A mouse model for beta cell-specific ablation of target gene(s) using the Cre-loxP system

The rat insulin promoter (RIP) has been used to drive the expression of Cre recombinase (Cre) specifically in beta cells. Transient transfection was p erformed in the mouse insulinoma cell line, NIT-I, and control cell lines. RT-PCR was performed using total RNA from pancreas and other tissues of RIP -Cre transgenic mice. In addition, the efficiency and specificity of RIP we re further analyzed by cross breeding the RIP-Cre transgenic mice with repo rter mice bearing a beta-actin-loxP-CAT-loxP-lacZ transgene. In these mice, lacZ is expressed only after excision of the floxed-CAT gene by Cre-mediat ed recombination. Here, we present the data for beta cell-specific expressi on of lacZ in bigenic mice, as proof of concept in a mouse model for target ing beta cell-specific gene(s). The RIP-Cre transgenic mice will be used as a potential tool for targeting the excision of beta cell-specific gene(s) to study their role in islet cell physiology. (C) 1998 Academic Press.