摘要：Inhibitory G proteins (G
i proteins) are highly homologous but play distinct biological roles. However, their isoform-specific detection remains challenging. To facilitate the analysis of Gα
i3 expression, we generated a
Gnai3- iresGFP reporter mouse line. An internal ribosomal entry site (IRES) was inserted behind the stop-codon of the
Gnai3 gene to initiate simultaneous translation of the GFP cDNA together with Gα
i3. The expression of GFP was confirmed in spleen and thymus tissue by immunoblot analysis. Importantly, the GFP knock-in (ki) did not alter Gα
i3 expression levels in all organs tested including spleen and thymus compared to wild-type littermates. Flow cytometry of thymocytes, splenic and blood cell suspensions revealed significantly higher GFP fluorescence intensities in homozygous ki/ki animals compared to heterozygous mice (+/ki). Using cell-type specific surface markers GFP fluorescence was assigned to B cells, T cells, macrophages and granulocytes from both splenic and blood cells and additionally blood-derived platelets. Moreover, immunofluorescent staining of the inner ear from knock-in mice unraveled GFP expression in sensory and non-sensory cell types, with highest levels in Deiter’s cells and in the first row of Hensen’s cells in the organ of Corti, indicating a novel site for Gα
i3 expression. In summary, the
Gnai3- iresGFP reporter mouse represents an ideal tool for precise analyses of Gα
i3 expression patterns and sites.
