ZFIN is incorporating published figure images and captions as part of an ongoing project. Figures from some publications have not yet been curated, or are not available for display because of copyright restrictions.

Analysis of zebrafish embryo phenotype following exposure to flavopiridol or morpholino injection. (A) Zebrafish embryos at 72 hpf continuously exposed to flavopiridol in the range 1–5µM from 24 hpf up to 120 hpf (at least n = 100 per group), or injected with morpholino 0.2ng/embryo (at least n = 100 per group). (B) Stacked column chart showing phenotypic traits observed following CDK9 inhibition. (C) Flavopiridol dose-dependent inhibition of CDK9 activity. Western blotting for Phospho Serine2 in the Carboxy-Terminal Domain (P-Ser2-CTD) of the RNA pol II. Serine 2 in this complex is phosphorylated by CDK9 when this is active. Tubulin was used as loading control.

Haematoxylin and eosin histological staining. Zebrafish embryos (Wik, wild type strain) injected with CDK9-targeting morpholino or exposed to Flavopiridol 3uM showed increased appearance of apoptotic/necrotic bodies (black and red arrowheads, respectively), particularly in the brain area, with underdeveloped forebrain and midbrain, compared to control (black arrow). Fb, forebrain; mb, midbrain; hb, hindbrain; Ys, yolk sac.

Effects of CDK9 inhibition on apoptotis. Lower panels – Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) immunostaining. Zebrafish embryos (Wik, wild type strain) at 72 hpf injected with CDK9-targeting morpholino or continuouly exposed to Flavopiridol 3μM showed significant increase in the appearance of apoptotic bodies (number of TUNEL positive nuclei) compared to control, counted in the trunk region and reported in the scatter graph. At least n = 12 embryo per group; data were statistically analyzed by student t-test; *** = ≤0.001.

BrdU immunostaining. Injection of CDK9-targeting morpholino or exposure to Flavopiridol reduced significantly the number of BrdU positive nuclei compared to controls. Brdu figures were counted in the tail region as shown in these images and reported in the scatter graph. At least n = 20 embryo per group; data were statistically analyzed by student t-test; ** = ≤0.01, *** = ≤0.001.

Immunostaining for CDK9 in whole larvae. (A) Confocal images of zebrafish embryo (Wik, wild type) 72 hpf control non-injected (above), injected with mismatch morpholino (middle) or CDK9-targeted morpholino (low) and immunostained with anti-CDK9 antibody, in red, and counterstained with DAPI. The staining shows diffuse presence of CDK9, in both nucleus and cytoplasm. The small yellow boxed area in a control non injected larva is shown at higher magnification in (B).