As the shRNA plasmids also coded for a green fluorescent protein, we used CellTracker RedTM to label the NBFs. RNAi knockdown of cadherin-23 significantly affected the ability of MCF-7 cells to participate in both homotypic and heterotypic adhesion, consistent with the results obtained from the antibody inhibition experiments. Runx2b, a maternal and zygotic mediator, has been reported to induce the Timosaponin-BII expression of ventral gene such as ved, vent and vox in the earliest embryo of zebrafish; however the upstream molecule regulating the expression of runx2b has not been discovered. Knockdown of twist1a and twist1b suggesting the early involvement of twist in controlling the dorsoventral patterning. The phenotypes of the knockdown of twist1a and twist1b include abnormalities in eyes, fusion of fore/midbrain and hindbrain, notochord, trunk, and other skeleton deformity, which are normally observed in the ventralized embryos induced by mutation or knockdown of dorsalspecific genes or overexpression of ventral-specific genes. Together with Runx2, a number of molecules involved in dorsoventral patterning also participate in bone Cantharidin formation, transforming growth factor-b and fibroblast growth factors. Runx1 and Runx3 also interact with similar molecules in haematopoiesis and gastric epithelial maintenance, respectively. Whether the expressions of these genes are also regulated by twist has not been clarified and necessitates future investigation. Future exploration of the twist signaling pathways may help in developing strategies to control skeleton development and dorsoventral patterning through suppressing runx2b. In conclusion, these data provide convincing evidences for the important roles of Twist in controlling dorsoventral patterning, skeleton development and bone mineralization. Further exploration of the mechanism involved in Twist-mediate regulation of skeleton development and regeneration may provide new strategies for treating these diseases. Mammalian cell division is controlled by the expression of cyclins and activation of their associated cyclin dependent kinases. While the CDK components are generally expressed ubiquitously during the cell cycle, expression of cyclins accumulate periodically during distinct phases of the cell cycle. In each phase, binding of cyclins with their corresponding CDK forms an active cyclin complex.