Fig. 3.

Variations in INSM1, Menin and Cyclin D1 expression with cell cycle and islet development. (A) Representative images of islets immunohistochemically stained for INSM1, Cyclin D1 and Menin in adult (45 weeks) and young (22 weeks) wild-type mice. (B) Graph showing Cyclin D1 and Menin expression in islets from young and adult mice, quantified from staining intensities by ImageJ. Values represent means of data obtained from three mice ± SD. Islets with a size above 50 μm (5 islets for each mouse) were used for the following calculation. (C, D) INSM1 protein was immunoprecipitated (IP) from non-proliferating (C) and proliferating (D) mouse β-cell lines (β-TC-06). Co-immunoprecipitation of cyclin D1 occurred only in non-proliferating β-TC-06 cells. Non-proliferative cells were synchronized in the G1 phase by double thymidine block. Normal IgG was used as control.