Functional genomics of reproduction and division of labor in a key non-Apis pollinator

Abstract

i. List the original objectives, as defined in the approved proposal, and any revisions made at the beginning or during the course of project. Our objectives were: 1) develop state-of-the-art functional genomics tools for B. terrestris. These resources will be then used to: 2) characterize genes and molecular pathways that are associated with reproduction, 3) characterize genes and molecular pathways associated with specialization in foraging or nursing activities, and 4) determine the extent to which juvenile hormone (JH) is involved in the regulation of reproduction and division of labor. 5) Use RNA interference to down regulate genes associated with reproductive physiology, division of labor, or both. A decrease in the cost of RNA sequencing enabled us to further use the BARD support to extend our research to three additional related projects: A) The regulation of body size which is crucial for understanding both reproduction (castedetermination) and (size based) division of labor in bumblebees. B) Analyze RNA editing in our RNA sequencing data which improves the molecular understanding of the systems we study. C) The influence of JH on the fat body in addition to the brain on which we focused in our proposal. The fat body is a key tissue regulating insect reproduction and health. ii. Background to the topic. Bees are by far the most important pollinators in agricultural and natural ecosystems. The recent collapse of honey bee populations, together with declines in wild bee (including bumble bee) populations, puts their vital pollination services under severe threat. A promising strategy for circumventing this risk is the domestication and mass-rearing of non-Apis bees. This approach has been successfully implemented for several bumble bees including Bombusterrestris in Israel, and B. impatiens in the US, which are mass-reared in captivity. In spite of their critical economic and environmental value, little is known about the physiology and molecular biology of bumble bees. In this collaborative project we developed functional genomics tools for the bumble bee B. terrestris and use these tools for a first thorough study on the physiology and molecular biology of reproduction, dominance, and division of labor in a bumble bee. iii. Major conclusions, solutions. The valuable molecular data of this project together with the functional tools and molecular information generated in this BARD funded project significantly advanced the understanding of bumblebee biology which is essential for maintaining their vital pollination services for US and Israel agriculture.