Polymorphism of Melanocortin-4 Receptor Gene and Its Association with Growth Traits in Bali Cattle

Abstract

The melanocortin-4 receptor (MC4R) is a gene that controls growth traits.  This gene is embedded in the leptin-melanocortin pathway and regulates body weight.  Previous studies have successfully identified the genetic diversity of the MC4R associated with growth traits.  However, studies on Bali cattle are limited.  This study aimed to identify the SNP markers of the MC4R gene and its effect on birth body weight, weaning body weight, weaning chest girth, weaning withers height, weaning body length, yearling body weight, yearling chest girth, yearling withers height, and yearling body length in Bali cattle (n=43).  The MC4R genotype was identified by sequencing and aligned using BioEdit v.7.2.5.  The association between genotype and growth traits was analyzed using the GLM procedure and DMRT in RStudio program v.2022.02. Four SNPs were identified in the exon region:  g.355GT, g.394CT, g.463GA, and g.682GA.  Based on the Chi-square test, the population was fitted with HWE (p0.05).  Genotype-phenotype association based on SNPs showed no significant result (p0.05) where the g.682GA (AG) locus had values of WB (104.33+17.15 kg), WCG (112.83+3.66 kg), WBL (89.50+3.94 kg), YB (124.17+22.44 kg), YCG (120.50+5.50 kg), and YBL (92.83+4.31 kg) higher than the other genotypes.  Association based on haplotype type showed significant results (p0.05) in BB, where haplotype 2 had the highest BB (21.17+0.75 kg).  In conclusion, the SNP markers found in this study were polymorphic but did not affect growth traits in Bali cattle.