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。多达50,000人中的一半 人类基因被认为是在大脑中表达的。同时对 人类基因组预计需要15-20年的时间，对一个大型的 克隆的数量可以很容易地提供关于基因的编码序列数据 在组织中表达。我们正在建立一个巨大的克隆图书馆， 人脑c DNA克隆的序列。一千个人脑序列 已在该项目的前3-4个月内完成。超过一半的人 分离到的基因是全新的基因，以前没有鉴定过或 克隆的。另外一个百分比是新的人类基因，已经 以前与其他物种隔绝的。蛋白质的计算机分析 一级和二级结构水平的序列是辅助克隆 身份证明。DNA和预测的蛋白质序列将被检查 保守的一级结构基序的存在及其与 以前测得的基因。进一步刻画潜在的 有趣的克隆将包括染色体定位，检查 组织分布表达，进化保守。这个 一个基础广泛的cdna序列文库的可用性也将 便于识别基因组序列中的编码区以及 为各个克隆项目提供起点。各种各样的 正在使用各种方法来选择特定于大脑的克隆，并消除 高度代表性的序列。

The goal of this project is to isolate, sequence, and characterize the genes expressed in human brain. As many as half of the more than 50,000 human genes are believed to be expressed in the brain. While sequencing the human genome is expected to take over 15-20 years, sequencing a large number of cDNA clones can readily provide coding sequence data on genes expressed in tissues. We are building a large library of clones and sequences of human brain cDNA clones. One thousand human brain sequences have been completed in the first 3-4 months of this project. Over half of the genes isolated are totally new genes, not previously identified or cloned. An additional percentage are new human genes, having been previously isolated from other species. Computer analysis of the protein sequences at the primary and secondary structural level is assisting clone identification. DNA and predicted protein sequences will be examined for the presence of conserved primary structure motifs and relationships to previously sequenced genes. Further characterization of potentially interesting clones will include chromosome localization, examination of tissue distribution of expression, and evolutionary conservation. The availability of a broad-based library of cDNA sequences will also facilitate identification of coding regions in genomic sequences as well as provide 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.