Ideograms of loci that retained more than 50% heterozygosity after three generations of inbreeding across three sibling DRH families. Numbers under images indicate linkage groups. (A) Common heterozygous loci (n = 46, black lines) to all three families. Loci (n = 137) marked with red lines on chromosomes 3, 4, 5, 6, 7, 8, and 9 were homozygous and fixed for the DM allele in all three populations. The single locus in red on chromosome 12 was fixed for an RH allele. (B) Heterozygous loci unique to DRH family 16 (n = 424), (C) family 76 (n = 304), and (D) family 90 (n = 134).