Wheeler Marsha M, Ament Seth A, Rodriguez-Zas Sandra L, Southey Bruce, Robinson Gene E
Department of Entomology, UIUC, Urbana, IL 61801, USA.
Institute for Systems Biology, Seattle, WA 98109, USA.
J Exp Biol. 2015 Dec;218(Pt 24):4005-14. doi: 10.1242/jeb.119420. Epub 2015 Nov 13.
Nervous and neuroendocrine systems mediate environmental conditions to control a variety of life history traits. Our goal was to provide mechanistic insights as to how neurosecretory signals mediate division of labor in the honey bee (Apis mellifera). Worker division of labor is based on a process of behavioral maturation by individual bees, which involves performing in-hive tasks early in adulthood, then transitioning to foraging for food outside the hive. Social and nutritional cues converge on endocrine factors to regulate behavioral maturation, but whether neurosecretory systems are central to this process is not known. To explore this, we performed transcriptomic profiling of a neurosecretory region of the brain, the pars intercerebralis (PI). We first compared PI transcriptional profiles for bees performing in-hive tasks and bees engaged in foraging. Using these results as a baseline, we then performed manipulative experiments to test whether the PI is responsive to dietary changes and/or changes in juvenile hormone (JH) levels. Results reveal a robust molecular signature of behavioral maturation in the PI, with a subset of gene expression changes consistent with changes elicited by JH treatment. In contrast, dietary changes did not induce transcriptomic changes in the PI consistent with behavioral maturation or JH treatment. Based on these results, we propose a new verbal model of the regulation of division of labor in honey bees in which the relationship between diet and nutritional physiology is attenuated, and in its place is a relationship between social signals and nutritional physiology that is mediated by JH.
神经和神经内分泌系统介导环境条件以控制多种生活史特征。我们的目标是提供关于神经分泌信号如何介导蜜蜂（西方蜜蜂）劳动分工的机制性见解。工蜂的劳动分工基于个体蜜蜂的行为成熟过程，这包括在成年早期执行蜂巢内任务，然后过渡到在蜂巢外觅食。社会和营养线索汇聚于内分泌因素以调节行为成熟，但神经分泌系统是否是这一过程的核心尚不清楚。为了探究这一点，我们对大脑的一个神经分泌区域——脑间部（PI）进行了转录组分析。我们首先比较了执行蜂巢内任务的蜜蜂和从事觅食的蜜蜂的PI转录谱。以这些结果为基线，我们随后进行了操纵实验，以测试PI是否对饮食变化和/或保幼激素（JH）水平的变化有反应。结果揭示了PI中行为成熟的强大分子特征，其中一部分基因表达变化与JH处理引起的变化一致。相比之下，饮食变化并未在PI中诱导出与行为成熟或JH处理一致的转录组变化。基于这些结果，我们提出了一种关于蜜蜂劳动分工调节的新文字模型，其中饮食与营养生理学之间的关系减弱，取而代之的是由JH介导的社会信号与营养生理学之间的关系。
