Identification of the Caprine Keratin-Associated Protein 20-2 (KAP20-2) Gene and Its Effect on Cashmere Traits

• Main Authors: Jiqing Wang, Longjie Che, Jon G. H. Hickford, Huitong Zhou, Zhiyun Hao, Yuzhu Luo, Jiang Hu, Xiu Liu, Shaobin Li
• Format: Article
• Language: English
• Published: MDPI AG 2017-11-01
• Series: Genes
• Subjects: cashmere fibre weight; keratin-associated protein 20-2 (KAP20-2) gene; length of the curly fibre; Longdong cashmere goat; tissue expression; variation
• Online Access: https://www.mdpi.com/2073-4425/8/11/328

The gene encoding the high glycine/tyrosine keratin-associated protein 20-2 (KAP20-2) gene has been described in humans, but has not been identified in any livestock species. A search for similar sequences in the caprine genome using the human KAP20-2 gene (KRTAP20-2) revealed a homologous sequence on chromosome 1. Three different banding patterns representing distinct sequences (A–C) in Longdong cashmere goats were identified using polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) analysis. These sequences shared high sequence similarity with the human and mouse KRTAP20-2 sequences, suggesting that A–C are caprine variants of the human and mouse genes. Four single nucleotide polymorphisms (SNPs) were identified, and three of them were non-synonymous. KRTAP20-2 was found to be expressed in secondary hair follicles, but not in heart, liver, lung, kidney, spleen, or longissimus dorsi muscle. The presence of A was associated with increased cashmere fibre weight, while the presence of B was associated with a decrease in cashmere fibre weight and curly fibre length. Goats with genotype AA had a higher cashmere fibre weight and a higher curly fibre length than those with genotypes AB or BB. These results indicate that caprine KRTAP20-2 variation may have value as a genetic marker for improving cashmere fibre weight.