RAI14in the blood featherregulates chicken pigmentation.

Adeyinka Abiola Adetula,Liubin Yang,Hui Yu,Xiaolei Liu,Hua Li,Chengchi Fang,Shijun Li

doi:10.5194/aab-63-231-2020

Abstract

A genome-wide association study (GWAS) was performed on a resource family consisting of white and colored chickens for identification of genes related to plumage coloration using the Fixed and random model Circulating Probability Unification (FarmCPU) package. GWAS identified three chromosomal single-nucleotide polymorphisms (SNPs), demonstrating the polygenic basis of plumage phenotypes. Herein, retinoic acid-induced protein 14 (RAI14), a developmentally regulated gene that encodes a protein containing many ankyrin repeats, was identified as a candidate gene involved in plumage color. In this study, mRNA expression profiles of chicken RAI14 were determined, indel (insertion–deletion) variants were identified, and their association was analyzed in white and colored chickens. RA114 mRNA was expressed in all tissues tested (brain, spleen, liver, heart, oviduct, kidney, lung, pituitary gland, ovary, muscle, feather bulb, and skin). A relatively high RAI14 expression in white feather bulb compared to colored feather bulb () indicated a potential association with plumage color. Additionally, statistical analysis revealed that a 4 bp indel genetic variation in RAI14 was associated with plumage phenotypes (). Together, our analysis of the identification of the RAI14 gene will enable us to understand the genetic mechanisms behind chicken pigmentation.

Highlights

Color is an important feature of the majority of living organisms
We have focused on the Z chromosome due to strong associations that include single-nucleotide polymorphisms (SNPs) linked to retinoic acid-induced protein 14 (RAI14), a gene involved in plumage coloring
As a result of a genome-wide association study (GWAS) conducted for white and colored chickens using Fixed and random model Circulating Probability Unification (FarmCPU) methods (Liu et al, 2016b), three quantitative trait loci (QTLs) at a genome-wide significant level were found to be associated with the plumage traits (Fig. 2)

Summary

Introduction

Color is an important feature of the majority of living organisms. In poultry, complete white is characterized by a uniform, pure white color across all feathers, which is generally associated with no visible pigment, while colored chickens are mainly characterized by the distribution of two melanin pigments: eumelanin (black, gray, and brown colors) and pheomelanin (reddish-brown colors). Genetic studies have shown that mutations in the premelanosome protein (PMEL17) gene have been associated with dominant white (Kerje et al, 2004), and five mutations in the solute carrier family 45 member 2 (SLC45A2) have been associated with the silver color in chicken (Gunnarsson et al, 2007). Dark brown, and sex-linked barring patterns were associated with mutations in the coding region of the melanocortin receptor 1 (MC1R) gene (Kerje et al, 2003). The dark brown plumage is caused by a 8.3 kb deletion upstream of SOX10 (Gunnarsson et al, 2011), and sexlinked barring is controlled by the cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) locus (Hellström et al, 2010), suggesting that nucleotide polymorphism plays a significant

Methods

Results

Discussion

Conclusion