Fig. 5

Atrial Tg(fli1:nuEGFP) endocardial numbers were reduced while ventricular cardiomyocyte numbers were increased in sco^te382 mutant embryos. (A–F) Endocardial nuclei were labeled by Tg(fli1:nuEGFP) in wild-type (wt) (A–C) and sco^te382 mutant (D–F) embryos at 29hours 30minutes, 29hours 40minutes and 29hours 50minutes post fertilization. A representative set of time-lapse images showed one divided cell from 29hours 30minutes to 29hours 40minutes (1 in B), and three divided cells from 29hours 40minutes to 29hours 50minutes (2, 3 and 4 in C) in wild-type Tg(fli1:nuEGFP) embryos. Note that there were no divided cells from 29hours 30minutes to 29hours 50minutes in sco^te382 mutant embryos (D–F). (G) The endocardial proliferation rate (proliferating endocardium from 29 to 36hpf to the total endocardium at 29hpf) in sco^te382 was very low, compared with their siblings. n = 3; mean±s.e.m.; Student′s t-test. (H-J) The endocardium, labeled by Tg(fli1:nuEGFP), was divided into ventricular, AVC and atrial parts. Note fewer endocardial cells in the mutant AVC and atrium (I-J). (K-M) Myocardial nuclei were labeled by Tg(myl7:nuDsRed). Note more cardiomyocytes in the mutant ventricle (L-M). (J,M) n = 8–12; mean±s.e.m.; Student′s t-test. Scale bars: 30μm (A-F); 50μm (H-L).