Development And Application Of Molecular Markers To Assess The Activity Of The Pig Genome Of Retrotransposons

Retrotransposons are widely spread in biological genome,which have the rich polymorphism,and play an important role in the animal and plant genome evolution.As the random translocation of retrotransposons,the probability of different individuals have the same insert sites are almost impossible,and they must be by reverse transcription events,which are hereditary in parents.Therefore,retrotransposons will show insertion polymorphism in different populations biology,and which have form transcription activity potentially,or have occurred the transcription events recently.On this research,the specific amplification primer designed were according to the conservative sequences and simple repeat sequences of genome in the retrotransposons,we were detecting the transcription transposon in varieties or species exist insertion polymorphism in Landrace,Turok,Meishan,Jiang-QuHai,Tibetan and wild pigs,cloning these polymorphic loci,and sequencing and comparing,and then doing analysis and classification.We were designing side-binding specific primers related to insertional locus with sequences of each category,and cooperated with conservative-sequence primers of retrotransposons,to detect whether cloning insertion sites are polymorphic in different population,and doing within varieties correlation analysis polymorphism loci and their reproductive performance which containing retrotransposon insertion polymorphism.The results are as follows,1,Screening of primers used to insertion polymorphic locusUsing two retrotransposons specific primers(L15 'UTR,L15' UTR)and 13 microsatellite primers to amplifiy insertion sites of L1 in the genome of Landrace,Duroc,Meishan,Jiang-QuHai,Tibetan and wild pigs.The results shown that the L1 of retrotransposon presented different polymorphism distribution in seven varieties,moreover,there were two microsatellite primers(Primer CT,Primer TC)combinated to retrotransposon specific Primer amplified the stripes,which were clear,well repeatable,and varieties of polymorphism between and within population of seven varieties were also obviously.2,The distributed detection of retrotransposon insertion polymorphism loci groupAdopting two screened microsatellite primers and retrotransposon specific primers to clone insertional locus of different varieties of swine genome,and total of 33 insertional locus were cloned,and the result of sequence alignment analysis of clone sites shown that those could be divided into 20 types(named a,b,c,d,e,f,a,b,c,d,e,f,G,H,I,J,K,M,N,O respectively),and designed primers of flanking specific sequence which were resulted from the trail above,to check distribution frequency of the insertion site in the population.According to the research,there were three insertional locus in Landrace of all 20 types of insertion sites presented polymorphic,and they were E,I,and K respectively.its distribution frequency in Landrace community were 0.53,0.15 and 0.01 correspondently;Moreover,there had four class insertional locus polymorphism in Duroc were A,E,G,M,respectively,and distribution frequency were 0.51,0.89,0.03 and 0.03 in Duroc group;What's more,seven insertional locus polymorphism were found in Sujiang swine group,and they were A,E,G,H,I,K and M,respectively.And the distribution of frequency Sujiang pigs population were 0.1,0.35,0.04,0.35,0.37,0.39 and 0.03;However,the similar insertion of polymorphic loci weren't found in the Large White pigs.3,The correlation analysis of retrotransposon-insertion polymorphism distribution and reproductive performanceBy correlating the distribution of retrotransposons in different varieties and the breeding traits associated with pigs,we analysed the relationship between the distribution of all the screened specificity insertional locus distributed varies in different kinds of swine populations and reproductive traits.In Landrace,Large White,Sujiangzhu pigs it shown no significant(p>0.05),however,E loci insertion of Duroc decreased its reproductive traits on litter size and newborn litter weight(p<0.05).In summary,this study established a molecular marker screening methods based on retrotransposons L1D1,obtained 14 polymorphic markers in four varieties,provided a new molecular markers for QTL analysis and population evolution studies.