Medaka Osteoclast

During space flight bone mineral density is decreased by the influence of osteoclast activation which molecular mechanism is expectantly investigated. In the study of medaka bone development we investigated the system of vertebra formation and firstly identified the presence of osteoclasts in medaka. Moreover osteoclast rsorbing activity was affected by hypergravity indicating the possibility that we can investigate the effect of microgravity on osteoclasts in space. To find this effect we examine the alteration of osteoclast activity under microgravity with the histological analysis or the expression analysis by RNA in-situ hybridization. Furthermore since we have succeeded the establishment of the medaka osteoclast-specific transgenic lines we perform the in-vivo imaging analyses for gene expression and cell mobility. Finally to examine the gravity sensing system we employ tooth and bone as the high density organs which are highly sensitive to gravity and perform the histological analysis and the gene expression analysis of such gravity-sensitive tissues at surrounding pharyngeal teeth and supporting bone.

在航天飞行过程中，由于破骨细胞活性的影响，骨骼矿物质密度会降低，其分子机制有望得到深入研究。在斑马鱼骨骼发育的研究中，我们探讨了脊椎形成系统，并首次在斑马鱼中确定了破骨细胞的存在。此外，破骨细胞的吸收活性受到超重的影响，这表明我们可以探究微重力对航天环境中破骨细胞的影响。为了寻找这一效应，我们通过组织学分析或RNA原位杂交的表达分析，研究了微重力下破骨细胞活动的改变。此外，鉴于我们已经成功建立了斑马鱼破骨细胞特异性转基因系，我们进行了基因表达和细胞迁移的体内成像分析。最终，为了检验重力感知系统，我们以牙齿和骨骼作为对重力高度敏感的高密度器官，对邻近的咽齿和支持骨骼进行了组织学分析和基因表达分析。