Retnla^tm1.2Nair

A reporter marker cassette was inserted in antisense orientation downstream of exon 4, such that cre-mediated deletion of the targeted exon 2 to exon 4 will flip the reporter gene (tdTomato) into sense orientation leading to its expression. To enhance the stability of the reporter messenger and to increase the chance of having a bright signal, a WPRE sequence (woodchuck hepatitis virus post-transcriptional regulatory element) was added to the construct. The selection cassette was removed with a Flp recombinase strain. Cre-mediated recombination removed exons 2 through 4 and inverted the reporter cassette into sense orientation. (J:94077)