| Prolactin(PRL),Growth Hormone(GH) and Thyriod-Stimulating Hormone(TSH),secreting by animals' anterior pituitary, are essential hormones in physiology. Pituitary-Specific Transcription Factor(Pit-l) is one of the important transcription factors of GH, PRL and TSH gene. Pit-1 plays an important role in animals' growth, development and reproduction via regulating the expression of these genes.The purpose of this study is to detect the genetic variations of the pit-1 gene. Seven Chinese local pig breeds, including Beijing Black pig, Yimeng Black pig, Laiwu pig, Bama Small pig, Diannan Small-ear pig, Wuzhishan pig, Xiang pig, and four foreign breeds, which are Large White(England), Landrace, Large White(France) and Duroc were used as experimental examples. PCR-SSCP and PCR-RFLP analyses were used to analyze genetic variations in Pit-1 gene. At the same time, intron3 of pig Pit-1 gene had been cloned successfully. The results were as follows:1. Specific primer PI was designed to amplify fragment in exon4 of pig Pit-1 gene. Then one PCR-SSCP locus was discovered, it had two alleles, designated as A and B. Sequence analysis revealed that PI locus was generated because of C-T transilation, but they both code Histidine. The distribution of corresponding genotypes and alleles at this PCR-SSCP locus was analyzed in seven Chinese local breeds. A chi-square analysis suggested that Beijing Black pig and Bama Small pig reached Hardy-Weinberg equilibrium(P>0.05), the other five Chinese local breeds were in disequilibrium(P<0.05). Laiwu pig and Wuzhishan pig had low polymorphism(PIC<0.25), Beijing Black pig, Yimeng Black pig, Bama Small pig, Diannan Small-ear pig and Xiang pig had intermediate polymorphism(0.250.05), Landrace and Large White(France)were in disequilibrium(P<0.05). All of these four foreign breeds had intermediate polymorphism(0.25 |
PDF Full Text Request