The Soay sheep on St Kilda, the free-living population which is the subject of this project, offers an unprecedented opportunity to dissect the architecture of fitness related traits. In this project, 588 animals belonging to a larger pedigree (882 animals) were genotyped to build a complete genetic map comprising 251 markers. Consequently, a whole genome scan was carried out to detect qualitative and quantitative trait loci. Different morphological and physiological traits were chosen on the basis of their relationship to fitness. The loci affecting the Mendelian polymorphisms of horn type and two aspects of coat colour were mapped with good reliability (<i>Horn type </i>mapped to chromosome 10, <i>Coat colour </i>to chromosome 2, <i>Coat pattern </i>to chromosome 13; LOD scores >3). Several quantitative traits were analyzed and one genomic region showed significant linkage with the variation in jaw length (chromosome 11, LOD = 3.59). In addition, suggestive linkages were detected for hind leg length (chromosome 15, LOD = 2.89), birth weight (chromosome 8, LOD = 2.54), and timing of birth (chromosome 2, LOD = 2.70). Finally, two suggestive linkages were scored for resistance to the gastrointestinal parasite coccidian (chromosome 3 and X, LOD = 2.68 and 2.21 respectively). This project is one of the first attempts to dissect the genetic architecture of complex traits in the wild through linkage mapping. The results reported here will improve our understanding of the evolution and genetics of natural populations by allowing a more realistic modelling of the study traits and by opening the way towards the molecular characterisation of the genomic regions of interest.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:641552 |
| Date | January 2006 |
| Creators | Beraldi, Dario |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/10789 |
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