Chicken fatness: from QTL to candidate gene

Excessive fat is a well known problem in poultry. It depresses feed efficiency, has no commercial value, and is less appreciated by consumers. Therefore, considerable research effort has been applied around the world to study factors associated with fat deposition and methods of decreasing it.his dissertation concerns the identification of genes controlling fat deposition in broilers. The strategy used to identify these genes is the so-called positional candidate gene approach. This approach moves from mapping quantitative trait loci (QTL) towards the identification of candidate genes. A total genome scan of a large three generation broiler population has resulted in the localization of QTL for fat deposition. Several of these QTL are confirmed as well as new QTL are identified in an advanced intercross line produced from this broiler population. The construction of high resolution comparative maps has helped to identify potential candidate genes for fat deposition mapped in the QTL regions. These genes and the polymorphisms within these genes will be of interest for future research. Identified SNPs can be used to refine the map position of the QTL by analysing linkage and linkage disequilibrium.Finally, a causal link between the genetic trait and the candidate genes can be established from functional evidence.