Figure 9. Effect of Gsx2 transduction on the proliferation of OB progenitor cells in vivo.

Retroviral particles expressing EGFP or Gsx2-EGFP were injected into the OB SEZ of P4 mice. OB sections obtained at P7 were immunostained with antibodies against GFP and the mitotic marker Phospho-Histone-H3 (PH-H3) (A, B) or the cell cycle marker Ki67 (C, D). The insets show high magnification images of the double-labeled cells indicated with arrowheads in the main images. Gsx2 overexpression caused a 45% reduction in the proportion of progenitors in mitosis (E) when compared with the controls, whereas the total number of cycling cells (F) was not significantly affected. Graphs in E and F represent the mean percentage ± s.e.m. (n = 5 animals per condition). *P<0.05 versus the values obtained from EGFP-infected cultures. Scale bar (shown in D) = 55.1 µm; insets = 31.9 µm.