Status of genome and QTL mapping in pigs - Data of Hohenheim F-2 families

Three informative F-2 families (by use of European Wild boar (W), Pietrain (P) and Meishan (M)), each with more than 300 animals, were genotyped for e venly spaced marker loci and recorded or more than 100 quantitative traits. Linkage and QTL mapping data for 8 chromosomes are presented (74, 76 and 7 5 mapped loci in families WxP, MxP and WxM, resp). Linkage maps gave eviden ce of heterogeneity in recombination between sexes and families. The male t o female recombination ratio were 1.!9 (WxP), 1.35 (MxP) and 1.27 (WxM). Se veral QTLs were mapped for performance traits of growth, carcass and meat q uality. These QTLs are located on different chromosomes and influenced by f amilies. Larger effects were found on chromosome 6 and 7, and e.g. up to 60 % of the phenotypic F-2 variance for meat quality traits was associated wi th chromosome 6. Candidate genes are proposed for some of the QTL intervals . The subsequent QTL mapping use a combined strategy of genome-wide marker mapping with a positional candidate gene approach in order to identify gene s which are significant for breeding.