Abstract

Myostatin (MSTN) gene, also known as growth and differentiation factor 8 (GDF8) gene, is a negative regulator of skeletal muscle growth and development, especially the number, size and type of muscle fibers. Its mutations contribute to the double-muscling (DBM) phenomenon which significantly increases the muscle mass. Hence, variations within MSTN/GDF8 gene receive so much attention in several kinds of species such as bovines, poultries, goats, sheep, horses. A 5-base pairs (bp) indel in the 5’ untranslated region (5’UTR) of goat MSTN/GDF8 was verified to be significantly associated with growth traits except Inner Mongolia White Cashmere (IMWC) goats. Given that almost all sample sizes were below 150, we enlarged sample sizes to more than 500 to uncover the association between the 5-bp indel and growth traits in IMWC goats. Only two genotypes (deletion/deletion (DD) and insertion/deletion (ID)) were found, and DD genotypes were dominant genotypes. The detected locus displayed low genetic diversity (PIC = 0.090). Interestingly, the association analyses revealed that the 5-bp indel had a significant effect on the chest depth (p = 0.003), and DD genotypes were dominant genotypes. Hinted that the 5-bp indel could act as an effective marker in molecular marker-assisted selection (MAS) processes for selection of excellent goat individuals.

摘要

肌生长抑制素（MSTN）基因，又称生长分化因子8（GDF8）基因，是骨骼肌生长发育的负调节因子，尤其是肌纤维的数量、大小和类型。它的突变导致双肌肉 (DBM) 现象，显着增加肌肉质量。因此，MSTN / GDF8基因内的变异在牛、家禽、山羊、绵羊、马等几种物种中受到了如此多的关注。山羊MSTN / GDF8的 5' 非翻译区 (5'UTR) 中的 5 碱基对 (bp) 插入缺失被证实与除内蒙古白绒（IMWC）山羊以外的生长性状显着相关。鉴于几乎所有样本量都低于 150，我们将样本量扩大到 500 以上，以揭示 5-bp 插入缺失与 IMWC 山羊的生长性状之间的关联。仅发现两种基因型（缺失/缺失（DD）和插入/缺失（ID）），DD基因型为显性基因型。检测到的基因座显示出低遗传多样性（PIC = 0.090）。有趣的是，关联分析显示5-bp indel对胸深有显着影响（p  = 0.003），DD基因型是优势基因型。表明 5-bp indel 可以作为分子标记辅助选择 (MAS) 过程中的有效标记，用于选择优秀山羊个体。