Cooperative Functions of the Reaper and Head involution defective Genes in the Programmed Cell Death of Drosophila Central Nervous System Midline Cells

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 94; no. 10; pp. 5131 - 5136
• Main Authors: Zhou, L., Schnitzler, A., Agapite, J., Schwartz, L. M., Steller, H., Nambu, J. R.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 13-05-1997; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences of the USA
• Subjects: Animals; Apoptosis; Axons; beta-Galactosidase - biosynthesis; Biological Sciences; Biology; Cell death; Central nervous system; Crosses, Genetic; Drosophila; Drosophila - cytology; Drosophila - genetics; Drosophila - physiology; Drosophila Proteins; Embryo, Nonmammalian - cytology; Embryo, Nonmammalian - physiology; Embryonic cells; Embryos; Gene Expression Regulation, Developmental; Genes; Genes, Insect - genetics; Genes, Insect - physiology; Insects; Killing; Multigene Family; Nervous system; Nervous System - cytology; Nervous System - embryology; Nervous System Physiological Phenomena; Neuroglia; Neuroglia - cytology; Neuroglia - physiology; Neurons; Peptide Biosynthesis; Peptides - genetics; Recombinant Proteins - biosynthesis
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.94.10.5131

In Drosophila, the chromosomal region 75C1-2 contains at least three genes, reaper (rpr), head involution defective (hid), and grim, that have important functions in the activation of programmed cell death. To better understand how cells are killed by these genes, we have utilized a well defined set of embryonic central nervous system midline cells that normally exhibit a specific pattern of glial cell death. In this study we show that both rpr and hid are expressed in dying midline cells and that the normal pattern of midline cell death requires the function of multiple genes in the 75C1-2 interval. We also utilized the P[UAS]/P[Gal4] system to target expression of rpr and hid to midline cells. Targeted expression of rpr or hid alone was not sufficient to induce ectopic midline cell death. However, expression of both rpr and hid together rapidly induced ectopic midline cell death that resulted in axon scaffold defects characteristic of mutants with abnormal midline cell development. Midline-targeted expression of the baculovirus p35 protein, a caspase inhibitor, blocked both normal and ectopic rpr- and hid-induced cell death. Taken together, our results suggest that rpr and hid are expressed together and cooperate to induce programmed cell death during development of the central nervous system midline.