ABSTRACT
With the advent of recombinant DNA, it is now possible to identify the genes that underly the genetic variation of production traits observed in livestock species. Identifying these genes is expected to allow for more efficient marker aided breeding programs and to yield novel insights in to the physiology of the corresponding traits. The most popular approach consists in an initial genetic localisation of the corresponding genes using linkage strategies, followed by positional cloning of the corresponding genes based on their known map location. In this chapter, the general principles of linkage analysis are reviewed with special emphasis on linkage analysis for quantitative trait loci (QTL). Developments in marker technology that have allowed for the generation of whole genome marker maps in livestock species in recent years are discussed, as well as new areas of research aiming at more efficient genotyping methods. Alternative mapping strategies such as bulk segregant analysis, representational difference analysis, identity-by-descent mapping and genome mismatch scanning are briefly described with their specific applications. Finally, we provide an overview of recent mapping experiments in which the described methods have been applied succesfully to livestock production traits.
