Sulayman Ablat, Tursun Mahira, Sulaiman Yiming, Huang Xixia, Tian Kechuan, Tian Yuezhen, Xu Xinming, Fu Xuefeng, Mamat Amat, Tulafu Hanikezi
College of Animal Science, Xinjiang Agricultural University, Urumqi 830052, China.
Xinjiang Academy of Animal Science, Urumqi 830000, China.
Asian-Australas J Anim Sci. 2018 Jun;31(6):775-783. doi: 10.5713/ajas.17.0349. Epub 2017 Nov 3.
The purpose of this study was to investigate the genetic effects of six keratin () genes on the wool traits of 418 Chinese Merino (Xinjiang type) (CMXT) individuals.
To explore the effects and association of six genes on sheep wool traits, The polymerase chain reaction-based single-strand conformation polymorphism (PCR-SSCP), DNA sequencing, and the gene pyramiding effect methods were used.
We report 20 mutation sites (single-nucleotide polymorphisms) within the six genes, in which twelve induced silent mutations; five induced missense mutations and resulted in Ile→Thr, Glu→Asp, Gly→Ala, Ala→Ser, Se→His; two were nonsense mutations and one was a same-sense mutation. Association analysis showed that two genotypes of the gene were significantly associated with fiber diameter (p<0.05); three genotypes of the gene were significantly associated with wool fineness score and fiber diameter (p<0.05), three genotypes of the gene were significantly associated with the number of crimps (p< 0.05); and three genotypes of the gene were significantly associated with wool crimps score, body size, and fiber diameter (p<0.05). Analysis of the gene pyramiding effect between the different genotypes of the gene loci , , and , each genotype in a gene locus was combined with all the genotypes of another two gene loci and formed the different three loci combinations, indicated a total of 26 types of possible combined genotypes in the analyzed population. Compared with the other combined genotypes, the combinations CC-GG-II, CC-HH-IJ, CC-HH-JJ, DD-HH-JJ, CC-GH-IJ, and CC-GH-JJ at gene loci , , and , respectively, had a greater effect on wool traits (p<0.05).
Our results indicate that the mutation loci of , , , and genes, as well as the combinations at gene loci , , and in CMXT have significant effects on wool traits, suggesting that these genes are important candidate genes for wool traits, which will contribute to sheep breeding and provide a molecular basis for improved wool quality in sheep.
本研究旨在探究6个角蛋白（）基因对418只中国美利奴羊（新疆型）（CMXT）羊毛性状的遗传效应。
为探究6个基因对绵羊羊毛性状的影响及关联性，采用了基于聚合酶链反应的单链构象多态性（PCR - SSCP）、DNA测序及基因累加效应方法。
我们在6个基因中报道了20个突变位点（单核苷酸多态性），其中12个诱导产生沉默突变；5个诱导产生错义突变，导致异亮氨酸→苏氨酸、谷氨酸→天冬氨酸、甘氨酸→丙氨酸、丙氨酸→丝氨酸、丝氨酸→组氨酸；2个为无义突变，1个为同义突变。关联分析表明，基因的两种基因型与纤维直径显著相关（p<0.05）；基因的三种基因型与羊毛细度评分和纤维直径显著相关（p<0.05），基因的三种基因型与卷曲数显著相关（p<0.05）；基因的三种基因型与羊毛卷曲评分、体型和纤维直径显著相关（p<0.05）。对基因座、和不同基因型之间的基因累加效应进行分析，一个基因座的每种基因型与另外两个基因座的所有基因型组合，形成不同的三个基因座组合，结果表明在分析群体中共有26种可能的组合基因型。与其他组合基因型相比，基因座、和上的组合CC - GG - II、CC - HH - IJ、CC - HH - JJ、DD - HH - JJ、CC - GH - IJ和CC - GH - JJ分别对羊毛性状有更大影响（p<0.05）。
我们的结果表明，CMXT中、、和基因的突变位点，以及基因座、和上的组合对羊毛性状有显著影响，表明这些基因是羊毛性状的重要候选基因，这将有助于绵羊育种，并为提高绵羊羊毛品质提供分子基础。
