肠道是动物消化吸收养分的重要场所，也是机体重要的免疫屏障，维护肠道健康对于保障动物的正常生长发育具有极其重要的意义。小肽既是营养物质，又是生物活性分子，对机体具有营养和生理调节的双重功能。为了阐明小肽对肉仔鸡小肠上皮细胞（IEC）生长、增殖和凋亡的影响及其分子机理，本项目在前期研究基础上，以亮氨酰亮氨酸肽、甘氨酰甘氨酸肽和甘氨酰亮氨酸肽为实验材料，采用体外细胞培养、高通量测序、qRT-PCR和western blotting等技术，拟研究：小肽对IEC细胞生长、增殖和凋亡的影响；小肽对IEC基因表达的影响；小肽对IEC中差异信号蛋白表达的影响；小肽对体外IEC中雷帕霉素靶蛋白（TOR）及其上下游信号蛋白表达的影响。拟初步阐释小肽介导IEC信号传导通路，为完善“小肽营养理论”体系和建立小肽营养调控技术提供基础理论。

The intestine is not only a place for digestion and absorption of nutrients, but also an important immune barrier. Therefore, it is significant for livestock to keep intestine in health to achieve normal growth and development. The small peptides, the bioactive molecule as well as nutrients, have dual functions of nutritional and physiological regulation. Based on our previous works, the current project is conducted to clarify the effects of small peptides including L-Leu-L-Leu, Gly-Gly and Gly-L-Leu on growth, proliferation and apoptosis of intestinal epithelial cells（IEC）of broilers and molecular mechanism within above process using in vitro cell cultures, RNA-Seq, qRT-PCR and western blotting technologies. The project will investigate the effects of small peptides on growth, proliferation and apoptosis of broilers IEC, and the transcriptome and proteome of IEC, as well as abundance of proteins within TOR (Target of rampamycin) signaling pathway and in the upstream and downstream of TOR. These results will be helpful to elucidate signaling pathway mediated by small peptides in IEC of broilers, complete small peptide nutrition theory, and thus provide a basic guideline for small peptide nutritional regulation technology.