*Kian-Chung Lee1, Walter LP Goh1, , Meihui Xu1, Nelly Kua1, , Declan Lunny2, Julin S Wong1, David Coomber1, Borivoj Vojtesek1, E Birgitte Lane2 and David P Lane1*
1Control of p53 Pathway Laboratory, Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673
2Epithelial Biology Programme, Institute of Medical Biology, 61 Biopolis Drive, Proteos, Singapore 138673
The zebrafish has many advantages as a vertebrate model organism and has been extensively used in studies of development. Its potential as a model in which to study tumour suppressor and oncogene function is now being realized. Whilst in situ hybridization of mRNA has been well developed in this species to study gene expression, antibody probes are in short supply. We have therefore generated a panel of anti-zebrafish p53 monoclonal antibodies and used these to study the p53 response in zebrafish embryos. By immunohistochemistry, we show that exposure of zebrafish embryos to p53-activating agents such as R-roscovitine and γ irradiation results in the accumulation of p53 protein in the gut epithelium, liver and pancreas. A combination of R-roscovitine and γ irradiation results in massive p53 induction, not only in the pharyngeal arches, gut region and liver but also in brain tissues. Induction of apoptosis and expression of p53 response genes is seen in regions which correspond to sites of p53 protein accumulation. In contrast, although zebrafish tp53M214K mutant embryos showed a similar accumulation of p53 protein, a complete lack of a downstream p53-dependent response was observed. In this system the p53 gene is identified as a p53 responsive gene itself. Our results demonstrate that zebrafish p53 protein can readily be induced in embryos and detected using these new antibody tools, which will increase the usefulness of zebrafish as a model in compound-based screening for novel drugs in cancer research.
Keywords: zebrafish, p53, monoclonal antibody, immunohistochemistry, p53-activating agents
Published in Oncogene advance online publication, August 6, 2007; doi:10.1038/sj.onc.1210695