Study On The Correlation Of Genetic Polymorphism For BMP15,GDF9 And FSHβ With The Litter Size Of Pigs

The PCR technique and the PCR-SSCP technique were applied to detect the polymorphism of BMP15, FSHβand GDF9 in five breeds including Liaoning pigs, Landrace, Large White, Danyu and Duroc; then analyse the correlation between litter size and the polymorphism. Designing primers with pig gene sequence which have been published in GenBank, PCR amplification and Sequencing analyzed the gene; while the correlation between litter size and the polymorphism of the Alu was analyzed by means of Bioinformatics and GLM. The results showed:2 primers(primer1 and primer2) were designed to detecte the mutations in BMP15, and found the mutations including 5582C/T(TCC-TCT), 6031 T/C(AAT-AAC)and 6056C/T (AAC-AAT).6031 T/C (AAT-AAC)was a samesense mutation. In 6031 T/C site C allele was dominant in all five breeds except Liaoning pigs which T was dominant.5 primers(primer3, primer4, primer5, primer6 and primer7) were designed to detecte the mutations in GDF9. Sequence of primer 3 detected an around 300 bp InDel polymorphism. Sequence of primer 4 detected 2 heterozygous mutations: 3422C/T and 3427 C/T. Liaoning Pigs are heterozygous in 3422C/T and 3427 C/T, while others were C and T respectively, and two allelomorphic genes close to each other. Sequence of primer 5 detected 2 heterozygous mutations. Liaoning Pigs are heterozygous while others were homozygous gene, and two allelomorphic genes close to each other. Sequence of primer 6 detected 6 polymorphism including a 3 bp Del sequence. Sequence of primer 7 was a part of sequence of primer 6, and the sequence of primer 7 designed was to detect the difference among different breeds by PCR-SSCP. The results showed: litter size had no distinct difference in different breeds, parities and genetypes (P>0.05).1 primer (primer8) was designed to detecte the mutations in FSHβ, and found the InDel polymorphism. The results showed: litter size had a high distinct difference in different breeds, parities and genetypes; Litter size of Dominance genotype BB was 1.3 more than that of AA (p<0.01).The Alu InDel polymorphism: The PCR(Polymerase chain reaction, PCR) technique was applied to amplificate the the Alu sequence of FSHβand GDF9 in five breeds including Liaoning pigs, Landrace, Large White, Danyu and Duroc; then the correlation between litter size and the polymorphism of the Alu were analyzed by means of Bioinformatics and GLM. The result showed that the genes of FSHβand GDF9 associated to affect the litter size of sows, which could be seen as the genetic marker. It is the first time to certify that they linked with the major gene of litter size in four breeds including Liaoning pigs, Landrace, Large White, Danyu and Duroc. Litter size of Dominance genotype BBDD was 1.5 more than that of AACC (p<0.01), and the predominance genotype of FSHβand GDF9 would be utilized as DNA marker for improvement of reproduction trait in practice of pig breeding.