The fitness consequences of inbreeding in wild flax. (Durham)
This project aims to improve our understanding of inbreeding and its relationship with fitness, a fundamental aspect of evolution. We will use wild flax as a model to study this important relationship, thereby raising the possibility of rapidly translating results into sustainably enhancing agricultural production via genetic improvement of crops. Our research in wild flax will reveal the extent to which natural selfing leads to purging and the development of a genome more resistant to inbreeding depression. We will use new genotyping by sequencing technologies to obtain an unprecedented genome-wide perspective on inbreeding and its evolution, allowing the identification of relevant genes, and therefore the consideration of molecular mechanisms. Inbreeding is widely understood to reduce fitness through both the expression of recessive deleterious alleles in homozygotes, and through over-dominant allelic interactions. Even naturally highly inbreeding organisms cannot completely purge their genetic load by selection because of faster drift at reduced effective population size. For many crops, including flax, elite lines have been intensively inbred to optimize the stable expression of desirable traits. However, these same lines then suffer inbreeding depression as studies of flax have found up to 91 % heterotic increases in F1 seed yield following controlled crosses. However, the agronomic potential of heterosis has only been fully realized in hybrid varieties of maize so far. Only recently have genotyping technologies advanced to a stage where it is possible to test the long-held hypothesis that heterozygosity positively correlates with fitness using genome-wide data for many individuals of non-model organisms. Initial results are encouraging but more research is needed in organisms showing a wider range of mating systems and population structures to better understand the fitness consequences and genetic basis of inbreeding.
For further information see the website: https://www.dur.ac.uk/biosciences/
Please submit a full CV and covering letter directly to [email protected]
This is a 4 year BBSRC studentship under the Newcastle-Liverpool-Durham DTP. The successful applicant will receive research costs, tuition fees and stipend (£14,057 for 2015-16). The PhD will start in September 2016. Applicants should have, or be expecting to receive, a 2.1 Hons degree (or equivalent) in a relevant subject. EU candidates must have been resident in the UK for 3 years in order to receive full support. There are 2 stages to the application process.
Brennan AC, Hiscock SJ, Abbott RJ. (2014) Interspecific crossing and genetic mapping reveal intrinsic genomic incompatibility between two Senecio species that form a hybrid zone on Mount Etna, Sicily. Heredity 113: 195-204 doi:10.1038/hdy.2014.14