Abstracts
1998 Digestive Disease Week

#1031

GENERATION OF A TISSUE SPECIFIC TRANSGENIC MOUSE MODEL USING CRE RECOMBINASE LINKED TO AN INSULIN PROMOTER. M.K. Ray, F.J. DeMayo, F.C. Brunicardi. Departments of Surgery and Cell Biology, Baylor College of Medicine, Houston, TX.

The rat insulin promoter has been characterized at Baylor College of Medicine enabling targeted gene expression in the beta cells. The purpose of this study was to express in vivo Cre recombinase specifically in beta cells of the mouse.

The 0.448kb rat insulin promoter (RIP) was isolated from RIP-pKS- plasmid (448 nucleotides of rat insulin promoter in Blue Script) by digesting with SalI and BamHI restriction enzymes. The Cre coding sequence having nuclear localization signal (NSL) and polyadenylation signal was isolated from plasmid, pOG231, by digesting with BglII and SalI. The isolated BglII/SalI fragment of Cre coding sequence was then ligated with the 0.448kb insulin promoter (Fig. 1). The RIP-Cre transgene was isolated from the vector sequence by digesting with NotI and SalI and transferred to the murine genome by microinjection of DNA into the pronucleus of one cell embryo. The one cell embryo was then transferred to a pseudopregnant mother and allowed to develop to full term. The offspring produced were screened for the presence of RIP-Cre transgene by the following method. DNA was isolated from the offsprings by tail digestion following a standard DNA isolation technique. The transgenic mice bearing the RIP-Cre transgene was identified by PCR (polymerase chain reaction) utilizing specific primers designed from the coding sequence of Cre and insulin promoter (Fig. 2). The presence of the transgene was further verified by Southern blot analvsis.

We conclude that a tissue specific transgenic mice model has been generated using Cre recombinase linked to RIP. This line of mice having RIP-Cre transgene will permit beta cell specific ablation of targeted genes.

Copyright 1996 - 1998, SSAT, Inc. Revised 29 June 1998.