Six1基因启动子区（CA）n微卫星多态对猪肉质性状的影响及作用机制研究

Six1基因在肌肉的生长发育与肌纤维类型的转变中发挥着重要作用，是一个影响猪肉质性状的重要候选基因。另外，微卫星是一类非常重要的调控元件，参与了生物的各种生命活动。有趣的是，猪Six1基因启动区存在一个（CA）n微卫星，并在皮×杜×长×大F2代资源群中存在长度变异。但该微卫星变异与猪肉质性状的关系，以及对Six1基因转录表达的作用机制尚不清楚。本项目首先对（CA）n微卫星在皮×杜×长×大F2代资源群中遗传多样性进行分析，并对其多态性与猪肉质性状进行关联分析。进一步，通过体内与体外实验验证（CA）n微卫星变异对Six1基因表达的影响，并对其影响Six1基因表达的分子机制进行探究。本项目的开展，一方面可开发出潜在的影响猪肉质性状的分子标记，为种猪的选育提供新的参考标记；另一方面可揭示启动上区（CA）n微卫星影响Six1基因表达的分子机制，为阐明Six1基因影响猪肉质性状的遗传机制提供理论依据。

Six1, an important candidate gene affecting the porcine meat quality traits, has been shown to play an important role in the development of muscle and the transformation of muscle fibers. Moreover, microsatellite is an important regulatory element in genome, participating in a variety of biological life. Intriguingly, a (CA)n microsatellite is existed in the promoter of Six1 gene, and it is variable in Pietrain×Duroc×Landrace×Large White F2 resource population. However, the relationship between the variation of (CA)n microsatellite and meat quality traits, and the mechanisms of (CA)n microsatellite regulating the expression of Six1 gene are still unclear. In this project, the genetic diversity of the (CA)n microsatellite will be firstly detected in the Pietrain×Duroc×Landrace×Large White F2 resource population, and the association analysis will be performed between the polymorphisms of (CA)n microsatellite and the porcine meat quality traits. Furthermore, the effect of (CA)n microsatellite variation on the expression of Six1 will be verified in vivo and in vitro, and the regulatory mechanisms of (CA)n microsatellite affecting Six1 gene expression will be further explored. This study could develop the potential molecular marker affecting the porcine meat quality traits and provide the reference marker for pig breeding. On the other hand, this study could reveal the molecular mechanisms of (CA)n microsatellite affecting Six1 gene expression and provide theoretical basis for further elucidating the genetic mechanisms of Six1 affecting the porcine meat quality traits.