Project description:Bumblebees (Hymenoptera: Apidae) are important pollinating insects that play pivotal roles in crop production and natural ecosystem services. To achieve a comprehensive profile of accessible chromatin regions and provide clues for all possible regulatory elements in the bumblebee genome, we did ATAC-seq for Bombus terrestris samples derived from its four developmental stages: egg, larva, pupa, and adult, respectively. The sequencing reads of ATAC-seq were mapped to B. terrestris reference genome, and its accessible chromatin regions were identified and characterized using bioinformatic methods. Our study will provide important resources not only for uncovering regulatory elements in the bumblebee genome, but also for expanding our understanding of bumblebee biology.
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:Pollinators are of crucial importance for maintaining biodiversity in ecosystems and for agriculture, including the Buff-tailed bumblebee Bombus terrestris. The health decline in these populations is thought to be linked to various abiotic and biotic stressors. In the hope of protecting these populations, deciphering their immune response in stress conditions represent a critical issue. To assess this metric, we analysed the bumblebee hemolymph, as a readout of the immune status. Here, we show in laboratory conditions that bacterial infections with two entomopathogenic strains and a well-recognised inducer of defence reactions in insects, impact the systemic immune response. Analysis of the hemolymph was carried out using a two-stage approach of mass spectrometry that combines MALDI molecular mass fingerprinting (MALDI MFP or MALDI-BeeTyping®) for its effectiveness in assessing the immune status of the bumblebee through a basic “blood” test and LC-ESI-MS/MS to measure the impact of our infectious models on the “haemoproteome”. By carrying out three different types of bacterial infections, we found that the bumblebee reacts in a specific way to bacterial attacks. Indeed, bacteria impact mortality and stimulate an immune response in infected individuals that is visible through changes in the molecular composition of their hemolymph. The characterisation and label-free quantification of proteins involved in specific signalling pathways in bumblebees by LC-ESI-MS/MS revealed differences in the protein expression between the non-experimentally infected and the infected bumblebees. Our results highlights differences in the molecular composition of their hemolymph to distinguish these different infections from non-experimentally infected bumblebees, and an alteration of pathways involved in (i) immunity and defences, (ii) the metabolism of carbohydrates (glycolysis), (iii) oxidative stress and (iv) amino acid biosynthesis. To conclude, we established bioinformatics models based on molecular markers reflecting the health status of these pollinators to enable diagnosis/prognosis at the population level in response to environmental stress.