Detection of Snps in the Melanocortin 1-Receptor (MC1R) and Its Association with Shank Color Trait in Hs Chicken

X Shen,C Cui,M Qiu,C Yu,Y Wang,H Yin,H Du,X Jiang,C Yang,Z Zhang,X Zhao,Q Li,Q Zhu,D Li

doi:10.1590/1806-9061-2018-0845

Abstract

ABSTRACT The melanocortin 1 receptor (MC1R) gene plays a key role in controlling the deposition of melanin. In mammals, the MC1Rgene is regarded as a major candidate gene in the control of melanin formation. In domestic animals, the MC1R gene mainly controls the expression of coat, skin, and plumage color in mammals and birds. In order to breed chickens with dark-green shank faster, we screened the molecular markers for shank color in a HS chicken population by exploring the relationship between polymorphism of the MC1R gene and three different shank colors (light green, dark green and yellow). Two primer pairs for code region of the MC1R gene were designed in the basic of chicken genomic sequence. DNA sequencing was performed to detect the polymorphisms and PCR was used to amplify DNA fragment. Sequences analysis indicated that 7 SNPs were predominant the three HS chicken populations with different shank color, including g.18,287,945C>T, g.18,288,088T>C, g.18,288,150G>A, g.18,288,303A>G, g.18,288,512G>A, g.18,288,513T>C, and g.18,288,520A>C. Association analysis revealed that the dark-green shank population showed moderate polymorphism, whereas the light-green shank population showed low polymorphism among overall 7 SNPs and that SNP6 (g.18,288,513T>C) may be significantly associated with three different shank colors in HS chickens. The haplotype CTGGACA had the largest haplotype frequencies, accounting for 56.22%, and the haplotype combination H1H1 is mainly distributed in the dark-green shank population, and may be used as molecular maker for marker-assisted selection of shank color in HS chickens.

Highlights

Animals display a wide variety of coat or skin colors, which depend on the black-brown eumelanin to yellow-reddish phaeomelanin in the skin (Wang & Hebert 2006)
Shank color is the very important phenotypic quantitative trait in Chinese indigenous chicken breeding, as it directly determines the competitiveness of new chicken species in the consumer market
The melanocortin-1 receptor (MC1R) gene has been extensively studied in human melanoma

Summary

Introduction

Animals display a wide variety of coat or skin colors, which depend on the black-brown eumelanin to yellow-reddish phaeomelanin in the skin (Wang & Hebert 2006). The melanocortin-1 receptor (MC1R) gene, with its ligands melanocortins and ACTH, is the main positive regulator (Slominski et al, 2004). The cytogenetic location of the MC1R gene is the long (q) arm of chromosome 16 at position 24.3 and mainly controls which type of melanin is produced by melanocytes (García-Borrón et al, 2005). When the MC1R gene is activated by external factors, a series of chemical reactions are triggered inside melanocytes, stimulating the production of eumelanin (Ha et al, 2003). As early as 2001, it was found that MC1R gene variants predispose to cutaneous melanoma (Kennedy et al, 2001). Most studies on the MC1Rgene linked to cancer showed that MC1R germline mutations that determine light skin color and red hair phenotypes increase the risk of melanoma (Mundra et al, 2017). The study of Tagliabue et al (2018) determined eRBCA-2018-0845

Methods

Results

Conclusion