| First Author | Tamarina NA | Year | 2014 |
| Journal | Islets | Volume | 6 |
| Issue | 1 | Pages | e27685 |
| PubMed ID | 25483876 | Mgi Jnum | J:232607 |
| Mgi Id | MGI:5779620 | Doi | 10.4161/isl.27685 |
| Citation | Tamarina NA, et al. (2014) Characterization of mice expressing Ins1 gene promoter driven CreERT recombinase for conditional gene deletion in pancreatic beta-cells. Islets 6(1):e27685 |
| abstractText | Gene manipulation using Cre-loxP recombination has proven to be an important approach for studying the impact of gene expression on pancreatic beta-cell biology. We report the generation of a transgenic mouse line that enables a highly specific system for conditional gene manipulation within beta-cells and achieve tissue specific and temporally regulated deletion of the Ctnnb1 (beta-catenin) gene in pancreatic beta-cells. cDNA encoding Cre recombinase fused to modified estrogen receptor (CreERT) under control of mouse insulin 1 gene promoter (Ins1) was used to construct the mouse line Tg(Ins1-Cre/ERT)1Lphi, also termed MIP1-CreERT. In a cross of MIP1-CreERT with a ROSA26/LacZ reporter strain, tamoxifen [Tmx] - dependent beta-galactosidase expression occurred within pancreatic beta-cells but not in other organ systems. Intraperitoneal glucose tolerance tests and glucose-stimulated changes in beta-cell cytoplasmic calcium concentration were not adversely affected in adult MIP1-CreERT. A mouse line with floxed Ctnnb1 gene (Ctnnb1f/f) was crossed with the MIP1-CreERT line to generate a mouse model for inducible beta-cell specific deletion of beta-catenin gene (Ctnnb1f/f:MIP1-CreERT). Ctnnb1f/f:MIP1-CreERT mice and Ctnnb1f/f littermate controls, were injected with Tmx as adults to knock down beta-catenin production in the majority of pancreatic beta-cells. These mice showed normal glucose tolerance, islet cyto-architecture and insulin secretion. A novel protein fraction of 50Kd, immunoreactive with anti-beta-catenin was observed in islet extracts from Ctnnb1f/f:MIP1-CreERT[Tmx] mice but not MIP1-CreERT-negative Ctnnb1f/f[Tmx] controls, indicating possible presence of a cryptic protein product of recombined Ctnnb1 gene. The MIP1-CreERT mouse line is a powerful tool for conditional manipulation of gene expression in beta-cells. |
