Project description:We used RNA-se to compare gene expression patterns in workers of the bumble bee Bombus impatiens in response to the queen, the brood, both or none.
Project description:During the nest-founding phase of the bumble bee colony cycle, queens undergo striking changes in maternal care behavior. Early in the founding phase, prior to the emergence of workers in the nest, queens are reproductive and also provision and feed their offspring. However, later in the founding phase, queens cease feeding offspring and become specialized on reproduction. This transition is synchronized with the emergence of workers in the colony, who assume the task of feeding their siblings. Using a social manipulation experiment, we tested the hypothesis that workers socially regulate the transition from feeding brood to specialization on reproduction in nest-founding bumble bee queens. Consistent with this hypothesis, we found that early-stage queens with workers prematurely added to their nests reduce their brood-feeding behavior and increase egg-laying, and likewise, late-stage queens increase their brood-feeding behavior and decrease egg-laying when workers are removed from their nests. Further, brood-feeding and egg-laying behavior were negatively correlated in these queens. We used an Agilent brain EST-based microarray to explore a second hypothesis, that workers alter brain gene expression in nest-founding queens. We found evidence that brain gene expression in nest-founding queens is altered by the presence of workers, with the effect much stronger in late-stage founding queens. Additionally, expression levels of some genes were correlated with quantitative differences in brood-feeding and egg-laying behavior. This study provides new insights into how the transition from feeding brood to specialization on reproduction in bumble bee queens is regulated during the nest initiation phase of the colony cycle.
Project description:Our aim was to identify the genes that are responsible for caste differentiation in the primitively eusocial bumble bee, Bombus terrestris. To do this we extracted RNA from both queen- and worker-destined larvae. We extracted RNA from three key stages during bumble bee development (before, during, and after their caste becomes fixed), and then sent the sequencing to the Earlham Institute. They used mRNAseq to isolate the RNA from each developmental stage and caste pathway.
Project description: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 source, 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 in 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.
Project description:Our aims in this study were: 1) to identify the miRNAs of the bumble bees Bombus terrestris and B. impatiens; 2) to compare the total numbers of miRNAs between both bumble bee species and between them and the honey bee, Apis mellifera; and 3) to test whether the sequences and expression patterns of miRNAs were conserved between species. To investigate each of these aims we used miRNA-seq (deep sequencing of miRNA-enriched libraries) in B. terrestris, and bioinformatics prediction programs to identify miRNAs in both Bombus species. We identified 131 miRNAs in B. terrestris, and 114 in B. impatiens; of these, 17 were new miRNAs that had not previously been sequenced in any species. We found a striking level of difference in the miRNAs present between Bombus and A. mellifera, with 103 miRNAs in A. mellifera not being present in the genomes of the two bumble bees. miRNA profiles of Bombus terrestris at two developmental stages in larvae. This submission represents 'Bombus terrestris' component of study.