Figure 3.

Conditional Ablation of Dicer in Mature Olfactory Neurons and Olfactory Progenitors

(A) Schematic diagram of the Dicer conditional targeting construct used in this study (Harfe et al., 2005).

(B) Cross of OMP-Cre and Dicer^loxP/loxP transgenic lines. miR-200b and OMP expression overlaps in mature neurons (left and center panels). Mature miR-200b expression is abolished in OMP-expressing cells of OMP-Cre; Dicer^loxP/loxP mice but remains in OMP-negative, immature neurons and progenitor cells located in the basal MOE (right panel). Broken black line indicates the basal lamina of the MOE. Northern blot analysis confirms the reduction in miR-200b expression (right blot).

(C) Cross of Foxg1-Cre and Dicer^loxP/loxP transgenic lines. Tissues derived from the olfactory placodes of Foxg1-Cre^+/−; Dicer^loxP/loxP tissues were analyzed for expression of mature miR-200a and miR-449 expression. Expression of Foxg1 in adjacent sections was used to demonstrate that MOE and respiratory epithelial tissue is still present in these mutants.