Expressed Sequence Tags database

dbEST is a division of GenBank that contains sequence data and other information on "single-pass" cDNA sequences, or "Expressed Sequence Tags", from a number of organisms. Expressed Sequence Tags (ESTs) are short (usually about 300-500 bp), single-pass sequence reads from mRNA (cDNA). Typically they are produced in large batches. They represent a snapshot of genes expressed in a given tissue and/or at a given developmental stage. They are tags (some coding, others not) of expression for a given cDNA library. Most EST projects develop large numbers of sequences. These are commonly submitted to GenBank and dbEST as batches of dozens to thousands of entries, with a great deal of redundancy in the citation, submitter and library information. To improve the efficiency of the submission process for this type of data, we have designed a special streamlined submission process and data format. dbEST also includes sequences that are longer than the traditional ESTs, or are produced as single sequences or in small batches. Among these sequences are products of differential display experiments and RACE experiments. The thing that these sequences have in common with traditional ESTs, regardless of length, quality, or quantity, is that there is little information that can be annotated in the record. If a sequence is later characterized and annotated with biological features such as a coding region, 5'UTR, or 3'UTR, it should be submitted through the regular GenBank submissions procedure (via BankIt or Sequin), even if part of the sequence is already in dbEST. dbEST is reserved for single-pass reads. Assembled sequences should not be submitted to dbEST. GenBank will accept assembled EST submissions for the forthcoming TSA (Transcriptome Shotgun Assembly) division. The individual reads which make up the assembly should be submitted to dbEST, the Trace archive or the Short Read Archive (SRA) prior to the submission of the assemblies.

dbEST是GenBank的一个分支，其中包含多种生物体的“单次通过”cDNA序列，或称为“表达序列标签”（EST）。表达序列标签（EST）是由mRNA（cDNA）提取的短序列（通常约为300-500碱基对），为单次序列读取。它们通常以大批量生产。这些标签代表了在特定组织或发育阶段表达的基因的快照。它们是针对特定cDNA库的表达标签（部分具有编码功能，部分则否）。大多数EST项目都开发了大量的序列。这些序列通常以数十到数千条条目的批次提交给GenBank和dbEST，其中在引文、提交者和库信息方面存在大量的冗余。为了提高此类数据的提交效率，我们设计了一种特殊的简化提交流程和数据格式。dbEST还包括比传统EST更长的序列，或者以单个序列或小批量生产的序列。这些序列中包括差异显示实验和RACE实验的产物。这些序列与传统EST的共同点，无论其长度、质量或数量如何，是记录中可注释的信息非常有限。如果一个序列后来被表征并带有生物特征，如编码区、5'UTR或3'UTR，即使序列的部分已存在于dbEST中，也应通过常规的GenBank提交程序（通过BankIt或Sequin）提交。dbEST仅用于单次读取。不应将组装序列提交给dbEST。GenBank将接受即将推出的TSA（转录组鸟枪法组装）分区的组装EST提交。在提交组装之前，应将组成组装的个别读取提交给dbEST、Trace归档或Short Read Archive（SRA）。