| In this study,the polymorphism in PRLR,GH and IGF-1 genes of Crossbreed,Mura,Nili-ravi buffaloes and Holstein dairy cows were detected respectively by PCR-SSCP method and Sequenom MASSARRAY_iPLEX Gold assay(Sequenom)using a chip-based matrix-assisted laser desorption ionization time-of-flight(MALDI-TOF)mass spectrometer technology.Then the association with the milk production traits was analyzed by the use of General Linear Model(GLM)and least square analysis.The following results were obtained:1.The polymorphism informations were found in PRLR exons 3,5 and 10 by PCR-SSCP analysis。After sequencing and comparison,the Intra and inter species nucleotides mutations were found in PRLREXON3,in which the T-G mutation led to GG,QGT and TT genotypes.At this locus the Hardy-Weinberg equilibrium has been reached only in the crossbreed buffalo population,the X2 value was 0.132(P>0.01).At the PRLREXON5 locus the results showed that some nucleotides variation between the buffalo species populations and the Holstein dairy cows,the G-A nucleotides mutation in both species has led to the genotypes AA,AG,GG At this locus also only the in the crossbreed buffalo population that the Hardy-Weinberg equilibrium has been reached,the X2 value was 0.028(P>0.01)In the PRLREXONIO locus,the sequencing result showed that at the 9637bp,all the buffaloes species have T-C nucleotides mutation leading to the TT,TC and TT genotypes.At this locus,the crossbreed,Mura and Nili-ravi buffaloes populations are in Hardy-Weinberg equilibrium with the X2 values respectively 5.853,0.885 and 1.079(P>0.01).The analysis of the association of the three polymorphisms loci with milk production traits using the general linear model(GLM)and least square showed that only in PRLREXON10 locus that the difference in milk yield between TT and CC genotypes was significant(P<0.05).2.The SNP polymorphism in GH 5’region and IGF-1 intron 1,2,3,5 and 6 was studied by using the MASSARRAY_iPLEX Gold assay(Sequenom)using a chip-based matrix-assisted laser desorption ionization time-of-flight(MALDI-TOF)mass spectrometer technology.The results were as follow:(1)Most of the GH 5’region SNP loci are polymorphic only in Holstein cow and Crossbreed buffaloes.Polymorphism is not almost found in Mura and Nili-ravi buffaloes.In Holstein cows and crossbreed buffaloes population,are in Hardy-Weinberg equilibrium(P>0.05)at the GH 5’region polymorphic loci detected。Analysis of the correlation between the different loci genotypes and milk production traits in Holstein cows and Crossbreed buffaloes showed no significant difference.(2)The detection of IGF-1 gene introns 1,2,3,5,6 SNP in experiment cattle results showed that IGF-1i1 and IGF-1i3 are polymorphic in Crossbreed buffalo and IGF-1i1,IGF-1i5,IGF-1i6 and IGF-li3 are polymorphic in Holstein cows。The Hardy-Weinberg analysis showed that the crossbreed buffalo at the IGF-1i6 and the Holstein cows at the IGF-1i3 loci are not in equilibrium.Analysis of the correlation between the different loci genotypes and milk production traits in Holstein.:cows and Crossbreed buffaloes showed also no significant difference. |
