Matsuki Y, Nakashima M, Amizuka N, Warshawsky H, Goltzman D, Yamada K M, Yamada Y
Laboratory of Developmental Biology, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892.
J Dent Res. 1995 Jan;74(1):307-12. doi: 10.1177/00220345950740010401.
The formation of tooth organs is regulated by a series of developmental programs. We have initiated a genome project with the ultimate goal of identifying novel genes important for tooth development. As an initial approach, we constructed a unidirectional cDNA library from the non-calcified portion of incisors of 3- to 4-week-old rats, sequenced cDNA clones, and classified their sequences by homology search through the GenBank data base and the PIR protein data base. Here, we report partial DNA sequences obtained by automated DNA sequencing on 400 cDNA clones randomly selected from the library. Of the sequences determined, 51% represented sequences of new genes that were not related to any previously reported gene. Twenty-six percent of the clones strongly matched genes and proteins in the data bases, including amelogenin, alpha 1(I) and alpha 2(I) collagen chains, osteonectin, and decorin. Nine percent of clones revealed partial sequence homology to known genes such as transcription factors and cell surface receptors. A significant number of the previously identified genes were expressed redundantly and were found to encode extracellular matrix proteins. Identification and cataloging of cDNA clones in these tissues are the first step toward identification of markers expressed in a tissue- or stage-specific manner, as well as the genetic linkage study of tooth anomalies. Further characterization of the clones described in this paper should lead to the discovery of novel genes important for tooth development.
牙齿器官的形成受一系列发育程序调控。我们已启动一个基因组项目，其最终目标是鉴定对牙齿发育重要的新基因。作为初步方法，我们从3至4周龄大鼠切牙的非钙化部分构建了一个单向cDNA文库，对cDNA克隆进行测序，并通过GenBank数据库和PIR蛋白质数据库的同源性搜索对其序列进行分类。在此，我们报告从该文库中随机选择的400个cDNA克隆通过自动DNA测序获得的部分DNA序列。在已确定的序列中，51%代表与任何先前报道的基因均无关联的新基因序列。26%的克隆与数据库中的基因和蛋白质高度匹配，包括釉原蛋白、α1(I)和α2(I)胶原链、骨连接蛋白和核心蛋白聚糖。9%的克隆显示出与已知基因如转录因子和细胞表面受体的部分序列同源性。大量先前鉴定的基因存在冗余表达，且发现它们编码细胞外基质蛋白。对这些组织中的cDNA克隆进行鉴定和编目是鉴定以组织或阶段特异性方式表达的标志物以及牙齿异常的遗传连锁研究的第一步。对本文所述克隆的进一步表征应能发现对牙齿发育重要的新基因。
