人牙乳头细胞Smad1基因MH2结构域的cDNA的分子克隆

目的：从人牙乳头细胞内克隆骨形成蛋白（BMP）细胞内信号转导基因Smad1的功能性结构域－－MH2结构域。方法：原代培养人牙乳头细胞，从培养的细胞中提取总DNA，逆转录合成cDNA第1条链；设计上下游引物，进行RT－PCR，扩增Smad1基因MH2结构域的基因片段；将所获得的基因片段定向插入PUC19载体；转化大肠杆菌JM109，挑选阳性克隆，鉴定后进行序列测定。结果：获得的Smad1 MH2结构域的cDAN片段大小为444bp，并且成功构建PUC19／MH2重组质粒。结论：人牙乳头细胞内存在Smad1信号转导途径，BMP调控人牙乳头细胞分化可能是通过Smad1信号途径实现的。

cDNA cloning and sequencing of MH2 domain of Smadl from human dental papilla cells

Objective:To clone and sequence cDNA of MH2 domain of Smad1 gene from human dental papilla cells. Methods:Total RNA was isolated from primarily cultured human dental papilla cells and reversely transcribed into single stranded cDNA.The desired DNA product was obtained by PCR with two gene specific primers.The segment was inserted into PUC19 vector and the plasmid was transformed into E.coli JM109.The double stranded cDNA of positive clone was sequenced.Results:The sequence of MHz domain of Smad1 cloned from human dental papilla cells was consistent with that reported by Hoodless et al. Conclusion:Smad1 exists in human dental papilla cells,BMP signaling may be mediated by smad1 in human dental papilla cells.