Details of Award
NERC Reference : NE/L00948X/1
Genetic basis of pathogen resistance in farm and wild fish populations under inbreeding
Training Grant Award
- Lead Supervisor:
- Professor S Consuegra del Olmo, Swansea University, College of Science
- Grant held at:
- Swansea University, College of Science
- Science Area:
- Freshwater
- Marine
- Overall Classification:
- Freshwater
- ENRIs:
- Biodiversity
- Natural Resource Management
- Science Topics:
- None
- Abstract:
- Pathogens are powerful selective agents implicated in maintaining genetic variation in host resistance, a good example being the major histocompatibility complex (MHC) of vertebrates. MHC genes are key for the immune response, and their patterns of extreme polymorphism provide some of the clearest evidence of balancing selection mediated by infectious agents. However, inbred populations that persist despite low immunogenetic diversity challenge the traditional idea that bottlenecked populations should have reduced ability to respond to pathogens threatening their long-term viability. Recent declines in world fisheries have resulted in a rapid growth of the aquaculture industry. Salmonid aquaculture production has grown >ten-fold over the last 20 years but diseases in farmed salmonids have become a major economic concern due to the great losses caused by infections and the threat they pose to natural populations. Viruses and other parasites are particularly difficult to eradicate and selective breeding of resistant lines and enhancement of the immune response seem the best strategies for fighting them. However, selective breeding often causes stress, poor growth, increased vulnerability to diseases and ultimately reduced fitness. Farmed fish which originate from a reduced number of breeders, under strong selection are comparable to wild bottlenecked fish populations. We recently showed that immune-related (MHC) genetic diversity could be more critical than genome-wide diversity for parasite resistance in inbred fish populations such as these. This studentship will investigate the relative role of immunogenetic versus genome-wide diversity in pathogen resistance in wild and farmed inbred/bottlenecked fish populations. We will focus on MHC genes and use two model species: Atlantic salmon (Salmo salar) and the mangrove killifish (Kryptolebias marmoratus). Atlantic salmon is the main salmonid cultured in the world and its MHC has been widely studied. Salmon express single unlinked MHC genes and balancing selection maintains their high levels diversity. Associations between MHC genes and resistance/susceptibility to major salmonid diseases have been found in farmed populations. In addition, salmon offspring of MHC dissimilar parents display higher resistance to parasites. The mangrove killifish is a naturally inbred species. Its populations are mostly composed by self-fertilising hermaphrodites with extremely low genetic diversity but the offspring of crosses with males have higher MHC diversity and carry lower parasite loads that their inbred counterparts. The student will analyse infection outbreaks in a farm setting in collaboration with the CASE partner (Infectious Pancreatic Necrosis-IPN in A. salmon) and experimental infections at the aquarium facility at Cardiff University (Saprolegnia in killifish) comparing resistance of families with different degrees of genome-wide genetic diversity (measured as SNPs) and MHC class I and II diversity. The project will take advantage of the wide knowledge of the A. salmon genome (including a recently developed SNP chip and QTLs identified for IPN) and of the NGS techniques developed by the main supervisor for MHC genotyping. It will provide the student a unique combination of training in the industrial environment (aquaculture and veterinary), molecular and experimental laboratory analyses at Aberystwyth and Cardiff Universities and field experience in Belize to collect killifish with different levels of genetic diversity.
- NERC Reference:
- NE/L00948X/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Industrial CASE
This training grant award has a total value of £83,515
FDAB - Financial Details (Award breakdown by headings)
| Total - Fees | Total - RTSG | Total - Student Stipend |
|---|---|---|
| £16,226 | £11,000 | £56,292 |
If you need further help, please read the user guide.