Karyotype analysis was carried out by means of culturing whole peripheral blood from 394 pigs, which were produced from three hybridization combinations of 13/17 Robertsonian translocation pig. Three types of karyotype were detected in these hybrids, i.e., the homozygous pigs [2n=36, XY or XX, rob (13; 17)], the heterozygous pigs [2n=37, XY or XX, rob (13; 17)], and the normal karyotype pigs [2n=38, XY or XX]. A Rsa restriction enzyme polymorphic site in a 1 746 bp fragment of porcine POU1F1 gene was detected by PCR-RFLP analysis. While no mutation in exon 4 of porcine POU1F1 gene was detected by PCR-SSCP analysis in the hybrids of the three hybridization combinations. Population genetics analysis showed that for Rsa-RFLP, the frequencies of allele A and genotype AA were significantly higher than allele B and genotype BB in the three hybrid populations and the three type of karyotype populations. The frequency of genotype AB was higher in the heterozygous translocation population than in the other two karyotype populations. Chi-square test suggested that all the populations did not reach Hardy-Weinberg equilibrium. The progeny populations of heterozygous 13/17 translocation pig x heterozygous 13/17 translocation pig, heterozygous 13/17 translocation pig x Yorkshire, and heterozygous pig population had medium polymorphism and others had low polymorphism.
