Forty-seven to 56 each of the selection lines for acute withdrawal and consumption were genotyped using a panel of 768 SNPs. Because of the genetic drift that occurs during selection, it was estimated that the threshold for a significant association was LOD> 10. Seven reciprocal QTLs were detected (Table 1). The table illustrates the marker with the peak LOD score. The founding HS4 population was genotyped to determine if the reciprocal QTLs would also be detected. All of the QTLs were detected with the appropriate haplotype structure (see Table 1), with the exception of the reciprocal QTL on Chr 6. The data in Table 2 illustrate the allele segregation for the reciprocal QTLs. For some of the QTLs, there was a complete loss of heterozygosity (see the QTLs on Chr 1, 3, and 16).
