Variation in a Newly Identified Caprine KRTAP Gene Is Associated with Raw Cashmere Fiber Weight in Longdong Cashmere Goats.

Mengli Zhao,Shaobin Li,Jiang Hu,Yuzhu Luo,Xiu Liu,Kaiwen Zhang,Jon G H Hickford,Jiqing Wang,Huimin Zhen,Huitong Zhou

doi:10.3390/genes12050625

Abstract

Keratin-associated proteins (KAPs) and keratins determine the physical and chemical properties of cashmere fibers as they are the main components of the fibers. It has been reported that ovine KRTAP1-2 affects clean fleece weight, greasy fleece weight and yield in sheep, but the gene has not been described in goats and its effects on fiber traits are unknown. In this study, we identify the keratin-associated protein 1-2 gene (KRTAP1-2) in the goat genome and describe its effect on cashmere fiber traits in 359 Longdong cashmere goats. Six sequence variants (named CAPHI-KRTAP1-2*A to CAPHI-KRTAP1-2*F) were revealed using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. These sequences have the highest homology with ovine KRTAP1-2 sequences. There were a 60-bp deletion, a 15-bp insertion and five single nucleotide polymorphisms (SNPs) including two non-synonymous SNPs in the coding sequence. The caprine KRTAP1-2 gene was expressed in the skin tissue, but a signal was not observed for the kidneys, liver, lungs, spleen, heart and longissimus dorsi muscle. Variation in caprine KRTAP1-2 was found to be associated with raw cashmere fiber weight, but not with fiber diameter and length.

Highlights

Introduction iationsThe Longdong cashmere goat is a special breed of goat farmed in the Longdong area of the Gansu Province
This study has identified a new caprine KRTAP and describes variation in this gene including the presence of single nucleotide polymorphisms (SNPs), insertions and deletions
The newly identified caprine KRTAP sequences were phylogenetically closest to ovine KRTAP1-2 and was located in the same chromosomal region as caprine KRTAP13 and KRTAP1-4, suggesting that these new KRTAP sequences represent variants of caprine KRTAP1-2

Summary

Introduction

The Longdong cashmere goat is a special breed of goat farmed in the Longdong area of the Gansu Province. This breed has been created as a cross between the Ziwuling black goat, the Inner Mongolian cashmere goat and the Liaoning cashmere goat While the Longdong cashmere goat is well-adapted to harsh environments including desert and other arid regions, it has lower cashmere fiber yields (average of 400 g per annum) than the Liaoning cashmere goat (average of 640 g) and the Inner. The identification and understanding of genes that regulate cashmere fiber growth and structure is important for improving the yield of cashmere fiber in Longdong cashmere goats.

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