Data from: The transcriptomic and evolutionary signature of social interactions regulating honey bee caste development

The caste fate of developing female honey bee larvae is strictly socially regulated by adult nurse workers. As a result of this social regulation, nurse-expressed genes as well as larval-expressed genes may affect caste expression and evolution. We used a novel transcriptomic approach to identify genes with putative direct and indirect effects on honey bee caste development, and we subsequently studied the relative rates of molecular evolution at these caste-associated genes. We experimentally induced the production of new queens by removing the current colony queen, and we used RNA sequencing to study the gene expression profiles of both developing larvae and their caregiving nurses before and after queen removal. By comparing the gene expression profiles of queen-destined versus worker-destined larvae as well as nurses observed feeding these two types of larvae, we identified larval and nurse genes associated with caste development. Of 950 differentially expressed genes associated with caste, 82% were expressed in larvae with putative direct effects on larval caste, and 18% were expressed in nurses with putative indirect effects on caste. Estimated selection coefficients suggest that both nurse and larval genes putatively associated with caste are rapidly evolving, especially those genes associated with worker development. Altogether, our results suggest that indirect effect genes play important roles in both the expression and evolution of socially influenced traits such as caste.

发育中的雌性蜜蜂幼虫的品级命运严格由成年哺育蜂进行社会性调控。受此社会性调控机制影响，哺育蜂表达基因与幼虫表达基因均可能参与调控蜜蜂品级的表型表达与演化进程。本研究采用一种新型转录组学方法，筛选出对蜜蜂品级发育具有潜在直接与间接调控作用的基因，随后对这些与品级相关基因的分子进化相对速率展开分析。我们通过移除蜂群现有蜂王的方式，实验性诱导新蜂王的产生；并借助RNA测序技术，分析了蜂王移除前后，发育中的幼虫及其照料的哺育蜂的基因表达谱。通过对比将发育为蜂王与工蜂的幼虫，以及饲喂这两类幼虫的哺育蜂的基因表达谱，我们筛选出了与品级发育相关的幼虫基因与哺育蜂基因。在950个与品级相关的差异表达基因中，82%在幼虫中表达，对幼虫品级发育具有潜在直接调控作用；剩余18%在哺育蜂中表达，对品级发育发挥潜在间接调控作用。估算得到的选择系数显示，所有潜在与品级相关的哺育蜂基因与幼虫基因均呈现快速演化特征，其中与工蜂发育相关的基因演化速度尤为显著。综合来看，本研究结果表明，间接调控基因在诸如品级这类受社会性影响的性状的表型表达与演化过程中，均发挥着关键作用。