Fig. 5.

Myc is required for cell proliferation and apoptosis in hyaloid VECs. Flat-mounted P8 hyaloid vessels from VEC conditional Myc heterozygote and homozygote mice as labeled. There is dramatic hyaloid persistence in homozygous Myc^flox/flox; Pdgfb-icreERT2 mice (C) and mild persistence in heterozygous Myc (Myc^flox/+; Pdgfb-icreERT2) mice (B) compared with wild-type littermate controls (Myc^+/+; Pdgfb-icreERT2) (A). (D) Quantification of hyaloid vessel numbers in mice of the labeled genotypes. (E,F) Flat-mounted hyaloid vessels from P5 animals were labeled for BrdU (n≥6) (E,F) or TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) (H,I) along with Hoechst. Quantification of BrdU-positive nuclei (G) and TUNEL-positive apoptotic vascular segments (J). Data are mean±s.e.m. Statistical significance was tested using Student's t-test, n≥4. (K) Immunoblot showing active β-catenin (CTNNB1), MYC and β-tubulin (TUBB) in Lrp5/6 control and CKO BMVECs stimulated with Wnt3a.