An enhancer trap is a transgenic construction for the identification of enhancers, produced by the fusing of two proteins, genes for which are inserted into the genome. The enhancer trap structure contains a mobile element (necessary for random insertion in the genome) usually some sort of P element (a promoter that must be sensitive to the enhancer) and a reporter gene. The reporter gene is necessary for identification of the spatial regulation by enhancers. The most common and basic enhancer traps are: P from the bacterium E. coli and P from yeast.
The enhancer trap also uses some sort of visible marker that allows the new insertions to be recognized such as the white gene, resulting in a red eye color in Drosophila or ampicillin resistance for E. coli.
There exists a large number of fly stocks containing GAL4 insertions and an equally large number of fly stocks containing an UAS DNA sequence followed by a gene of interest, which permits the expression of a large number of genes with different GAL4 "drivers". Rather than generating transgenic flies with the enhancer linked directly to the gene of interest (which takes about a year, if you are starting without the appropriate DNA construct), you simply mate (cross) one transgenic fly with another transgenic fly.
Famous quotes containing the word trap:
“We are not very much to blame for our bad marriages. We live amid hallucinations; and this especial trap is laid to trip our feet with, and all are tripped up first and last. But the mighty Mother who had been so sly with us, as if she felt that she owed us some indemnity, insinuates into the Pandora-box of marriage some deep and serious benefits, and some great joys.”
—Ralph Waldo Emerson (1803–1882)