Study On Effects Of PRL And PRLR About Prolificacy In Sows

PCR-RFLP method was adopted to examine me variety of genes PRL and PRLR in five populations (landrace and Large White from Zhenghong; Landrace, Large White Duroc from me farm in the agriculture institute of Yiyang).Frequncies of the genes and genotypes were calculated according to the experimental results. Gathering the litter size data of examined pigs (including the total number of bom and the number of born alive), the effects of them on prolificacy were analyzedThe effects of single gene and their combined genotypes were consideredThe main results are as follows:1. The frequencies of the allele A B and C in gene PRL are different in different variety. The frequencies of genotypes PRL are different. Among alien variety tested ,the frequency of allele A and B is lower than allele C. The frequency of CC is higher man the other genotypes.2.In breeds tested ,the frequency of allele A and the frequency of genotype AA in PRLR is relatively low. The frequency of allele A is lower man allele B, the frequency of genotype AA is lower than the frequency of genotype BB.3. PRL is a candidate gene which controls the trait prolificacy in pigs.In this research the effects of PRL on prolificacy is proved to be not obvious.4. The effects of every genotype in PRLR is successively AA,AB,BB from high to low.For example,in this research, mean TNBs of genotype AA,AB,BB for PRLR in Large White are successively 12.21, 10.59, 9.80, and mean NBAs are successively 10.93, 9.34,8.16; in landrace the similar conclusion is obtained,too.It is one candidate gene controls the prolificacy in swine and its advantageous allele is allele A.5. The effects of combined genotypes of PRL and PRLR have no obvious law.Its genetic effects on prolificacy are not simply the multiplications of every genotype.6. Age is one important factor influencing of prolificacy,the TNB of first parity is less than the still parity,so does in NBA.7. The trait prolificacy is low in heritability and is sex-limitedThe progress achieved by normal selection methods is not obvious.In this research .the effects of PRLR on prolificacy is proved to be obvious,and polymorphism.so we can use it as molecular marker in MAS to improve the level of prolificacy. But the effects of PRL on prolificacy is proved to be not obvious. If the PRL can use as molecular marker in MAS, it should be study further more.