Bumble bees are a diverse group of key pollinators that suffer from the negative impact of anthropogenic change. This results in declining and fragmented populations that impacts on the bees themselves and so on the wild flowers and crops that they pollinate .
Importantly, the genetics and life-history of bumble bees make these changes especially damaging .The aim of this PhD research is to investigate two understudied and important genetic issues important to the persistence of bumble bee populations in changing environments.
Haplodiploidy. Female bees (workers and queens) are diploid (maternal and paternal genome copies), whereas males are usually haploid (maternal copy only). An upshot is that natural selection potentially acts more effectively because genetic dominance is absent in genes expressed in males. Compared to diplo-diploids (like us), theory predicts that mildly deleterious variants – potentially important for future adaptation to changing environments – are more efficiently removed by selection, whereas adaptive but recessive variation is more likely fixed by selection.
Sex determination. Bumble bee sex is thought to be determined by a single genetic locus: the complimentary sex determination locus (CSD). Normally, heterozygotes develop as females, while hemizygotes (haploid) develop as males. However, inbreeding or reduced genetic variation caused by declining populations leads to diploid homozygotes at CSD which develop as diploid males. Diploid males have an enormous impact on population fitness as they replace valuable workers. Importantly, theory shows that diploid male production greatly increases the likelihood of population extinction .
Currently we have little empirical data on whether natural selection is more efficacious in haplodiploid species or on the level of genetic variation at the CSD locus. The aim of this PhD is to help fill this knowledge gap.
Questions to answer include:
1) Are there lower levels of potentially deleterious genetic variation:
a. in bumble bees compared to diploid insects?
b. in male expressed genes compared to female expressed genes within bumble bees?
2) What genetic variation is at CSD in bumble bees?
3) Does decreased genetic variation at CSD correlate with population extinction?
UK Bachelor Degree with at least 2:1 in a relevant subject or overseas equivalent.
Available for UK and EU applicants only.
Applicants must meet requirements for both academic qualifications and residential eligibility: http://www.nerc.ac.uk/skills/postgrad/
How to Apply:
Please follow refer to the How to Apply section at http://www2.le.ac.uk/study/research/funding/centa/how-to-apply-for-a-centa-project
and use the Genetics Apply button to submit your PhD application.
Upload your CENTA Studentship Form in the proposal section of the application form.
In the funding section of the application please indicate you wish to be considered for NERC CENTA Studentship.
Under the proposal section please provide the name of the supervisor and project title/project code you want to apply for.