Variation in the caprine keratin-associated protein 15-1 (KAP15-1) gene affects cashmere fibre diameter

Mengli Zhao; Huitong Zhou; Jon G H Hickford; Hua Gong; Jiqing Wang; Jiang Hu; Xiu Liu; Shaobin Li; Zhiyun Hao; Yuzhu Luo

doi:10.5194/aab-62-125-2019

Variation in the caprine keratin-associated protein 15-1 (KAP15-1) gene affects cashmere fibre diameter

Arch Anim Breed. 2019 Mar 26;62(1):125-133. doi: 10.5194/aab-62-125-2019. eCollection 2019.

Authors

Mengli Zhao^{1

2}, Huitong Zhou^{1

2

3}, Jon G H Hickford^{1

2

3}, Hua Gong^{2

3}, Jiqing Wang^{1

2}, Jiang Hu^{1

2}, Xiu Liu^{1

2}, Shaobin Li^{1

2}, Zhiyun Hao^{1

2}, Yuzhu Luo^{1

2}

Affiliations

¹ Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
² International Wool Research Institute, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
³ Gene-Marker Laboratory, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand.

Abstract

Keratin-associated proteins (KAPs) are a structural component of cashmere fibre, and variation in some KAP genes (KRTAPs) has been associated with a number of caprine fibre traits. In this study, we report the identification of KRTAP15-1 in goats. Sequence variation in the gene was detected using the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) technique in 250 Longdong goats, and six variants (named A to F) containing eight single nucleotide polymorphisms (SNPs) were identified. Five of the SNPs were non-synonymous and would lead to putative amino acid changes. Reverse-transcription polymerase chain reaction (RT-PCR) analysis revealed that KRTAP15-1 was expressed in secondary hair follicles but not in heart tissue, liver tissue, lung tissue, kidney tissue or the longissimus dorsi muscle. Despite being rich in cysteine, the caprine KAP15-1 protein possesses a high content of serine and moderate content of glycine and phenylalanine. Association analyses revealed that KRTAP15-1 variant A was associated with decreased mean fibre diameter (MFD), and this effect appeared to be dominant; while variant C was found to be associated with increased MFD, the effect being recessive. The findings suggest that caprine KRTAP15-1 is highly polymorphic and that variation in this gene affects cashmere MFD.