Nucleotide Sequence Variation in the Insulin-Like Growth Factor 1 Gene Affects Growth and Carcass Traits in New Zealand Romney Sheep.

Shaobin Li,Yuzhu Luo,Fangfang Zhao,Jiqing Wang,Huitong Zhou,Qian Fang,Jon G.H Hickford,Xiu Liu

doi:10.1089/dna.2020.6166

Abstract

Insulin-like growth factor 1 (IGF1) is a mediator of the effects of growth hormone and polymorphism in the IGF1 gene (IGF1) is reported to affect fat deposition in some livestock species. In this study, nucleotide sequence variation in three regions of ovine IGF1 (part of the 5′ flanking region, the exon 3 region, and the exon 4 region) was investigated in 848 New Zealand Romney lambs using PCR-single strand conformation polymorphism (SSCP) analyses to ascertain if single nucleotide polymorphisms (SNPs) existed. Six SNPs were identified across these three regions. The effect of the sequence variation in the exon 3 and exon 4 regions on growth and carcass traits were investigated. One of the PCR-SSCP sequence variants in the exon 3 region was associated with variation in hot carcass weight, carcass fat depth at the 12th rib measured using video imaging and the percentage proportion of leg lean meat, whereas the other was associated with variation in growth rate to weaning. No associations were detected for the other gene regions analyzed. The results suggest that polymorphism in exon 3 of ovine IGF1 has potential for use as a gene-marker for some carcass and growth traits.

Highlights

Insulin-like growth factor 1 (IGF1) is encoded by the IGF1 gene (IGF1) ( Jansen et al, 1983; Hoppener et al, 1985)
Two unique PCR-single strand conformation polymorphism (SSCP) banding patterns were detected in each region of ovine IGF1, with either one or a combination of two banding patterns observed for each sheep (Fig. 1)
There was only a single synonymous single nucleotide polymorphisms (SNPs) detected in the coding region of IGF1, which is in agreement with the observation that IGF1 is conserved among mammals and that the IGF1 protein, along with IGF2 and insulin, comprise a conserved protein family found in most mammalian species and in many other vertebrates (Rotwein, 2017)

Summary

Introduction

Insulin-like growth factor 1 (IGF1) is encoded by the IGF1 gene (IGF1) ( Jansen et al, 1983; Hoppener et al, 1985) It has ‘‘non-suppressible insulin-like activity’’ (Salmon and Daughaday, 1957) and is a primary mediator of the effects of growth hormone. Exons 1 and 2 determine the class of the protein and encode the signal peptide for cellular localization after translation, whereas exons 3 and 4 primarily encode the mature IGF1 peptide. This becomes the receptor-binding ligand (Rotwein, 2012)

Methods

Results

Conclusion