[Frontiers in Live Bone Imaging Researches. Novel fluorescent proteins for in vivo imaging].

Bone tissue is maintained by dynamic equilibrium of various types of cells. Thus, real time intravital imaging of movement and phenotypic changes of cells in the steady state and in pathophysiological state help us to understand molecular mechanism of bone tissue maintenance. Therefore, this review introduces Fucci-Tg mice for cell cycle imaging, caspase-3 indicator SCAT3.1 mice for cell death, and photoconvertible protein Kaede-Tg mice and cell-type specific KikGR mice for visualization of cell movement within intra-organ and between inter-organs.