The polymorphism of insulin-like growth factor-1 receptor (IGF-1R) gene in meat-type Lambs in Turkey: I. Effect on growth traits and body measurements

As an important tyrosine kinase activator, insulin-like growth factor-1 receptor (IGF-1R) is activated by IGF-1 and IGF-2 and is a cell surface protein that functionally regulates cell growth and proliferation. This study was conducted to investigate the association between the previously determined single nucleotide polymorphism (SNP; g 0.195C > T) in the IGF-1R gene with growth and skeletal development traits of meat-type lambs. Different sheep breeds and their crosses were involved in the study, and data were collected from a total of 159 lambs (62 males and 97 females). The selected region in IGF-1R was analyzed using PCR-RFLP and the SNP 0.195C > T substitution was detected. Subsequently, three genotypes were determined for this genetic variation: AA (0.197), AB (0.493), and BB (0.310). The associations between the identified genotypes and growth traits were evaluated for the period from birth to PS (pre-slaughter). Statistical analysis showed that IGF-1R genotypes had a significant effect on birth weight (P < 0.01) and daily weight gain on day 90-PS (P < 0.05). Similarly, the effects of genotype on body measurements, withers height and back height were significant (P < 0.05). In trasound measurements, longissimus dorsi (LD) muscle depth, skin thickness, and fat thickness were not sig-nificant. The data obtained in this study show that the variation of IGF-1R gene has a significant effect on the growth characteristics of lambs. Therefore, the use of this gene as a genetic marker in the production of lambs slaughter may lead to more profitable production.