Correlation analysis between polymorphism of leptin and IGFI genes and body measurements in Barki and Farafra sheep

Abstract

Background Growth performance, which can be evaluated using various body measurements, is crucial for providing red meat for human consumption. This study aims to improve the growth performance of sheep by identifying the different genotypes of leptin and IGFI genes associated with higher body measurements. Methods In this study, we collected blood samples from Barki (n = 30) and Farafra (n = 30) sheep, and measured their body height, width, length, and weight, and tail width and length to assess their growth performance. We used single strand conformation polymorphism polymerase chain reaction (SSCP-PCR) and sequencing analysis to identify single nucleotide polymorphisms (SNPs) and different genotypes of the leptin and insulin-like growth factor receptor (IGFI) genes associated with sheep body measurements. Results The leptin gene (209 bp) and IGFR gene (345 bp) were found to have three (TT, TG, and GG) and (TT, TC, and CC) genotypes, respectively, by SSCP-PCR. Sequence analysis revealed a SNP in the leptin gene (200G > T) with two alleles (G allele: OR058867 and T allele: OR058868). This SNP resulted in the substitution of the amino acid valine with leucine, which increased the width, length, and weight of the body and tail width in the heterozygous form (TG). The IGFI gene had three SNPs: 305 G > T in TT genotype (OR260670), 184C > T, 265T > C, and 305G > T in TC genotype (OR260669), and 265T > C in CC genotype (OR260671). The TC genotype of the IGFR gene was correlated with higher values of body measurements. Barki sheep were found to have the highest values for body weight, width, length, and tail width compared to Farafra sheep. Conclusion We recommend the use of entire Barki sheep in inbreeding programs to improve growth performance in Egyptian sheep.