The Polymorphism Study On The Inhibin Beta Subunit Gene By PCR-RFLP And PCR-SSCP In Small Tail Han Sheep

In this research, the methods of PCR-RFLP to detect sheep inhibin beta-A subunit gene (INHBA) mutation and PCR-SSCP to detect sheep inhibin beta-B subunit gene(INHBB) mutation were established in four sheep populations. Analysing the INHBA gene mutation, two pairs of primers were used and the PCR product of the first primer(M1) was a specific fragment of INHBA gene exon â…¡(marked in INHBAâ… ).The length of the fragment was 402 bp. The mutation in the gene loci wasn't detected. The PCR product of the second primer(M2) was a specific fragment of INHBA gene(marked in INHBAâ…¡) and the length of the fragment was 1100 bp. No complete sequence of sheep INHBA gene was reported at present, so the second primer was designed by the complete sequence comparison between cattle INHBA gene and the sheep inhibin beta-A subunit mRNA. The PCR product included the complete sequence of INHBA gene exonâ…¡and part of the intron sequence. By Mspâ… RFLP analysis two genotypes were observed. The banding patterns of Mspâ… RFLP in 1.5% agarose gel were 641/183/163/107bp marked in AA genotype and 641/390/183/163/107bp marked in AB genotype. So, there were two alleles in these sheep populations and the gene frequency per sheep population was calculated. The gene A was predominant. The result of the Hardy-Weinberg equilibrium test indicated the gene frequency and the genotype frequency were in equilibrium. The PIC values of the INHBAâ…¡gene in four sheep populations were all less than 0.25.The analysis of variance indicated the genotype of INHBAâ…¡significantly affected the first litter size and the second litter size in Small Tail Han Sheep(P<0.05).The analysis of significance indicated that the diffence between least squares means(LSM) of the INHBAâ…¡genotypes for the first and the second litter size reached to significant level(P<0.05).For the first litter size, the average value of LSM for AB was 0.45 more than LSM for AA (P<0.05).For the second litter size, the average value of LSM for AB was 0.53 more than LSM for AA (P<0.05= Because exonâ…¡was the DNA sequence coding the mature inhibin beta-A subunit, it was sequenced and compared with the known 9 sheep breeds'sequence...