Programmed cell death in the Drosophila central nervous system midline
نویسندگان
چکیده
BACKGROUND During the development of the central nervous system, large numbers of cells die by programmed cell death. This process requires the activity of specific gene products and subserves functions that include regulating the sizes of interacting cell populations and removing cells that provide transient functions. Resolution of programmed cell death often involves the elimination of dying cell corpses by phagocytic macrophages. In Drosophila, the reaper gene plays a crucial role in mediating programmed cell death; chromosomal deficiencies which remove reaper result in an absence of programmed cell death. We have used a reaper-deficiency mutant strain Df(3R)H99 (or H99), in conjunction with strains containing cell-type-specific markers, to examine the role of programmed cell death in differentiation of the embryonic central nervous system midline. RESULTS Midline cell death was identified both by the presence of excess midline cells in H99 mutants and by the engulfment of dying midline cells by macrophages in wild-type embryos. These developmental deaths are lineage-specific: prominent midline glial death was observed, while little if any death was detected among the ventral unpaired median neurons. Examination of H99 mutants indicates that cell death is not required for the formation of macrophage precursors, or for their subsequent migration throughout the embryo; however, in the absence of dying cells, macrophage precursors do not exhibit morphological differentiation or phagocytosis. In both wild-type and H99 mutant embryos, a subset of macrophages migrate along the ventral midline. This midline migration is not observed in single-minded mutants, in which ventral midline cells fail to develop. CONCLUSIONS Programmed cell death plays a crucial role in the development of the central nervous system midline, and dying midline cells are rapidly eliminated by phagocytic macrophages. It seems that the generation of engulfment signals in cells undergoing programmed cell death is downstream of reaper gene function, and that central nervous system midline and/or ventral epidermal cells provide directional cues for migrating macrophages.
منابع مشابه
Cooperative functions of the reaper and head involution defective genes in the programmed cell death of Drosophila central nervous system midline cells.
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 gl...
متن کاملThe Role of Caspase 9 during Programmed Cell Death in Ciliary Ganglia of Chick Embryos
During programmed cell death (PCD) apoptosis is controlled by many factors such as proteases. With no specific protease (s) known during PCD in the developing nervous system so far, we sought to determine if any specific protease (s) is involved in this process and therefore used different protease inhibitors during PCD (from embryonic day 6 to 10) in chick embryos. Among the inhibitors commerc...
متن کاملProgrammed cell death during Drosophila embryogenesis.
The deliberate and orderly removal of cells by programmed cell death is a common phenomenon during the development of metazoan animals. We have examined the distribution and ultrastructural appearance of cell deaths that occur during embryogenesis in Drosophila melanogaster. A large number of cells die during embryonic development in Drosophila. These cells display ultrastructural features that...
متن کاملImpact of Duration and Severity of Persistent Pain on Programmed Cell Death
Programmed cell death is a highly regulated form of cell death, mostly distinguished by the activation of a family of cystein-aspartate proteases (caspases) that cleave various proteins resulting in morphological and biochemical changes characteristic of this form of cell death. Several recent studies have addressed the role of programmed cell death in inflammatory and chronic pain states. Casp...
متن کاملImpact of Duration and Severity of Persistent Pain on Programmed Cell Death
Programmed cell death is a highly regulated form of cell death, mostly distinguished by the activation of a family of cystein-aspartate proteases (caspases) that cleave various proteins resulting in morphological and biochemical changes characteristic of this form of cell death. Several recent studies have addressed the role of programmed cell death in inflammatory and chronic pain states. Casp...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Current Biology
دوره 5 شماره
صفحات -
تاریخ انتشار 1995