HUMAN BRAIN CDNA PROJECT

这个项目的目标是分离、测序和鉴定 在人脑中表达的基因。近5万人中多达一半的人 人类基因被认为是在大脑中表达的。在进行排序时 人类遗传物质的一半预计需要十年以上的时间，而且 所得到的基因组序列中的编码区可能不清楚 有识之士，对大量的cdna克隆进行测序可以很容易地提供 对序列数据进行编码。我们正在建立一个庞大的序列文库 人脑cdna克隆。基础广泛的图书馆的可用性 CDNA序列将有助于识别编码区 基因组序列以及为个体提供一个起点 克隆项目。正在使用各种方法来选择 大脑特有的克隆，并消除高度代表性的序列。 超过8000个人类大脑基因已经被识别出来 方法。DNA和预测的蛋白质序列的计算机分析 执行以搜索是否存在保守的一级结构 基序和与以前测序的基因的关系。它被发现了 超过一半的序列代表了没有被检测到的新基因 与之前测序的基因相似。额外的百分比 代表已在其他基因中测序的人类同源基因 有机体。进一步刻画了几个有趣的克隆 神经发育中的潜在角色目前正在进行中，并将 包括染色体定位、组织分布检查 表达、功能分析和进化守恒。

The goal of this project is to isolate, sequence, and characterize the genes expressed in human brain. As many as half of the almost 50,000 human genes are believed to be expressed in the brain. While sequencing half of the human genetic material is expected to take over a decade, and coding regions in the resultant genomic sequence may not be clearly discerned, sequencing a large number of cDNA clones can readily provide coding sequence data. We are building a large library of sequences of human brain cDNA clones. The availability of a broad-based library of cDNA sequences will facilitate identification of coding regions in genomic sequences as well as providing a starting point for individual cloning projects. A variety of approaches are being used to select brain-specific clones and to eliminate highly represented sequences. Over eight thousand human brain genes have been identified by this method. Computer analysis of DNA and predicted protein sequences were performed to search for the presence of conserved primary structure motifs and relationships to previously sequenced genes. It was found that over half of the sequences represented new genes with no detectable similarity to previously sequenced genes. An additional percentage represent the human homolog of genes that have been sequenced in other organisms. Further characterization of several interesting clones with potential roles in neural development is currently in progress and will include chromosome localization, examination of tissue distribution of expression, functional analysis, and evolutionary conservation.