Year: 2024
Type: article
Abstract: In eusocial insects, the molecular basis of worker reproductivity, including how it changes with eusocial complexity, remains relatively poorly understood. To address this, we used mRNA-seq to isolate genes differentially expressed between ovary-active and ovary-inactive workers in the intermediately eusocial bumblebee Bombus terrestris. By comparisons with data from the advanced eusocial honeybee Apis mellifera, which shows reduced worker reproductivity, we characterized gene expression differences associated with change in worker reproductivity as a function of eusocial complexity. By comparisons with genes associated with queen-worker caste development in B. terrestris larvae, we tested the behavioral-morphological caste homology hypothesis, which proposes co-option of genes influencing reproductive division of labor in adults in morphological caste evolution. We conducted comparisons having isolated genes expressed in B. terrestris worker-laid eggs to remove the potential confound caused by gene expression in eggs. Gene expression differences between the B. terrestris worker phenotypes were mainly in fat body and ovary, not brain. Many genes (86%) more highly expressed in ovary of ovary-active workers were also expressed in worker-laid eggs, confirming egg-expressed genes were potentially confounding. Comparisons across B. terrestris and A. mellifera, and with B. terrestris larvae, returned significant percentage overlaps in differentially expressed genes and/or enriched Gene Ontology terms, suggesting conserved gene functions underpin worker reproductivity as it declines with increasing eusocial complexity and providing support for the behavioral-morphological caste homology hypothesis. Therefore, within bees, both a degree of conserved gene use and gene co-option appear to underlie the molecular basis of worker reproductivity and morphological caste evolution.
Source: Genome Biology and Evolution
DOI: 10.1093/gbe/evae269
Institutions: University of East Anglia, Norwich Research Park
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,992
Awards: Evolution and molecular basis of caste differentiation in bees, The genetic basis and ground plan of eusocial worker evolution, Underpinning UK Bioscience Research with high-throughput single molecule sequencing, G3476951221, G3778085983, G4978037697, G5010142495, G5804698758, G706517099, G7107165544, G7916542534, G8749716906, Social evolution and the evolution of ageing: testing the hypotheses, G8827776012, G994606719
OpenAlex ID: W4405335571