Study On Molecular Markers Of Growth And Development In Cattle By Candidate Genes

Three cattle breeds, including Nanyang cattle, Luxi cattle, and Chinese simmental,were used as experimental population. The genetic variations of GH, GHR, IGF-I,IGF-IBP3 genes in three breeds were researched by PCR-SSCP and PCR-RFLP methodThe performance traits including the regulation of beef cattle linear valuation and bodymeasurements were measured. The association between genetic markers and performancetraits were analyzed by using general linear model (GLM). The results were as follows:1. Relativity of PCR-SSCP polymorphisms of the 3rd, 4th intron, the 5th exon, and 5'flanking region and the polymorphic HaeIII site in the 3'flanking region of the bovinegrowth hormone (GH) with growth and development traits.(1) The polymorphic PCR-SSCP sites in the 3rd, 4th intron, the 5th exon, and 5'flankingregion and the polymorphic HaeIII site in the 3'flanking region of the bovine growthhormone (GH) were examined in three breeds. The polymorphisms of the 3rd intron werecaused by C→T transition at 1547bp position. The polymorphisms of the 4th differencedfrom different breed, which T→C transition at 1978bp position in Chinese Simmental, andT→G transition at 1947bp position in Nanyang, Luxi cattle. The polymorphisms of the 5thwere caused by C→G transition at 2141bp position. And the polymorphisms of 3',5'flanking region were caused by GCC→GGC transition at 2639bp position and C→T at303bp,respectively.(2) Five polymorphic loci, GH-P1, GH-P2, GH-P3, GH-P4, GH-P5 were associated to thebovine growth and development traits. The result showed that the B allele, especiallyheterozygosity AB, at GH-P3 and GH-P4 loci had a positive relation with body weight,withers height, body length, heart girth, and beef productionindex(P<0.05)摘 要 v2. The polymorphisms of PCR-SSCP and PCR-RLFP were not inspected in the 8th, 9th,3rd, and the 5'flanking region of the bovine growth hormone receptor (GHR).3. The polymorphisms of PCR-SSCP of the 2nd, 5th exon, 5th intron and the 5'flankingregion of the bovine insulin-like growth hormone factor (IGF-I), and effects ongrowthand development traits.(1) Firstly, the polymorphism of PCR-SSCP was found in the 2nd exon of the bovineinsulin-like growth hormone factor (IGF-I), which caused by A→G at 3620bp, C→Ttransition at 3628bp and A→G transition at 3842bp. In Nanyang, Luxi, Chinese Simmentalpopulations, B allele was dominant allele, and this locus was at Hardy-weinbergequilibration.(2) The polymorphisms of PCR-SSCP and PCR-RFLP were not observed in the 5'flankingregion, 5th exon, and 5th intron of bovine insulin-like growth hormone factor (IGF-I).(3) The polymorphisms of IGF-I-P2 were associated to the bovine growth anddevelopment traits. The result showed that body weighty and heart girth with genotype AAwere higher than those of calves with genotype AB, BB (P<0.05).4. The relationship of PCR-SSCP of the 2nd, 3rd exon of the bovine insulin-like growthhormone factorbinding protein 3 (IGF-IBP3) withgrowth and development traits.(1) Firstly, the polymorphism of PCR-SSCP was found in the 2nd exon of the bovineinsulin-like growth hormone factor binding protein-3 (IGF-IBP3), which caused by T→Ctransition at 8069bp. In Nanyang, Luxi, Chinese Simmental populations, A allele wasdominant allele, and this locus was at Hardy-weinberg equilibration.(2) The polymorphisms of PCR-SSCP and PCR-RFLP were not detected in the 3rdexon ofIGF-IBP3.(3) In Luxi population, evaluation of head with genotype AA at IGF-IBP3-P5 locus waslower thanthose with genotype AB, BB.5.Analysis oncombination of GH-P3 and GH-P4, IGF-I-P2 and IGF-IBP3-P5 effects(1) The analysis of combination of GH-P3 and GH-P4 with growth and development traitsshowed that there was interaction between GH-P3 and GH-P4 locus. The effect ofcombination5 (Ａ３Ｂ３Ｂ４Ｂ４) had significant positive relation with body weight, withers height,body length, heart girth, and Index product, and was higher than ef...