The c-src homologue Src64B is sufficient to activate the Drosophila cellular immune response.

The Drosophila larval cellular immune response involves cells (haemocytes) that can be recruited from a haematopoietic organ known as the lymph gland, as well as a sessile population of cells found just underneath the larval cuticle arranged in a segmental pattern. Overexpression of the Drosophila c-src homologue Src64B disrupts the sessile-haemocyte banding pattern. Though Src64B overexpression induced the formation of specialized haemocytes known as lamellocytes, its hyperactivation had no effect on circulating plasmatocyte concentration. Also, there is evidence of non-autonomous regulation as Src64B activity was observed in non-overexpressing plasmatocytes. Finally, Src64B overexpression induced F-actin formation and Jun kinase activation in plasmatocytes.