髓质骨是雌禽所特有的结构，其主要功能是为蛋壳钙化提供钙源。新型钙离子通道TRPV5和TRPV6是成骨细胞膜和破骨细胞膜上调控钙离子转运的重要通道，但该蛋白在维持髓质骨形成与重建的作用途径和分子机制仍不详。本项目通过构建TRPV5/6 siRNA重组表达质粒，研究TRPV5/6对成骨细胞和破骨细胞、发育、增殖、分化及凋亡的影响，探讨TRPV5/6对OPG、RANKL、MAPKs及sSmads等信号系统基因表达的调控作用。另外，通过体内试验，研究TRPV5/6 siRNA质粒对未性成熟和高产蛋鸡髓质骨OPG、RANKL、MAPKs及Smads等信号通路基因的表达、骨代谢标志物、骨形态计量学及蛋鸡生产性能的影响等，揭示蛋鸡髓质骨形成TRPV5/6钙离子通道及其调控信号传导系统的作用途径及分子机理，为蛋鸡骨质疏松症症病因学、病理学等研究提供理论依据。

The unique medullary bone is formed in the marrow cavities of the long bones of mature female birds, and it serves as a labile source of Ca2+ for shell calcification. The transient receptor potential vanilloid receptor 5，6 (TRPV5, TRPV6) are considered to facilitate the entry of Ca2+ into the epithelial cells of osteoblast (OB) and osteoclast (OC) in bone, but the specific role and form mechanism of the medullary bone has not yet been studied in laying hen. Effects of TRPV5/6 on the growth, development, proliferation, differentiation and apoptosis of osteoblasts and osteoclsts and regulation of TRPV5/6 on genetic expression of the signaling system of OPG、RANKL、MAPK and sSmad, and so on were in vitro investigated with construction of the recombined plasmid TRPV5/6 small interfering RNA（siRNA）in this project. In addition, The gene silence effect of TRPV5/6 siRNA on the expression of genes including TRPV5/6, the signal pathway of OPG, RANKL, MAPKs and sSmads, bone metabolic markers, morphometry of medullary bone, and laying performance is determined in vivo. The objective of this study is able to reveal the action approach and molecular mechanism of TRPV5/6 calcium channel and their regulation of signal transduction systems on the medullary bone formation. Moreover, this project may play an important role in providing the theoretical evidence for etiology and pathology of calcium metabolism disorders of osteoporosis and joint diseases in layers.