牛αS1酪蛋白基因变异及其与生产性状的关系

Polymorphism within Bovine αS1 Casein Gene and its Associations with Production Traits

中文关键词: 牛αS1酪蛋白  变异体  多态性  生产性状  Bovine αS1 casein

英文关键词: Variants  Polymorphisms  Production traits

中文摘要:

      αS1酪蛋白是牛乳中含量最高的蛋白,其基因的多态类型会影响奶牛的产奶性状和牛乳的一些加工特性,人们已经对其进行了广泛研究.牛αS1酪蛋白基因编码区全长17 508 bp(不计启动子序列),由19个外显子和18个内含子构成,外显子与内含子长度比例为1∶14.4.尽管其编码区突变率较高,但侧翼序列比较保守.到目前为止,牛αS1酪蛋白共发现有9种变异体,由核苷酸非同义替换、插入或缺失及外显子跳跃造成.牛αS1酪蛋白蛋白质序列及DNA序列的高度差异性揭示其编码基因可能是一个高速进化的基因家族.αS1酪蛋白基因与泌乳性状之间的关联性可以用基因调控区,特别是转录因子结合位点存在突变位点来解释.但是,有关牛αS1酪蛋白基因变异体还存在一些未探明的结果,因此,阐明其基因的结构特点并进一步揭示它们与生产性状之间的关系是非常必要的.

英文摘要:

      αS1 casein is the major protein fraction in bovine milk. The extensive polymorphism at αS1 -CN is likely responsible for the quantitative and qualitative differences in milk and the processing characteristic of dairy products which has been extensively studied in cattle. The encoding region of this gene consists of 19 exons and 18 introns extending over 17 508 bp from the start point of transcription. divergence of coding regions, its flanking sequence is conserved. Nine variants of αS1 casein have been identified in Bos, which are caused by the non-synonymous substitution, indels and exon skipping. Quite divergent sequences for the mature proteins and DNA of αS1 -CN suggest that they are encoded by a rapidly evolving gene family. The association of αS1 casein gene with milk traits can be explained by the existence of mutations in the regulatory region in this gene, especially in the transcription factor binding sites. However, there are still some unproved results. It is necessary to clarify the genetic structure and to reveal their associations with production traits.