Analysis of allele segregation distortion in a swine resource family

Segregation distortion of alleles was found in several regions of the genom e in allele type analyses of genetic markers for a swine resource family th at had been constructed by crossing Gottingen miniature pig and Meishan bre eds. From these regions, a region on chromosome 6 presented a distortion ov er several consecutive markers. This chromosome 6 region was subsequently f urther investigated to reveal that alleles of a chromosome 6 homologue of t he Gottingen miniature pig were not found in a homozygous family member. Th e litter size of F1-crosses which were able to produce homozygotes in this region were 24% smaller, on average, than F1-crosses which were unable to p roduce homozygotes. This indicated that this region of the chromosome 6 hom ologue contained a recessive gene or genes which could terminate fetal deve lopment. An additional 10 markers were subsequently used to investigate the region more precisely. These studies revealed that this region spans 7 cM and is located between markers Sw855 and Sw122. Since current comparative m aps show that this region corresponds to the human chromosome 19 q-arm, gen es positioned on the human chromosome 19 q-arm were screened to select 20 c andidate genes. These included the pregnancy-specific beta-1-glycoprotein g ene.