Polymorphisms of IGF-IR gene and their association with economic traits in two indigenous Chinese dairy goat breeds

The effect of insulin-like growth factor 1 receptor gene single nucleotide polymorphism on growth and milk production traits in two native Indian tropical goat breeds

Insulin like growth factor1(IGF-1) is an essential growth factor that mediates the growth-promoting functions of pituitary growth hormone. Insulin like growth factor 1 receptor (IGF1R) is a tyrosine kinase receptor that mediates the actions of IGF1. Therefore, IGF1R is a candidate gene for examining SNPs linked with growth and production traits. The objective of this study was to detect the c.546 + 179170A > T transversion in intron 2 of the gene encoding IGF1R in two goat breeds, Attappady Black and Malabari, and examine the association of this polymorphism with growth and milk production. For the identification of the SNP, the T-ARMS-PCR was utilized. All three genotypes were present in the two investigated breeds. The polymorphism was found to be significantly (p < 0.05) linked with growth traits. At birth, 3 and 6 months of age, Attappady goats with the AT genotype had significantly (p < 0.05) higher body weights than those with the AA and TT genotypes. Malabari goats with the AT genotype had significantly (p < 0.05) higher body weights at birth and at 3 months of age. The genotypes of the IGF1R gene had no effect on total or peak milk production. Therefore, this SNP could be used as a molecular marker in selection of meat-producing goat breeds.HIGHLIGHTSc.546 + 179170A > T IGF1R transversion was detected using T-ARMS-PCR in two indigenous goat breeds from Kerala.Attappady Black and Malabari goat breeds of Kerala possessed all the three genotypesIn these breeds, there was a significant correlation between this SNP, c.546 + 179170A > T IGF1R, and body weight.In both the breeds, there was no association between this SNP and milk production traits.

Genetic Polymorphisms of IGF1 and IGF1R Genes and Their Effects on Growth Traits in Hulun Buir Sheep

The identification of candidate genes and genetic variations associated with growth traits is important for sheep breeding. Insulin like growth factor 1 (IGF1) and insulin like growth factor 1 receptor (IGF1R) are well-accepted candidate genes that affect animal growth and development. The current study attempted to assess the association between IGF1 and IGF1R genetic polymorphisms and growth traits in Hulun Buir sheep. To achieve this goal, we first identified three and ten single nucleotide polymorphisms (SNPs) in exons of IGF1 and IGF1R in Hulun Buir sheep and then constructed six haplotypes of IGF1R based on linkage disequilibrium, respectively. Association studies were performed between SNPs and haplotypes of IGF1 and IGF1R with twelve growth traits in a population encompassing 229 Hulun Buir sheep using a general linear model. Our result indicated three SNPs in IGF1 were significantly associated with four growth traits (p < 0.05). In IGF1R, three SNPs and two haplotype blocks were significantly associated with twelve growth traits (p < 0.05). The combined haplotype H5H5 and H5H6 in IGF1R showed the strong association with 12 superior growth traits in Hulun Buir sheep (p < 0.05). In conclusion, we identified SNPs and haplotype combinations associated with the growth traits, which provided genetic resources for marker-assisted selection (MAS) in Hulun Buir sheep breeding.

Association of a polymorphism in exon 3 of the IGF1R gene with growth, body size, slaughter and meat quality traits in Colored Polish Merino sheep

This study aimed to genotype the polymorphism (c.654G > A) in the exon 3 of the insulin-like growth factor 1 receptor gene (IGF1R) and to analyze its association with growth, body size, slaughter and meat quality traits in Colored Polish Merino sheep. In total, 67 traits were analyzed. The IGF1R polymorphism was genotyped using the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) method. The MIXED procedure of the SAS software was used to assess the genotypic effects of the polymorphism (c.654G > A) on production traits of interest. The IGF1R c.654G > A genotypes were found to have a significant effect on the average daily gain between the 56th and 78th day of life, cold carcass, leg part, leg cut, fore shank, and kidney weights, as well as eye of loin depth, intramuscular fat content, and water-holding capacity of meat. The results suggest that the studied polymorphism may provide useful information for marker-assisted selection for increased meat performance in Colored Polish Merino sheep.