Molecular machanism of the MFH-1 gene in, the aoortic arch formation, Skeletogenesis and kidney formation

在第一年，我们研究了MFH-1和Pax1基因在骨骼形成中的关系。我们得到的结果是MFH-1和Pax1在硬核组的腹侧和外侧区域表达，并且MFH-1的表达依赖于脊索。我们还研究了MFH-1/Pax1双敲除小鼠在硬化细胞中表现出比单敲除小鼠更严重的细胞增殖能力缺陷。这些结果表明，MFH-1和Pax1在脊椎骨形成过程中发挥协同作用。在第二年，我们研究了MFH-1和内皮素受体A （ETA）基因在主动脉弓形成中的关系。MFH-1和ETA在相似的区域和时间表达，且敲除小鼠均出现主动脉弓中断，这两种基因之间可能存在上下游关系。然而，基因敲除小鼠的原位杂交实验表明，MFH-1和ETA可能在主动脉弓形成中独立作用。去年，我们研究了mfh1 /ETA双敲除小鼠的表型。我们发现双基因敲除小鼠在胚胎期11.5天因心力衰竭死亡。在对MFH-1基因在骨分化中的作用的研究中，我们发现MFH-1基因在骨形成前表达强烈，在骨分化后表达减弱。接下来，我们确定MFH-1基因是否在植入含有骨形态发生蛋白（BMP）的小珠后被诱导。结果表明，MFH-1的表达在距离珠粒较远的小范围内增强。这些数据表明，BMP直接或间接地调控MFH-1基因在小鼠四肢骨形成中的作用。

In the first year we investigated the relationship between the MFH-1 and Pax1 genes in skeletogenesis. We obtained the results that MFH-1 and Pax1 were expressed in the ventral and lateral areas of sclerotome and that MFH-1 expression is dependent on the notochord. We also investigated that the MFH-1/Pax1 double knockout mice showed more severe defects in cell proliferative ability in the sclerotomal cells than either single knockout mouse did.These results showed that MFH-1 and Pax1 play a cooperative role in the sclerotome to make vertebraes. In the second year, we investigated the relationship between the MFH-1 and endothelin receptor A (ETA) genes in the aortic arch formation. The results that MFH-1 and ETA were expressed at the similar areas and at similar time and that both knockout mice showed interrupted aortic arch seem likely that there is an upstream-down stream relationship between these two genes. However, the in situ hybridization experiments using the knockout mice indicated that MFH-1 and ETA might act independently in the aortic arch formation. In the last year, we investigated the phenotypes of MFH 1/ETA double knockout mice. We found that the double knockout mice died at the embryonic day of 11.5 day due to heart failure. In the study on the role of MFH-1 gene in the bone differentiation, we found that the MFH-1 gene was expressed strongly just before the bone formation and its expression decreased after the bone was differentiated. Next, we determined whether the MFH-1 gene was induced in response to the implanted beads containing the bone morphogenetic protein (BMP) in the developing mouse limbs. The result showed that the MFH-1 expression was enhanced at a little remote site from the beads. The data together indicate that BMP regulates the MFH-1 gene directly or indirectly in the bone formation of mouse limbs.