Programmed cell death in development.
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Animals↗
Biomedical subjects
Kimberly McCall
Publications and source records attributed to Kimberly McCall.
Role of programmed cell death in patterning the Drosophila antennal arista.
Programmed cell death is a critical process for the patterning and sculpting of organs during development. The Drosophila arista, a feather-like structure at the tip of the antenna, is composed of a central core and several lateral branches. A homozygous viable mutation in the thread gene, which encodes an inhibitor of apoptosis protein, produces a branchless arista. We have found that mutations in the proapoptotic gene hid lead to numerous extra branches, suggesting that the level of cell death determines the number of branches in the arista. Consistent with this idea, we have found that thread mutants show excessive cell death restricted to the antennal imaginal disc during the middle third instar larval stage. These findings point to a narrow window of development in which regulation of programmed cell death is essential to the proper formation of the arista.
Animals↗
Eggs over easy: cell death in the Drosophila ovary.
Programmed cell death is the most common fate of female germ cells in Drosophila and many animals. In Drosophila, oocytes form in individual egg chambers that are supported by germline nurse cells and surrounded by somatic follicle cells. As oogenesis proceeds, 15 nurse cells die for every oocyte that is produced. In addition to this developmentally regulated cell death, groups of germ cells or entire egg chambers may be induced to undergo apoptosis in response to starvation or other insults. Recent findings suggest that these different types of cell death involve distinct genetic pathways. This review focuses on progress towards elucidating the molecular mechanisms acting during programmed cell death in Drosophila oogenesis.
Animals↗
Detection of apoptosis in Drosophila.
Drosophila has unique genetic and cell biological advantages as a model system for the study of apoptosis. Many cell death genes are evolutionarily conserved between flies and mammals. Cell death can be induced by environmental stimuli and normally occurs during diverse developmental processes in Drosophila. Here, we review several approaches for detecting cell death in Drosophila. We provide detailed protocols for labeling apoptotic cells in the embryo and ovary using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and acridine orange. Additionally, we describe methods for ectopically expressing cell death genes in the eye and the use of transgenic flies for the detection of genetic interactions among cell death genes.
Acridine Orange↗
Germline cell death is inhibited by P-element insertions disrupting the dcp-1/pita nested gene pair in Drosophila.
Germline cell death in Drosophila oogenesis is controlled by distinct signals. The death of nurse cells in late oogenesis is developmentally regulated, whereas the death of egg chambers during mid-oogenesis is induced by environmental stress or developmental abnormalities. P-element insertions in the caspase gene dcp-1 disrupt both dcp-1 and the outlying gene, pita, leading to lethality and defective nurse cell death in late oogenesis. By isolating single mutations in the two genes, we have found that the loss of both genes contributes to this ovary phenotype. Mutants of pita, which encodes a C2H2 zinc-finger protein, are homozygous lethal and show dumpless egg chambers and premature nurse cell death in germline clones. Early nurse cell death is not observed in the dcp-1/pita double mutants, suggesting that dcp-1+ activity is required for the mid-oogenesis cell death seen in pita mutants. dcp-1 mutants are viable and nurse cell death in late oogenesis occurs normally. However, starvation-induced germline cell death during mid-oogenesis is blocked, leading to a reduction and inappropriate nuclear localization of the active caspase Drice. These findings suggest that the combinatorial loss of pita and dcp-1 leads to the increased survival of abnormal egg chambers in mutants bearing the P-element alleles and that dcp-1 is essential for cell death during mid-oogenesis.
Amino Acid Sequence↗