IGF-1c.258A>G同义突变在小型猪发育性骨生长中的作用及机制

阐明小型猪体型矮小的机制是其开发利用的首要前提，但目前多挖掘功能基因变异，对变异的影响及生化机制研究不深。IGF-1作为对动物发育性骨生长起决定性作用的因子在猪体型形成中起关键作用，本课题组筛选发现IGF-1编码区在不同体型猪中仅存在1处同义突变c.258A>G，并证实其能够影响蛋白质生物合成。鉴于目前鲜有报道对特定同义突变通过基因编辑进行深入解析，本项目拟率先利用新报道的ABE系统在细胞和动物上实现A/G编辑，明确IGF-1c.258A>G对基因表达和分泌的影响，从mRNA及蛋白质稳定性、剪接机制、蛋白质构象及折叠速率、复合物动态结合等角度深入剖析其影响机制；解析其对成/破骨细胞功能、骨生长相关因子及信号通路的影响；最终观察其对发育性骨生长及动物体型的作用。综上，本项目在分子、细胞和动物水平深入解析IGF-1c.258A>G同义突变在小型猪体型矮小中的作用，为小型猪的应用提供基础数据。

Elucidating the mechanism of diminutive size of miniature pigs is the primary prerequisite for their development and utilization. IGF-1 as an essential factor that plays a decisive role in the developmental growth and metabolism of mammalian bone and in the formation of pig body shape likewise. In our previous studies, only one synonymous mutation c.258A>G of IGF-1 gene was found to be significantly associated with pig body size and also among mammalian species, which has been shown to affect protein biosynthesis. Since there are few details of specific synonymous mutations through gene editing have been reported, in this study, ABE system will be used to achieve A/G editing in cells and animals to clarify the effect of IGF-1 c.258A>G on gene expression and secretion. Furthermore, the mechanism of mRNA and protein stability, splicing mechanism, protein conformation and folding rate, complex dynamic binding and other aspects will be analyzed and the effects on osteoclasts/osteoblast function, bone growth-related factors and signaling pathways will be elucidated. Finally, the functional impact of the synonymous mutation on developmental bone growth and animal body size will be observed. In summary, this study will reveal the role of IGF-1 synonymous mutation c.258A>G in the developmental bone growth of miniature pigs from the novel perspectives of molecular (structural), cellular and animal levels and provide basic data for miniature pig applications.