SNPs Detection And Their Association Analysis With Production Traits Of Porcine FRZB, ABCF1, IGFBP2 And BMP-3b Genes

With the development of molecular genetics and molecular biology, molecular marker-assisted selection（MAS） has been widely used in animal breeding. The SNP is currently the most widely studied and applied molecular markers. This study selects four candidate genes of the FRZB, ABCF1, IGFBP2 and BMP- 3b for SNPs detection and association analysis. The results are showed below:（1） Secreted frizzled-related protein 3（sFRP3）, encoded by the gene FRZB, is a member of the sFRP family with important roles in embryonic development. Previous studies showed that three polymorphic sites existed in this genes. In this study, we use PCR technology to verify an insertion SNP g.1541₁542 ins322（KF112870.1） at the-532 bp upstream transcription start site in its 5′-UTR.In American Large white（n=470） group, the SNP was significantly associated with back fat thickness（p<0.01）.（2） ABCF1 is a member of transmembrane transport protein family, studies have shown that A/G SNP g.8472 A〉G（NC₀10449.4） at-254 bp upstream transcription start site in 5’ flanking regulatory region was associated with birth weight. We used Msp Ⅰ-RFLP method to confirm the SNP in American Large white（n=630） group and France Large white（n=576） group. In the American Large White pigs, this SNP was significantly associated with back fat and nipple number（p<0.05）, and was also significantly associated with birth weight in France Large White pigs（p<0.05）.（3） IGFBP 2 is a member of IGFBP family, it is transported through binding to the insulin-like growth factor, and acts on the target tissue such as muscle to promote animal growth and development. We used Msp Ⅰ- RFLP method to detect the SNP g.171C〉T（GenBank Accession No. BV727778） at the third intron in Large White × Meishan F2 population（n=383）. This SNP was significantly associated with back fat thickness, loin eye height, eye muscle width, bone percentage and pH（LD）, and other traits（p<0.01）, and was significantly associated with eye muscle area, fat percentage and the ratios of fat to lean, flower fat, color value（LD） and color（BF）（p<0.05）.（4） BMP-3b regulates bone formation, and plays an important role in embryonic development. In this study, we found a SNP site g.7925 A〉G（ID₁00519926） at downstream 546 bp of the translation initiation site, and established the AlwN1- RFLP method to identify this SNP in Large White × Meishan F2 population（n=399）. This SNP was significantly associated with backfat thickness, eye muscle height, leaf fat weight and intramuscular fat（p<0.05）, and highly significantly associated with the color value（LD）, color（BF） and marble scores（LD）（p<0.01）.This research gave us a preliminary understanding of the relationship between the SNPs and pig production traits. And screening of molecular markers significantly associated with growth and meat quality traits will provide a theoretical basis for molecular marker-assisted selection for economically important traits in pigs.