The Cloning And Polymorphism Analysis Of Sheep Myogenin Gene

MyoG gene affecting performance of producing meat of sheep has been researched.Using the sequence information of other species in the GenBank,though megalign,analysed and method of PCR-SSCP,we magnified cloning and the sequence analysis and PCR-SSCP polymorphism analysis of the sheep MyoG gene that didn't report yet.The method was:first,searching for the MyoG mRNA sequence of sheep,the MyoG gene sequence of pig,human and mouse in the GenBank,we analysed the homology of the MyoG gene sequence by using DNAStar.According to the homology of the longer exon sequence we designed the primer.We used the classic method to extract the genomic DNA from the sheep blood,adopted PCR technique to magnify three parts of sequence of the sheep MyoG with them as template,and reorganized these fragment to the PMD18-T vector,slided it by two different enzymes and PCR identification,we acquired a part sequence of the sheep MyoG for 1884bps.Second,we designsd the two primers of the PCR-SSCP through MyoG exon sequence, similarly, adopted PCR technique to magnify two parts of sequence of the sheep MyoG with them as template,and by PCR-SSCP analysis of these sequence of MyoG gene in different breeds of sheep.The results were as follows:①Introns of sheep myogenin(MyoG)gene were firstly cloned and sequenced.The intronⅠlength was 766bps and the intronⅡlength was 587bps.②The analysis of nucleotide compositon showed that G/C content(58.6%)is abundant in sheep MyoG gene,and the contents(65.4%)of exons were significant higher than introns.On the basis of comparing the exons of sequence to cattle,pig,human and mouse,the finding homology were 99.2%,91.3%,89.4%和87.5% respectively.At the same time,we analysed other features of the nucleic acid sequence, aiming to provide basic data for sheep MyoG gene of structure, controlling and mechanism that sheep's growth process were studied.③The polymorphisms of PCR-SSCP existed only in the first exon,but not in the second exons.This polymorphism of the first exon was controlled by two alleles:A and B.The mutation of TC at 305bp converted allele A into B.This sequence has been registed in the GenBank,and the accession number is DQ453548.