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.
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.
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: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:Our aim was to use next-generation sequencing to identify the miRNAs associated with caste determination in queen-destined and worker-destined larvae of the bumble bee, Bombus terrestris. We found that two miRNAs (miR-6001-5p and miR-6001-3p) were upregulated in queen-destined larvae that had passed the critical developmental period when caste becomes irreversible in this species. The two miRNAs form a duplex that is expressed from the gene VHDL, a homologue of Vitellogenin. This finding suggests a new connection between miRNAs and a key protein known to play multiple roles in regulating reproductive division of labour in eusocial Hymenoptera .
Project description:The common Eastern bumble bee Bombus impatiens is native to North America and is the main commercially reared pollinator in the Americas. There has been extensive research on this species related to its social biology, applied pollination, and genetics. The genome of this species was previously sequenced using short-read technology, but recent technological advances provide an opportunity for substantial improvements. This species is common in agricultural and urban environments, and heavy metal contaminants produced by industrial processes can negatively impact it. To begin to identify possible mechanisms underlying responses to these toxins, we used RNA-sequencing to examine how exposure to a cocktail of four heavy metals at field-realistic levels from industrial areas affected B. impatiens worker gene expression.
Project description:Our two main aims were 1) to isolate age-related changes in gene expression in queens of the eusocial bumble bee, Bombus terrestris; and 2) to determine whether experimentally increasing the costs of reproduction (by removing eggs) caused changes in age-related gene expression in these queens. To address these aims we extracted RNA from three key tissues (brain, fat body and ovary) from queens at two time points (10% and 60% mortality phases). Each of these queens had experienced one of two treatments: an egg removal (R) treatment (to increase the costs of reproduction) and an egg removal and replacement (C) treatment (to control for the effects of disturbance caused by egg removal).
Project description:Social organization is commonly dynamic with extreme examples in annual eusocial insects ("annual superorganisms"), but the signals and mechanisms regulating social organization remained elusive. In annual bumble bee colonies, larvae with a close contact to a queen do not differentiate into gynes, pupate at an earlier age, and are commonly smaller than siblings that do not contact a queen. We combined detailed observations, proteomics, microRNA transcriptomics, and gland removal surgery, to study the regulation of brood development and division of labor in the model bumble bee Bombus terrestris. We found that regurgitates fed to larvae by queens and workers differ in their protein and microRNA composition. The proteome of the regurgitate overlaps significantly with that of the mandibular (MG) and hypopharyngeal glands (HPG), suggesting that these exocrine glands are the sources of some regurgitate proteins. The MG and HPG proteomes , but not that of the salivary glands, differed between queens and workers, with the caste-specificity preserved for the MG and regurgitate proteomes. Queens subjected to a surgical removal of the MG showed normal behavior and brood care, but failed to manipulate the developmental program of the brood they reared. These findings suggest that substances in the queen MG are fed to larvae and influence their developmental program. As the colony grows, an increasing number of workers feed larvae and by that reduce the effects of the queen substances, such that she can no longer manipulate the development of all larvae, and the colony switches from producing workers (ergonomic phase) to gynes (reproductive phase).