KRTAP36-1基因在子午岭黑山羊中的鉴定及其与羊绒性状的关联分析

Identification of caprine KRTAP36-1 and its association with cashmere traits in Ziwuling black goats

为鉴定子午岭黑山羊KRTAP36-1基因,并分析其与羊绒性状的相关性,以绵羊KRTAP36-1基因编码区序列为模板,利用GenBank的BLAST功能,在山羊染色体上进行同源性搜索,用聚合酶链反应-单链构象多态性(Polymerase chain reaction-single strand conformation polymorphism,PCR-SSCP)和测序方法,检测342只子午岭黑山羊上的核苷酸序列变异,最后用一般线性混合效应模型分析序列变异与羊绒性状的相关性。结果表明,在342只子午岭黑山羊上检测到3条不同的核苷酸序列(命名为A、B和C),进化树发现这3条序列与绵羊KRTAP36-1序列有最高的同源性,表明这些序列来自于山羊KRTAP36-1基因。测定结果表明,山羊KRTAP36-1基因有2个SNPs,其中一个(c.119A/G)为错义突变,导致p.Tyr40Cys的氨基酸改变。相关性分析表明,KRTAP36-1核苷酸序列A的存在与子午岭黑山羊较小的产绒量相关(P<0.001),B的存在与较大的产绒量相关(P=0.004),BB型个体的产绒量高于AB型和AA型个体(P<0.001)。KRTAP36-1的核苷酸序列变异对子午岭黑山羊的羊绒平均纤维直径和绒层高度无影响(P>0.05)。综上,KRTAP36-1基因可以作为子午岭黑山羊羊绒性状的分子标记,用于提高该群体的产绒量。

The aim of our study was to identify caprine KRTAP36-1 in goat genome and investigate its association with cashmere traits.By taking the coding sequence of ovine KRTAP36-1 as template,similar sequences in the caprine genome was searched using BLAST funtion in GenBank.Nucleotide sequence variations in 342 Ziwuling black goats were detected using PCR-SSCP analysis and Sanger sequencing,and the association variation in the gene with variation in cashmere traits was finally analyzed using general liner mixed-effect models.Three different nucleotide sequences(named variants A,B,and C)were detected in 342 Ziwuling black goats.The phylogenetic tree analysis showed that the three sequences had the highest homology with the KRTAP36-1 sequence from sheep,suggesting that the sequences identified in this study were originated from caprine KRTAP36-1.Two SNPs were detected in the gene and c.119 A/G was a non-synonymous SNP,which would cause the amino acid change of p.Tyr40 Cys.The presence of variant A was associated with decreased cashmere fiber weight(P<0.001),while the presence of variant B was associated with increased cashmere fiber weight(P=0.004).The goats with BB had higher cashmere fibre weight than those of AB and AA(P<0.001).The nucleotide sequence variation of KRTAP36-1 had no effect on the average fibre diameter and cashmere layer height of Ziwuling black goats.No associations with mean fiber diameter and curly fiber length were detected for variation in caprine.These results indicated that caprine KRTAP36-1 gene can be used as a molecular marker for improving cashmere fibre weight in Ziwuling black goats.