Takata, K., Shimanouchi, K., Yamaguchi, M., Murakami, S., Ishikawa, G., Takeuchi, R., Kanai, Y., Ruike, T., Nakamura, R., Abe, Y., Sakaguchi, K. (2004). Damaged DNA binding protein 1 in Drosophila defense reactions.  Biochem. Biophys. Res. Commun. 323(3): 1024--1031.

FBrf0179979

Research paper

We have focused attention on functions of Drosophila damaged DNA binding protein 1 (D-DDB1) in Drosophila hematopoiesis and previously reported that its whole body dsRNA over-expression using a GAL4-UAS targeted expression system results in melanotic tumors and complete lethality. Since the lesions appear to arise as a normal and heritable response to abnormal development, forming groups of cells that are recognized by the immune system and encapsulated in melanized cuticle, D-DDB1 appears to be an essential development-associated factor in Drosophila. To probe the possibility that it contributes to hemocyte development, we used a collagen promoter-GAL4 strain to over-express dsRNA of D-DDB1 in Drosophila hemocytes. The D-DDB1 gene silencing caused melanotic tumors and mortality at the end of larval development. Similarly, it interfered with melanization and synthesis of antimicrobial peptides. Transgenic flies with D-DDB1 gene silencing were found to accumulate abnormal large blood cells, reminiscent of human leukemia, suggesting that D-DDB1 has functions in hemocyte development.