects multiple physiological processes.
时间分工和觅食专业化是蜜蜂社会组织的关键特征。工蜂(西方蜜蜂)在出生约第三周开始觅食,并且在死亡前通常专门采集花粉或花蜜。这些基本社会特性的变化与工蜂生殖生理的变化相关。然而,介导社会组织控制的遗传和激素机制尚不清楚,仍然是社会昆虫生物学中的核心问题。在此,我们证明一种卵黄前体基因——卵黄蛋白原,会影响一系列复杂的社会特性。一般来说,卵黄蛋白原是昆虫中的一种主要生殖蛋白,也是蜜蜂中一种假定的内分泌因子。我们通过RNA干扰(RNAi)表明,卵黄蛋白原基因活性决定了觅食行为的开始,使蜜蜂为专门的觅食任务做好准备,并影响工蜂寿命。这些发现支持了这样一种观点,即膜翅目社会性的工蜂专业化是通过生殖调控途径的共同选择进化而来的。此外,它们首次证明了多个社会生活史特征的协调控制是如何通过影响多个生理过程的单个基因的多效性效应产生的。