Abstract:
α-keratins are structural proteins in the cortex of wool fibres and assemble in an organized fashion into keratin intermediate filaments. Variation in these keratin proteins affects the structure and characteristics of wool fibre, making keratin genes ideal candidates for the development of gene markers that describe variations in wool traits. A region of KRT85 spanning exon 3-4 (including the entire exon 3, intron 3, exon 4 and part of intron 4) was investigated. Two banding patterns defining two variant sequences (A and B) were observed in this region, and these were characterised by the presence of two single nucleotide polymorphisms. The effect of this variation in the exon 3-4 region of KRT85 on wool traits was investigated in 463 Merino × Southdown-cross lambs. The frequencies of these two variants in these sheep were 55.6% and 44.4%, respectively. Three different genotypes were observed with frequencies of 32.6%, 46.1% and 21.3% for AA, AB and BB, respectively. The presence of A was associated with an increase in greasy fleece weight and clean fleece weight, while the presence of B was associated with an increased wool prickle factor. These findings should be replicated in a broader range of sheep breeds to determine whether the associations are robust and to clarify whether the observed effects are attributable to breed differences or to gene effects themselves.
摘要:
α-角蛋白是羊毛纤维皮层中的结构蛋白,并以有组织的方式组装成角蛋白中间丝。这些角蛋白的变化会影响羊毛纤维的结构和特性,使角蛋白基因成为开发描述羊毛性状变异的基因标记的理想候选者。研究了KRT85的跨越外显子3-4的区域(包括整个外显子3、内含子3、外显子4和部分内含子4)。在该区域中观察到定义两个变体序列(A和B)的两个条带模式。这些特征是存在两个单核苷酸多态性。在463只Merino×Southdown杂交羔羊中研究了KRT85外显子3-4区域的这种变异对羊毛性状的影响。这两种变异在这些绵羊中的频率分别为55.6%和44.4%,分别。观察到三种不同的基因型,频率为32.6%,AA的46.1%和21.3%,AB和BB,分别。A的存在与油腻羊毛重量和干净羊毛重量的增加有关,而B的存在与羊毛刺因子的增加有关。这些发现应在更广泛的绵羊品种中复制,以确定这种关联是否牢固,并阐明观察到的影响是归因于品种差异还是基因效应本身。