Mitonuclear conflict and speciation in stickleback
Project supervisors: Dr Andrew MacColl, Dr Lisa Chakrabarti and Dr Sara Goodacre
University of Nottingham, U.K.
In eukaryotes, ‘co-adapted gene complexes’ comprised of both nuclear and mitochondrial genes must work closely together in the production of energy by oxidative phosphorylation (oxphos). When this essential biochemical cooperation breaks down, the consequences for cells and organisms are serious. Consideration of the coadaptation of nuclear and itochondrial
genes and the speed with which mitonuclear incompatibilities can evolve has stimulated a novel hypothesis for the process of speciation. This proposes that once gene flow between populations is disrupted, the high mutational rate of mitochondrial genes will lead to rapid and unpredictable divergences between populations in coadaption. The
breakdown of nuclear-mitochondrial coadaptation following subsequent secondary contact and hybridisation between divergent taxa may be a common cause of reproductive isolation and speciation. Thus far, this idea has been examined in only a handful of organisms, and only once
in vertebrates. This studentship will investigate the contribution of mitonuclear conflict to speciation in stickleback, a small fish with excellent genomic resources.
Three-spined stickleback have repeatedly colonised freshwater from the sea. The contrasting energetic and osmotic demands of marine and freshwater environments exert strong selection on genes involved in oxphos pathways, potentially favouring strong selection on nuclear-mitochondrial coadaptation. On the Scottish island of North Uist there are hybrid zones between marine and freshwater stickleback populations that
originate from distinct mitochondrial clades that are ~120,000 years diverged. Hybridisation in these contact zones is strongly asymmetric, with freshwater mtDNA introgressing into marine fish, but not vice versa. This is strongly suggestive of mitonuclear conflict contributing to speciation in these fish. In this project the student will combine traditional analysis of genetic crosses with cutting-edge genomics and
assays of mitochondrial function, as well as behavioural and ecological fieldwork, to assess the contribution of mitochondrial dysfunction to speciation in stickleback.
The project is open to students who qualify for UK Research Council funding.
This project is competitively funded through the ‘Molecules,
Cells and Organisms’ stream of the Nottingham BBSRC DTP
(http://www.nottingham.ac.uk/bbdtp/index.aspx) and applications MUST be submitted through the DTP by Monday 12th December 2016, but applicants should firstly contact Andrew MacColl (firstname.lastname@example.org) for more information (http://ecology.nottingham.ac.uk/AndrewMacColl/index.php).
Applicants should have, or expect to get, a First Class or Upper Second degree or equivalent in a relevant subject. Further experience, including a Masters degree, is likely to be advantageous. Start date: October 2017, duration 4 years.
Associate Professor of Evolutionary Ecology
School of Life Sciences
University of Nottingham
NG7 2RD, U.K.
Tel: +44 115 951 3410