The Identification and Localization of the Abelson Oncoprotein in Zebrafish, (Danio rerio)

The ubiquitously expressed Abelson oncoprotein (Abl) has multiple molecular functions, which affect homeostasis and cytoskeletal structuring of the cell. Mutation of the Abl gene is the causal event in several types of leukemia and is linked to the progression of certain lung and breast cancers. Despite extensive literature documenting the protein’s function in humans and the recent explosion of cancer research using zebrafish, no research to date has investigated the existence of an Abl ortholog in Danio rerio. We have sequenced a cDNA clone from D. rerio that demonstrates high identity to other vertebrate Abl proteins. In addition, we have investigated expression of the abl gene and abl protein during early embryonic development by in situ hybridization and immunohistochemistry. Expression of the gene and protein begins at 12 hours post fertilization and correlates to areas of nervous system development within the head and hematopoietic differentiation within the posterior blood island. These results suggest that the putative zebrafish abelson homolog has multiple functions in early development, aiding in the differentiation of the central nervous system and also facilitating the differentiation of hematopoietic stem cells in the posterior blood island.