PT  - JOURNAL ARTICLE
AU  - Hollie Marshall
AU  - Zoё N. Lonsdale
AU  - Eamonn B. Mallon
TI  - Methylation and Gene Expression Differences Between Reproductive Castes of Bumblebee Workers
AID  - 10.1101/517698
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 517698
4099  - http://biorxiv.org/content/early/2019/01/11/517698.short
4100  - http://biorxiv.org/content/early/2019/01/11/517698.full
AB  - Phenotypic plasticity is the production of multiple phenotypes from a single genome and is notably observed in social insects. Multiple epigenetic mechanisms have been associated with social insect plasticity, with methylation being explored to the greatest extent. Methylation is known to play a role in caste determination in Apis mellifera but there is limited knowledge on it’s role in other bee species. In this study we analysed whole genome bisulfite sequencing and RNA-seq data sets from head tissue of reproductive and sterile castes of the eusocial bumblebee Bombus terrestris. We found CpG methylation is enriched in coding regions and exons whereas non-CpG methylation is more evenly spread throughout the genome. Methylation has a positive relationship with gene expression and is found in lower levels in differentially expressed genes. We found no evidence for a role of methylation in alternative splicing. We did however find methylation differences between reproductive castes with some differentially methylated genes involved in behaviour and reproductive processes. Our results also indicate high inter-colony variation in methylation. This study provides the first insights into the nature of a bumblebee caste specific methylome as well as it’s interaction with gene expression, alternative splicing and caste determination, providing greater understanding of the role of methylation in social insect phenotypic plasticity.