Peng, X., Dong, M., Ma, L., Jia, X.E., Mao, J., Jin, C., Chen, Y., Gao, L., Liu, X., Ma, K., Wang, L., Du, T., Jin, Y., Huang, Q., Li, K., Zon, L.I., Liu, T., Deng, M., Zhou, Y., Xi, X., Zhou, Y., Chen, S. (2015) A point mutation of zebrafish c-cbl gene in the ring finger domain produces a phenotype mimicking human myeloproliferative disease. Leukemia. 29(12):2355-65.
Controlled self-renewal and differentiation of hematopoietic stem/progenitor cells (HSPCs) are critical for vertebrate development and survival. These processes are tightly regulated by the transcription factors, signaling molecules, and epigenetic factors. Impaired regulations of their function could result in hematological malignancies. Using a large-scale zebrafish N-ethyl-N-nitrosourea (ENU) mutagenesis screening, we identified a line named LDD731, which presented significantly increased HSPCs in hematopoietic organs. Further analysis revealed that the erythoid/myeloid lineages in definitive hematopoiesis were increased while the primitive hematopoiesis was not affected. The homozygous mutation was lethal with a median survival time around 14-15 days post-fertilization. The causal mutation was located by positional cloning in the c-cbl gene, of which the human ortholog, c-CBL, is found frequently mutated in myeloproliferative neoplasms (MPN) or acute leukemia. Sequence analysis showed the mutation in LDD731 caused a histidine-to-tyrosine substitution of the amino acid (aa) codon 382 within the RING finger domain of c-Cbl. Moreover, the myeloproliferative phenotype in zebrafish seemed dependent on the Flt3 (fms-like tyrosine kinase 3) signaling, consistent with that observed in both mice and humans. Our study may shed new lights on the pathogenesis of MPN and provide a useful in vivo vertebrate model for drug screenings for this syndrome.