Polymorphic Characteristics Of GH, GHR And FSHR Genes And Their Relations With Production Traits In BMY Cows

The growth and development traits and reproductive performance of BMY cows were investigated and measured and the polymorphisms of growth and development related genes, GH,GHR and FSHR genes, were detected. The correlationship was analyzed between polymorphisms of target genes and traits, with the purpose of providing reference for selection of BMY cows of better performance.1. The growth and development traits were traced and measured in64BMY cows from Langmu mountain beef cattle center, Yunnan. The similated function computed by Excel2003based on these measurement was:y=72.742x0.4503, with the determination coefficient of0.9788. the growth rate before12months old was increasing rapid while slower later in BMY cows.2. the mean first mate age was14months old, the first calving occurred at728days old in average, and the second pregnancy happened around1200. the time interval between two calvings was around471days, showing an early maturity, but with a long generation interval.3. Using PCR-SSCP technique, the polymorphisms of GH,GHR and FSHR genes were explored in BMY cows (n=106) from Animal Breeding Farm of Yunnan Province. The results showed: Three SNPs, site-445(G/A), site-147(C/T) at5’-flanking region and site1643(A/C) at exon5in GH gene were detected. Two SNPs of T702C, A730G were detected at exon10of GHR gene. There were three SNPs of-606(C/G),-320(T/A), and-290(G/A)at5’-flanking region and five SNPs of459(C/T),625(C/T),886(C/T),934(C/T),1116(C/G) at exon10in FSHR gene, leading to two changes of amino acids:from threonine to isoleucine (C459T) and threonine to serine (C1116G). SNP A1643C of GH gene, SNP T702C and A730G of GHR gene, SNP-606(C/G),-290(G/A) and1116(C/G) of FSHR gene, were medium polymorphic in BMY cows. They were all in hardy-weinberg equilibrium, except A730G of GHR gene.4. The individuals with AA genotype based on site-445in GH gene had significantly higher bone circumference at six month age, body weight at12month age, body weight and heart girth at24month age, and body length and BMI at36month age than those with AG and GG genotypes (P<0.05). The body length of AA was significantly higher than GG genetype at12month age(P<0.05).The heart girth of AG genetype was significantly higher than GG at6month age (P<0.05).The findings demonstrated that allele A was a beneficial mutation, good for body weight and some measurement. The SNP-147(C/T) of GH gene did not correlate significantly with growth and development traits in BMY cows. The individuals with AA genotype at site1643in GH gene had significantly higher body height at36month age (P<0.05)Birth weight and weaning weight of the individuals with genotype AA at730(A/G) of GHR gene were significantly lower than those of the genotype GG (P<0.05), and there was no statistical significance in three genotypes with the other traits. It suggested that GHR gene may be a candidate gene responsible for birth weight and weaning weight trait in BMY cows.5. The individuals with genotype CC at site-606of FSHR gene had the first calf significantly later than GG genotype (P<0.05), and delayed nearly one month, but they had the similar fisrt mating age. The genotype CT at site625of FSHR gene had the first mating age later than CC, and genotype CC at site1116first mated significantly later than GG genotype (P<0.05), suggesting that polymorphism of FSHR gene had some effect on the reproductive performance.