Genome-wide association study for wool production traits in a Chinese Merino sheep population.

Zhipeng Wang,Enguang Rong,Ning Wang,Shouzhi Wang,Wenyu Pei,Hui Li,Hui Zhang,Hua Yang,Qin Zhang

doi:10.1371/journal.pone.0107101

Abstract

Genome-wide association studies (GWAS) provide a powerful approach for identifying quantitative trait loci without prior knowledge of location or function. To identify loci associated with wool production traits, we performed a genome-wide association study on a total of 765 Chinese Merino sheep (JunKen type) genotyped with 50 K single nucleotide polymorphisms (SNPs). In the present study, five wool production traits were examined: fiber diameter, fiber diameter coefficient of variation, fineness dispersion, staple length and crimp. We detected 28 genome-wide significant SNPs for fiber diameter, fiber diameter coefficient of variation, fineness dispersion, and crimp trait in the Chinese Merino sheep. About 43% of the significant SNP markers were located within known or predicted genes, including YWHAZ, KRTCAP3, TSPEAR, PIK3R4, KIF16B, PTPN3, GPRC5A, DDX47, TCF9, TPTE2, EPHA5 and NBEA genes. Our results not only confirm the results of previous reports, but also provide a suite of novel SNP markers and candidate genes associated with wool traits. Our findings will be useful for exploring the genetic control of wool traits in sheep.

Highlights

Sheep (Ovis aries) are one of the earliest domesticated animals
In the field of sheep breeding for high wool quality, it is difficult to accurately evaluate the genetic component for wool quality traits since the phenotypes of these traits are difficult to be measured
47,286 single nucleotide polymorphisms (SNPs) with minor allele frequencies (MAF) of 5% or greater and call rates of 95% or greater were selected for use in this study

Summary

Introduction

Sheep provide humans with a source of meat, milk, wool, and skins, and play a vital role in the global agricultural economy. The Merino sheep is an economically influential breed of sheep prized for its wool. Merino wool is regarded as the finest and softest wool of any sheep. Wool quality traits, such as fiber diameter, length and strength, are important goals in Merino breeding programs. Most countries have high-quality performance measurement programs and well-developed tools for index selection using best linear unbiased prediction (BLUP). In the field of sheep breeding for high wool quality, it is difficult to accurately evaluate the genetic component for wool quality traits since the phenotypes of these traits are difficult to be measured

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