Gene-trap mutagenesis: past, present and beyond

Abstract

Although at least 35,000 human genes have been sequenced and mapped, adequate expression or functional information is available for only approximately 15% of them. Gene-trap mutagenesis is a technique that randomly generates loss-of-function mutations and reports the expression of many mouse genes. At present, several large-scale, gene-trap screens are being carried out with various new vectors, which aim to generate a public resource of mutagenized embryonic stem (ES) cells. This resource now includes more than 8,000 mutagenized ES-cell lines, which are freely available, making it an appropriate time to evaluate the recent advances in this area of genomic technology and the technical hurdles it has yet to overcome.

Identification and validation of PDGF transcriptional targets by microarray-coupled gene-trap mutagenesis

“…Because large-scale phenotypedriven gene-trap screens are prohibitively laborious and costly, preselection of gene-trap events of interest is highly desirable. A number of expression-driven screening strategies have been designed to search for genes that are restricted to specific lineages, are responsive to external stimuli or encode secreted proteins 29 . But all these screens are confined to ES cells or their differentiated derivatives and rely on reporter expression.…”

A Mutation inAf4Is Predicted to Cause Cerebellar Ataxia and Cataracts in the Robotic Mouse

“…Of the possible routes to mutagenizing the mouse genome, gene-trapping vectors and chemical mutagenesis are being used on a large scale to provide a significant number of new mutants for gene function analysis (Hrabe de Angelis et al, 2000;Nolan et al, 2000;Stanford et al, 2001). An advantage of phenotype-based mutagenesis is that no assumptions are made about the possible function of the genes involved; instead we rely on sensitive phenotype analysis of individual animals.…”

Effective Expression-Independent Gene Trapping and Mutagenesis Mediated by Sleeping Beauty Transposon

“…A conventional gene-trap vector consists of a promoterless marker/reporter gene flanked by an upstream splice acceptor and a downstream poly(A) signal (Gossler et al, 1989;Stanford et al, 2001). …”

“…The nuclear premRNA is then spliced to form a fusion transcript with the trapped exon immediately upstream of the insertion site. Since the processed fusion transcript encodes a truncated, often nonfunctional version of endogenous protein and the marker/ reporter, gene trapping is employed to elucidate gene functions by disrupting expression of trapped genes across a target genome (Stanford et al, 2001). During the past two decades, a number of gene-trap vectors have been successfully used for insertional mutagenesis and high-throughput screening of mutations in genes of embryonic stem cells (ESCs).…”