moleculAr mArkers for evAluAtion of genetic diversity And in AnimAl production

INTRODuCTION Genetic markers provide information about allelic variation at a given locus. The increasing availability of molecular markers in farm animals allows the detailed analyses and evaluation of genetic diversity and furthermore the detection of genes influencing economically important traits. The majority of molecular markers used nowadays with high-throughput systems are microsatellite markers (simple tandem repeat, STR). Variable number of tandem repeats (VNTRs), random amplified polymorphic DNA (RAPD) markers, single strand conformation polymorphisms (SSCPs), restriction fragment length polymorphisms (RFLPs) and amplified fragment length polymorphisms (AFLPs) markers are not commonly applied in farm animals. Additionally within diversity and phylogeny studies specific mtDNA and Y chromosome markers are used for the identification of maternal and paternal lineages. Beyond diversity studies molecular markers are also used for mapping quantitative trait loci (QTL) and within marker assisted selection (MAS). Until recently microsatellites were the markers used for mapping quantitative trait loci for production and functional traits in farm animals (Hiendleder et al., 2003; Kühn et al., 2003) and tightly linked markers are used for marker assisted selection in practise. They are also the prerequisite for the identification of positional and functional candidate genes responsible for quantitative traits. The detailed use of molecular markers for the evaluation of genetic diversity and identification of economically important traits in animal production is presented on the basis of different examples.