Variation Of IGF1,SSTR1,GSKIP,CAPN4 And FTO Genes Associated With Ovine Growth And Carcass Traits

The traits were analyzed in the study on New Zealand Romney sheep.PCR-SSCP was used to detect SNPs in the five candidate genes,named IGF1,SSTR1,GSKIP,CAPN4 and FTO.The variation of these genes associated with ovine growth and carcass traits were further analyzed to screen molecular markers for molecular breeding.The main results include:(1)Three variant sequences and two SNPs were detected in the 3′ UTR region of the SSTR1 gene.Two variant sequences and two SNPs were detected in the IGF1 promoter region.Two variant sequences were detected in the exon 2 region of the IGF1 gene.Two variant sequences and two SNPs were detected in the exon 3 region of the IGF1 gene.Two variant sequences and one SNPs were detected in the exon 1 region of the GSKIP gene,in which SNP c.*37 A>G would cause the amino acid variation of p.Met13 Val.No nucleotide variant was detected in exon 2 region of GSKIP gene.Two variant sequences and one SNPs were detected in exon 4-5 region of CAPN4 gene.Two variant sequences and one SNPs were detected in exon 6-7 region of CAPN4 gene.Two variant sequences and two SNPs were detected in the exon 8 region of FTO gene,among which SNP c.*1331 C > A would result in amino acid variation of p.Thr444 Asn.(2)Allele C of the 3′ UTR region of the SSTR1 gene was correlated with the birth weight(P = 0.023)and V-GR(P = 0.018).The birth weight of lambs without allele C had low birth weight and V-GR.Allele A was correlated with the hot carcass weight(P = 0.033),and the lambs without allele A had high hot carcass weight.(3)There was a correlation between allele A of IGF1 gene exon 2 and pre-weaning growth rate(P = 0.015),V-GR(P = 0.007),shoulder lean mass(P = 0.002),shoulder lean ratio(P = 0.004),the proportion of lean meat on the hind legs(P = 0.003)and the lambs without the allele A these traits would be low(except for the ratio of lean meat on the hind legs).Genotyping was associated with V-GR(P = 0.023),shoulder lean mass(P = 0.006),shoulder lean ratio(P = 0.014),and hind leg lean ratio(P = 0.011),and had an effect trend on the pre-weaning growth rate(P = 0.092).(4)There was a correlation between allele B of IGF1 gene exon 3 and birth weight(P = 0.014),weaning weight(P = 0.019),shoulder lean mass(P = 0.014),lumbar lean mass(P = 0.014),hind leg mass(P = 0.013)and total lean mass(P = 0.002).Sheeps without allele B had a higher birth weight and weaned weight,while shoulder lean mass,lumbar lean mass,the amount of lean meat on the hind legs and the total amount of lean meat are low.Genotype had correlation with birth weight(P = 0.031),weaning weight(P = 0.052),shoulder lean mass(P = 0.008),lumbar lean mass(P = 0.010),hind leg lean mass(P = 0.036)and total lean mass(P = 0.003).(5)There was a correlation between allele B of GSKIP gene exon 1 and birth weight(P = 0.005),hot carcass weight(P = 0.008),V-GR(P = 0.005),shoulder lean mass(P = 0.045),the proportion of lean meat(P = 0.006)and the proportion of lean meat on the hind leg(P = 0.047).Sheep without allele B had high birth weight and the lean meat of the hind leg,but the V-GR and shoulder lean mass were low.(6)The genotype of CANP4 gene exon 4-5 region was significantly associated with birth weight(P = 0.001).(7)There was a correlation between allele B of FTO gene exon 8 allele B and the proportion of lean meat in the hind leg(P = 0.048),and the proportion of lean meat in the hind legs of the sheep without allele B was low.The genotype had an effect trend on the proportion of lean meat on the hind legs(P = 0.127).In summary,the SSTR1,IGF1,GSKIP,CAPN4,and FTO gene variation were associated with partial growth and carcass traits in NZ Romney sheep and can be exploited as molecular markers for meat value traits in meat sheep.