Projects per year
Abstract
The queen-worker caste system of eusocial insects represents a prime example of developmental polyphenism (environmentally-induced phenotypic polymorphism) and is intrinsic to the evolution of advanced eusociality. However, the comparative molecular basis of larval caste determination and subsequent differentiation in the eusocial Hymenoptera remains poorly known. To address this issue within bees, we profiled caste-associated gene expression in female larvae of the intermediately eusocial bumblebee Bombus terrestris. In B. terrestris, female larvae experience a queen-dependent period during which their caste fate as adults is determined followed by a nutrition-sensitive period also potentially affecting caste fate but for which the evidence is weaker. We used mRNA-seq and qRT-PCR validation to isolate genes differentially expressed between each caste pathway in larvae at developmental stages before and after each of these periods. We show that differences in gene expression between caste pathways are small in totipotent larvae, then peak after the queen-dependent period. Relatively few novel (i.e. taxonomically-restricted) genes were differentially expressed between castes, though novel genes were significantly enriched in late-instar larvae in the worker pathway. We compared sets of caste-associated genes in B. terrestris with those reported from the advanced eusocial honeybee, Apis mellifera, and found significant but relatively low levels of overlap of gene lists between the two species. These results suggest both the existence of low numbers of shared toolkit genes and substantial divergence in caste-associated genes between Bombus and the advanced eusocial Apis since their last common eusocial ancestor.
Original language | English |
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Pages (from-to) | 718-735 |
Number of pages | 18 |
Journal | Molecular Ecology |
Volume | 30 |
Issue number | 3 |
Early online date | 25 Nov 2020 |
DOIs | |
Publication status | Published - Feb 2021 |
Keywords
- Bombus terrestris
- caste determination
- caste-associated gene expression
- eusociality
- larval development
- mRNA-seq
Profiles
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Andrew Bourke
- School of Biological Sciences - Emeritus Professor
- Centre for Ecology, Evolution and Conservation - Member
Person: Honorary, Research Centre Member
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Tamas Dalmay
- School of Biological Sciences - Professor of RNA Biology
- Plant Sciences - Member
Person: Research Group Member, Academic, Teaching & Research
Projects
- 3 Finished
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Social evolution and the evolution of ageing: testing the hypotheses
Bourke, A., Chapman, T. & Huggins, T.
Natural Environment Research Council
16/10/17 → 11/01/21
Project: Research
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Evolution and molecular basis of caste differentiation in bees
Bourke, A., Collins, D. & Dalmay, T.
Biotechnology and Biological Sciences Research Council
1/09/14 → 31/08/17
Project: Research
-
The genetic basis and ground plan of eusocial worker evolution
Bourke, A., Dalmay, T. & Evans-Gowing, R.
Natural Environment Research Council
1/06/14 → 31/08/17
Project: Research