Polymorphism Of ESR, PRLR And FSH - β Genes In Three Pigs And Their Correlation With Reproductive Traits

Studies have shown that ESR, PRLR, and FSH-β are candidate genes regulating porcinereproductive traits. Based on the three candidate genes, this study carries a marker-assistedbreeding of sows in high reproductive performance, so as to improve breeding performance.Duroc, Landrace and Yorkshire, one hundred each, selected as the subject, the study detectspolymorphism in part of gene intron and exon of ESR, PRLR and FSH-β, and uses PCR-RFLP togenotype the detected polymorphism mutations. Meanwhile, the reproductive performance indexis established. Form the best polygenic combination of distinct polymorphic sites of these threegenes under the same breed with reproduction performance index, then analyze the relationbetween the reproductive index and different genotypes, finally use the results of correlationanalysis on genotypes and reproductive traits to provide a molecular marker for optimalreproductive performance of artificially selected three breeds. The main findings of this study areas follows:1. Three polymorphic sites are detected in these three genes, namely, A＞G mutation in No.64at the site of the third region of ESR gene intron; C＞T mutation in NO.215at the site of thetenth region of PRLR gene extron, this mutation causing the corresponding amino acid in proteinto change from alanine→valine（A→V）, the two amino acids are non-polar amino acids, whichdo not change the polarity of amino acid; T＞C mutation in No.79at the site of the first region ofFSH-β gene intro. Three sites show three different genotypes and in Hardy-Weinbergequilibrium.2. In Duroc, the amplified fragments in ESR gene intron3, PRLR gene intron10and FSH-βgene intron1are polymorphic, of which CC genotype and CD genotype in PRLR showsignificant difference in Duroc breeding index contrasted with DD(p<0.05). The genotypes ofESR and FSH-β have little effect on the reproductive index (P>0.05). The genetic effect analysisof combinative genotype shows that the reproduction index of the combined genotype AACCEEdiffers from BBDDFF by3.97, showing significant difference (p<0.05). AACCEE is the bestcombinative genotype of the three genes for Duroc.3.In Landrace, the amplified fragments in ESR gene intron3, PRLR gene intron10andFSH-β gene intron1are polymorphic, of which only AA genotype in ESR show significant difference in reproductive index contrasted with AB genotype, BB genotype(p<0.05).And CDgenotype in PRLR show significant difference in reproductive index contrasted with CC and DDgenotype (P<0.05). The FF genotypes of FSH-β have effect on the reproductive index contrastedwith EE and EF genotype (P<0.05). The genetic effect analysis of combinative genotype showsthat the reproduction index of the combined genotype AACDFF differ from ABCDFF andBBDDFF by3.34and3.16respectively, showing significant difference (p<0.05). AACDFF isthe best combinative genotype of the three genes for Landrace.4.In Yorkshire, the amplified fragments in ESR gene intron3, PRLR gene intron10andFSH-β gene intron1are polymorphic. But the genotypes of three genes have no obviousdifference no obvious difference in the reproductive index (P>0.05). The genetic effect analysisof combinative genotype shows that the reproduction index of each combined genotype showsno significant difference (p>0.05).These results suggest that of the relations between ESR, PRLR, FSH-β and reproductiveperformance index, the effects of combinative genotype are not the same. And the combinedgenotypes of ESR, PRLR, and FSH-β have significant reproductive effects on Duroc andLandrace reproduction, which can be used as molecular markers to gene polymorphismmarker-assisted selection, so as to improve the reproductive performance of pigs and achievehigh economic benefit.