The Expression Regulation Of IGF1 Gene And Its Association With Porcine Growth Traits

Insulin-like growth factor 1?IGF1?,also known as Somatomedin C,is a member of the Insulin-like growth factor?IGFs?system.IGF1 plays an important role in the growth of animals.It can mediate growth hormone to promote growth and regulate the proliferation and differentiation of mammalian ovarian granulosa cells.In the previous study,our research group found polymorphisms in the Poly T site and?CA?_n microsatellite locus in the promoter region of the IGF1 gene,and the Poly T site affected the transcriptional activity of the IGF1 gene.Based on this study,Using Landrace as the research object,the poly T sites and?CA?_n microsatellite loci were genotyped by SSR fluorescence labeling technology,and the association with the growth trait data of Landrace was performed.Finally analyze the effects of four microsatellite haplotypes?CA?₁₇-11T,?CA?₁₈-11T,?CA?₁₉-11T and?CA?₂₀-11T on IGF1 gene transcription activity.The specific findings are as follows:?1?The presence of alleles 10T,11T and 12T in the promoter region of porcine IGF1 gene was detected by SSR fluorescent markers.The frequency of the 11T allele was the highest,0.89;four genotypes were found:10T/11T,11T/11T,11T/12T and12T/12T,respectively.Of which 11T/11T genotype had the highest frequency,0.8;the PolyT of IGF1 gene promoter was in Hardy-Weinberg equilibrium?p<0.05?.The correlation analysis with growth traits of landrace showed that the genotype 11T/11T showed a tendency of being superior to 11T/12T in growth traits data such as body length,age up to 115 kg body weight and eye muscle area.?2?Through SSR fluorescent markers,the?CA?_n microsatellite locus in the promoter region of IGF1 gene was found to have four alleles:17CA,18CA,19CA,and 20CA;and the frequency of?CA?₁₈8 and?CA?₁₉9 alleles was higher than others:0.44 and 0.38,respectively;ten genotypes were found:?CA?₁₇/?CA?₁₇,?CA?₁₇/?CA?₁₈,?CA?₁₇/?CA?₁₉,?CA?₁₇/?CA?₂₀,?CA?₁₈/?CA?₁₈,?CA?₁₈/?CA?₁₉,?CA?₁₈/?CA?₂₀,?CA?₁₉/?CA?₁₉,?CA?₁₉/?CA?₂₀0 and?CA?₂₀/?CA?₂₀;of whiche,the frequency of?CA?₁₈/?CA?₁₈,?CA?₁₈/?CA?₁₉9 and?CA?₁₉/?CA?₁₉9 genotype were higher than others,0.23,0.27,and 0.16,respectively.The microsatellite locus in the promoter region?CA?_n ofIGF1 gene was not in Hardy-Weinberg equilibrium?p>0.05?.Correlation analysis with growth traits of Landrace showed that genotype?CA?₁₉/?CA?₁₉9 was generally better than others in growth traits such as body length,115kg body weight,and eye muscle area.?3?Construction of four haplotype?CA?₁₇-11T,?CA?₁₈-11T,?CA?₁₉-11T and?CA?₂₀-11T dual luciferase reporter vectors transfected into porcine myoblasts and the transcriptional activity of?CA?₁₉-11T was the highest,which was significantly higher than?CA?₁₇-11T?p<0.05?.?4?In conclusion,the correlation analysis between different genotype combinations?CA?_n-T_n in the promoter region of IGF1 gene and growth traits of landrace showed that genotype combinations?CA?₁₉/?CA?₁₉-11T/11T were more conducive to the growth of landrace.