Molecular Biology of the Gene Expression of Hard Tissue Forming Cells

(1)牛釉原蛋白基因在X染色体和Y染色体上均有表达。牛釉原蛋白基因定位于X和Y染色体。研究牛釉原蛋白Y染色体基因在转录水平的表达。从雄性和雌性胎牛肝脏和牙胚中分离染色体DNA、信使RNA和釉质蛋白。已知Y染色体釉原蛋白基因相对于X染色体釉原蛋白缺失了21个氨基酸的结构域。雄性mRNA的RT-PCR产物在琼脂糖凝胶上有两条带。而女性则只有一条带，表明Y染色体釉原蛋白基因具有转录活性。结果表明，牛Y染色体上的釉原蛋白基因具有活性，能产生雄性釉原蛋白。(2)原位杂交技术观察牙移动过程中牙槽骨改建 ...更多信息 zation. - I型胶原和骨唾液蛋白mRNA的表达-研究了伴随牙齿移动的牙槽骨中I型胶原和骨唾液蛋白（BSP）mRNA的表达。在适当的运动天数后，将组织学成分脱钙并切成石蜡切片。用原位杂交方法检测mRNA的表达。在生理性牙齿移动的样本中，在成骨细胞中观察到两种mRNA的高水平表达，沿着矿化和相邻的根间隔膜（IRS）中的骨细胞。在实验性牙齿移动的标本中，IRS张力侧成骨细胞中检测到高水平的表达，这些结果表明，BSP基因的表达以及胶原蛋白的表达不仅与生理性骨重建中的矿化有关，而且与骨重建中的骨代谢有关。成骨细胞在正畸力的作用下被激活。少

(1) The Bovine Amelogenin Genes Are Expressed from Both the X and the Y Chromosomes.The bovine amelogenin genes are localized to X and Y chromosomes. To investigate the expression of bovine amelogenin Y-chromosomal gene at the transcription levels., chromosomal DNAs, messenger RNAs and enamel proteins were isolated from male and female fetal bovine liver and tooth germ. It was known that 21-amino acid domain was deleted in the Y-chromosomal amelogenin gene, relative to the X-derived amelogenin. The RT-PCR products from male mRNA had two bands on agarose gel. while those from female had one band, indicating Y-chromosomal amelogenin gene was transcriptionally active. Both cell-free translation products and enamel proteins from male had more complex spots than those from female.These results indicate that the bovine amelogenin gene on Y-chromosome is active and produces male speciffic amelogenin.(2) Observation of Alveolar Bone Remodeling Accompanied with Tooth Movement by in situ hybridi … More zation. -Expression of Type I Collagen and Bone Sialoprotein mRNAs-Expression of type I collagen and bone sialoprotein (BSP) mRNA in the alveolar bone accompanied with tooth movement was investigated. After the proper number of days of movement, histological speciments were decalcified and sliced into paraffin sections. The expression of mRNAs was examined by the in situ hybridization method. In the samples of physiological toothmovement, a high level of expression in both mRNAs was observed in osteoblasts along the mineralization from and adjacent osteocytes in the interradicular septum (IRS). In contrast, a low level of mRNA expression was observed on the opposite side of the IRS.In the specimens of experimental tooth movement, a high level of experssion was detected in the osteoblasts on the tension side of IRS,but negligible reaction in those on the compression side.These results suggest that BSP gene experssion as well as that of collagen are related not only to mineralization in physiological bone remodeling but also to the process by activated osteoblasts induced by orthodontic force. Less