Recipe for a Busy Bee: MicroRNAs in Honey Bee Caste Determination

Xiangqian Guo,Fang Liu,Wenfeng Li,Yu Guo,Geir Skogerboe,Runsheng Chen,Shenglu Chen,Ruifeng Ni,Songkun Su,Shuanjin Dai,Shaowu Zhang,Zhiguo Li

doi:10.1371/journal.pone.0081661

Abstract

Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed Illumina/Solexa sequencing to examine the small RNA content in the bee larval food, and show that worker jelly is enriched in miRNA complexity and abundance relative to royal jelly. The miRNA levels in worker jelly were 7–215 fold higher than in royal jelly, and both jellies showed dynamic changes in miRNA content during the 4th to 6th day of larval development. Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.

Highlights

Eusocial insects, of which the honey bee is the most extensively/ intensively researched species, are unusual in the sense that the female exists as two phenotypes derived from the same genotypic background [1]
Female caste determination has traditionally been ascribed to special properties of royal jelly, which is fed in copious amounts to prospective queen bee larvae, thereby ensuring attainment of the royal status, whereas the less sophisticated diet enjoyed by the rest of the brood leads to the worker bee fate [2]
The results show that the honey bee larval food contains distinct differences in miRNA levels

Summary

Introduction

Of which the honey bee is the most extensively/ intensively researched species, are unusual in the sense that the female exists as two (or in some cases, several) phenotypes derived from the same genotypic background [1]. The worker is designed for and carries out, most functions normally assigned to motherhood, such as nest-building, feeding and caring for the brood, guarding and foraging. Female caste determination has traditionally been ascribed to special properties of royal jelly, which is fed in copious amounts to prospective queen bee larvae, thereby ensuring attainment of the royal status, whereas the less sophisticated diet enjoyed by the rest of the brood leads to the worker bee fate [2].

Methods

Results

Conclusion