Using Lab On-line to Clone and Identify the Esophageal Cancer Related Gene 4

Using Internet as platform, databases as materials and software as tools to assemble a lab on-line is revolutionizing in bioscience research. The major works of lab on-line are cloning, identification, localization of genes, and the structural and functional analysis of proteins. In this report, the esophageal cancer related gene 4(ECRG-4)(accession number AF325503) was successfully isolated. The 97 bp ECRG-4 EST was initiallyusedto fish the human EST databases. Five pieces of ESTs showed strong homology to it, and they were assembled to one 772 bp cDNA sequence by DNASTAR software. Then the 447 bp full open reading frame of ECRG-4 was determined by ORF FINDER to encode 148 amino acids. Sequence of ECRG-4 did not reveal remarkable similarity to the known sequences in a homology analysis with the public database of GenBank, showing that it is a new gene. Homology analysis of protein coding by ECRG-4 showed a 31% homology with mouse IgG V region. ECRG-4 gene is expressed in normal esophagus, bladder and brain tissues, but its expression was significantly down-regulated in prostate tumors and tumor cell lines. ECRG-4 gene was located in 2q14.1--4.3 by HTGS and STS, and was conformed by radiation hybrid (RH) method. We propose that this purely lab on-line cloning approach can be used by modestly sized laboratories to rapidly and accurately characterize human genes without wasting too much money and time.