采用外周血淋巴细胞培养制备染色体标本,对13/17罗伯逊易位猪的3种杂交组合的394头后代进行核型分析.出现3种核型猪:13/17易位纯合子猪[2n=36,XY或XX,rob(13;17)],13/17易位杂合子猪[2n=37,XY或XX.rob(13;17)]和正常核型猪[2n=38,XY或XX].应用PCR-RFLP技术在POU1F1基因的1 746 bp扩增片段中检测到1个Rsa Ⅰ限制性内切酶的多态位点.应用PCR-SSCP技术检测POU1F1基因第4外显子,在3种杂交后代群中均未检测到突变.遗传多态性分析结果表明:Rsa Ⅰ酶切多态位点的突变在3种杂交后代群中A等位基因和AA基因型频率占优势,在3种核型群体中也是A等位基因和AA基因型频率占优势,其中AB基因型频率在易位杂合型群体中较高.各杂交后代群均未达到Hardy-Weinberg平衡,不同核型群亦处于非平衡状态.13/17易位杂合子猪×13/17易位杂合子猪和13/17易位杂合子猪×约克两杂交后代群的PIC表现为中度多态,而13/17易位杂合子猪×皮杜杂交后代群表现为低度多态;易位杂合型群体表现为中度多态,正常核型和易位纯合型群体表现低度多态性.

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.According to karyotype all the pigs were divided into different groups.A RsaⅠrestriction enzyme polymorphic site(locus A) in a 1746 bp fragment of porcine POU1F1 gene was detected by using PCR-RFLP analysis and a mutation(locus E) in intron 5 of porcine POU1F1 gene was found by using PCR-SSCP analysis in three hybrid populations.At the same time,the effects on growth traits and carcass traits of POU1F1 gene were estimated according to their growth and slaughter data.The result of population genetics analyses demonstrated a significant effect on growth in locus A and a significant association with growth and loin eye area for locus E(P0.05).The results indicated that growth and loin eye area were correlated with polymorphisms of POU1F1 gene which could be used as an interpretation for genetic mechanism on heterozygous advantage of Robertsonian translocation at the molecular level.

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.