Fig. 8. Analysis of growth plates from control, Hif1a null and Hif1a/Vhlh null mice. (A-C,H-J) Hematoxylin and Eosin staining of histological sections of control (A,H), Hif1a null (B,I) and Hif1a/Vhlh null mice (C,J), at E14.5 (A-C) and birth (H-J). (E-G) Evidence for increased cell proliferation rates in Hif1a null and Hif1a/Vhlhnull chondrocytes. Detection of BrdU-labeled chondrocytes in histological sections of E14.5 control (E), Hif1a null (F) and Hif1a/Vhlh null (G) proximal tibia growth plates. (D) Percentage of BrdU-labeled cells; bars represent mean percentages (±s.d.) of BrdU-labeled chondrocytes in Hif1a null, Hif1a/Vhlh null and wild-type (WT) growth plates at E14.5, separated into proliferating zone (PZ) and resting zone (RZ). Statistical differences in each zone were identified using the unpaired t-test. ^**P<0.01.