Fig. 5. Deletion of Hif1a in the lens specifically eliminates the hyaloid hypercellularity and aberrant vasculature of Cited2^-/- eyes. (A-D) H&E-stained serial paraffin sections of mouse embryo heads at 15.5 and 17.5 dpc revealed that at both stages, Cited2^-/-;Hif1a^flox/flox;Le-Cre^- eyes displayed lens stalk formation (arrowhead in A,C) and hyaloid hypercellularity with aberrant vasculature (arrow in A,C) (n=3). In Cited2^-/-;Hif1a^flox/flox;Le-Cre⁺ eyes (n=3), only the lens stalk (arrowhead in B,D), but not the hyaloid hypercellularity, was detected. Data shown are representative of three independent litters examined. (E) Le-Cre transgene-mediated deletion of Hif1a was assessed by real-time PCR analysis of Hif1a mRNA expression at 14.5 dpc, which revealed a 5-fold decrease in the Hif1a mRNA level in Cited2^-/-;Hif1a^flox/flox;Le-Cre⁺ lens (n=3) compared with the level detected in Cited2^-/-;Hif1a^flox/flox;Le-Cre^- lens (n=3). (F) As a consequence, Vegf mRNA expression decreased about 3-fold in Cited2^-/-;Hif1a^flox/flox;Le-Cre⁺ lens (n=3) compared with the level detected in Cited2^-/-;Hif1a^flox/flox;Le-Cre^- lens (n=3).