Fusion Harboring Mast Cells Can Explain Molecular Positivity in Flow Cytometric MRD Negative Core Binding Factor AML.

Molecular measurable residual disease (MRD) can persist in core binding factor acute myeloid leukemia (AML) in otherwise disease-free patients. Utilizing cell sorting followed by fluorescent in situ hybridization, we show that detection is due to mast cells.

Aberrant expression of miR-33a-3p/IGF2 in postmenopausal osteoporosis patients and its role and mechanism in osteoporosis.

BACKGROUND: Postmenopausal osteoporosis (PMOP), the most frequent bone-related disease, is characterized by bone loss and fragile fractures, which is related to low bone density (BMD). This study aimed to illustrate the expression and mechanism of miR-33a-3p in osteoporosis. METHODS: TargetScan and luciferase reporter assay were applied for verifying the relevance between miR-33a-3p and IGF2. Levels of miR-33a-3p, IGF2, Runx2, ALP and Osterix were checked using RT-qPCR and western blotting. hBMSCs proliferation, apoptosis and ALP activity were analyzed by MTT, flow cytometry (FCM) analysis and ALP detection kit, respectively. Moreover, the calcification of cells was assessed using Alizarin Red S staining. The average BMD was evaluated by dual-energy X-ray absorptiometry (DEXA) assay. RESULTS: IGF2 was a target of miR-33a-3p. The level of miR-33a-3p was substantially higher and IGF2 expression was memorably lower in the serum of osteoporosis patients than that in healthy volunteers. Our results also pointed out that miR-33a-3p was reduced and IGF2 expression was enhanced during osteogenic differentiation. We concluded that miR-33a-3p negatively regulated the level of IGF2 in hBMSCs. Besides, miR-33a-3p mimic inhibited the osteogenic differentiation of hBMSCs via inhibiting the level of Runx2, ALP and Osterix and decreasing ALP activity. IGF2 plasmid dramatically reversed the influence of miR-33a-3p mimic on IGF2 expression, hBMSCs proliferation and apoptosis, and osteogenic differentiation of hBMSCs. CONCLUSION: miR-33a-3p affected osteogenic differentiation of hBMSCs by targeting IGF2, indicating a potential use of miR-33a-3p as plasma biomarker and therapeutic target for postmenopausal osteoporosis.

Genomic analyses in Cornelia de Lange Syndrome and related diagnoses: Novel candidate genes, genotype-phenotype correlations and common mechanisms.

Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (>60%) of cases, and the only gene identified to date that results in the severe or classic form of CdLS when mutated. Pathogenic variants in cohesin genes other than NIPBL tend to result in a less severe phenotype. Causative variants in additional genes, such as ANKRD11, EP300, AFF4, TAF1, and BRD4, can cause a CdLS-like phenotype. The common role that these genes, and others, play as critical regulators of developmental transcriptional control has led to the conditions they cause being referred to as disorders of transcriptional regulation (or "DTRs"). Here, we report the results of a comprehensive molecular analysis in a cohort of 716 probands with typical and atypical CdLS in order to delineate the genetic contribution of causative variants in cohesin complex genes as well as novel candidate genes, genotype-phenotype correlations, and the utility of genome sequencing in understanding the mutational landscape in this population.

The impact of Down syndrome-specific non-malignant hematopoietic regeneration in the bone marrow on the detection of leukemic measurable residual disease.

BACKGROUND: Detection of measurable residual disease detection (MRD) by flow cytometry after the first course of chemotherapy is a standard measure of early response in patients with acute myeloid leukemia (AML). Myeloid leukemia associated with Down Syndrome (ML-DS) is a distinct form of AML. Differences in steady-state and regenerating hematopoiesis between patients with or without DS are not well understood. This understanding is essential to accurately determine the presence of residual leukemia in patients with ML-DS. METHODS: A standardized antibody panel defined quantitative antigen expression in 115 follow-up bone marrow (BM) aspirates from 45 patients following chemotherapy for ML-DS or DS precursor B-cell acute lymphoblastic leukemia (B-ALL-DS) with the "difference from normal (ΔN)" technique. When possible, FISH and SNP/CGH microarray studies were performed on sorted cell fractions. RESULTS: 93% of BM specimens submitted post chemotherapy had a clearly identifiable CD34+ CD56+ population present between 0.06% and 2.6% of total non-erythroid cells. An overlapping CD34+ HLA-DRheterogeneous population was observed among 92% of patients at a lower frequency (0.04%-0.8% of total non-erythroid cells). In B-ALL-DS patients, the same CD34+ CD56+ HLA-DRheterogeneous expression was observed. FACS-FISH/Array studies demonstrated no residual genetic clones in the DS-specific myeloid progenitor cells. CONCLUSIONS: Non-malignant myeloid progenitors in the regenerating BM of patients who have undergone chemotherapy for either ML-DS or B-ALL-DS express an immunophenotype that is different from normal BM of non-DS patients. Awareness of this DS-specific non-malignant myeloid progenitor is essential to the interpretation of MRD by flow cytometry in patients with ML-DS.

Integrated analysis of genotype and phenotype reveals clonal evolution and cytogenetically driven disruption of myeloid cell maturation in myelodysplastic syndromes.

BACKGROUND: Myelodysplastic syndromes (MDS) are a heterogenous collection of clonal bone marrow diseases characterized by cytopenias, abnormal karyotypes, molecular abnormalities, and dysplasia by flow cytometry and/or morphology. The progression of MDS to severe cytopenias and/or overt leukemia is associated with the accumulation of additional cytogenetic abnormalities, suggesting clonal evolution. The impact of these accumulated abnormalities on myeloid maturation and the severity of the disease is poorly understood. METHODS: Bone marrow specimens from 16 patients with cytogenetic abnormalities were flow cytometrically sorted into three myeloid populations: progenitors, immature myeloid cells, and mature myeloid cells. Fluorescence in situ hybridization analysis was performed on each to determine the distribution of chromosomal abnormalities during myeloid maturation. RESULTS: Our findings revealed three distinct distributions of cytogenetic abnormalities across myeloid maturation, each of which corresponded to specific cytogenetic abnormalities. Group 1 had continuous distribution across all maturational stages and contained patients with a single cytogenetic aberration associated with good-to-intermediate prognosis; Group 2 had accumulation of abnormalities in immature cells and contained patients with high-risk monosomy 7; and Group 3 had abnormalities defining the founding clone equally distributed across maturational stages while subclonal abnormalities were enriched in progenitor cells and contained patients with multiple, non-monosomy 7, abnormalities with evidence of clonal evolution. CONCLUSIONS: Our findings demonstrate that low-risk abnormalities (e.g., del(20q) and trisomy 8) occurring in the founding clone display a markedly different disease etiology, with respect to myeloid maturation, than monosomy 7 or abnormalities acquired in subclones, which result in a disruption of myeloid cell maturation in MDS.

Genome-wide identification and expression analysis of AUX/LAX family genes in Chinese hickory (Carya cathayensis Sarg.) Under various abiotic stresses and grafting.

Auxin is essential for regulating plant growth and development as well as the response of plants to abiotic stresses. AUX/LAX proteins are auxin influx transporters belonging to the amino acid permease family of proton-driven transporters, and are involved in the transport of indole-3-acetic acid (IAA). However, how AUX/LAX genes respond to abiotic stresses in Chinese hickory is less studied. For the first time identification, structural characteristics as well as gene expression analysis of the AUX/LAX gene family in Chinese hickory were conducted by using techniques of gene cloning and real-time fluorescent quantitative PCR. Eight CcAUX/LAXs were identified in Chinese hickory, all of which had the conserved structural characteristics of AUX/LAXs. CcAUX/LAXs were most closely related to their homologous proteins in Populus trichocarpa , which was in consistence with their common taxonomic character of woody trees. CcAUX/LAXs exhibited different expression profiles in different tissues, indicating their varying roles during growth and development. A number of light-, hormone-, and abiotic stress responsive cis-acting regulatory elements were detected on the promoters of CcAUX/LAX genes. CcAUX/LAX genes responded differently to drought and salt stress treatments to varying degrees. Furthermore, CcAUX/LAX genes exhibited complex expression changes during Chinese hickory grafting. These findings not only provide a valuable resource for further functional validation of CcAUX/LAXs, but also contribute to a better understanding of their potential regulatory functions during grafting and abiotic stress treatments in Chinese hickory.

Deep Learning Technology in Pathological Image Analysis of Breast Tissue.

To explore the application value of the multilevel pyramid convolutional neural network (MPCNN) model based on convolutional neural network (CNN) in breast histopathology image analysis, in this study, based on CNN algorithm and softmax classifier (SMC), a sparse autoencoder (SAE) is introduced to optimize it. The sliding window method is used to identify cells, and the CNN + SMC pathological image cell detection method is established. Furthermore, the local region active contour (LRAC) is introduced to optimize it and the LRAC fine segmentation model driven by local Gaussian distribution is established. On this basis, the sparse automatic encoder is further introduced to optimize it and the MPCNN model is established. The proposed algorithm is evaluated on the pathological image data set. The results showed that the Acc value, F value, and Re value of pathological cell detection of CNN + SMC algorithm were significantly higher than those of the other two algorithms (P < 0.05). The Dice, OL, Sen, and Spe values of pathological image regional segmentation of CNN algorithm were significantly higher than those of the other two algorithms, and the difference was statistically significant (P < 0.05). The accuracy, recall, and F-measure of the optimized CNN algorithm for detecting breast histopathological images were 85.25%, 89.27%, and 80.09%, respectively. In the two databases with segmentation standards, the segmentation accuracy of MPCNN is 55%, 73.1%, 78.8%, and 82.1%. In the deep convolution network model, the training time of the MPCNN algorithm is about 80 min. It shows that when the feature dimension is low, the feature map extracted by MPCNN is more effective than the traditional feature extraction method.

Expression of inflammatory factors and oxidative stress markers in serum of patients with coronary heart disease and correlation with coronary artery calcium score.

Expression characteristics of inflammatory factors interleukin-23 and interleukin-35; oxidative stress markers of malondialdehyde, which is a final product of lipid peroxidation; superoxide dismutase; microRNA-126 and microRNA-146a in serum of patients with coronary heart disease were investigated. Correlation between these biomarkers and CACS (calcification score), as well as the underlying clinical significance were evaluated. A total of 192 patients diagnosed with coronary heart disease were recruited as the observation group, and 69 healthy adults who provided their blood samples were selected as the control group. Enzyme linked immunosorbent assay was carried out to measure the levels of inflammatory factors interleukin-23 and interleukin-35, and the levels of oxidative stress markers of malondialdehyde and superoxide dismutase in serum of the patients and healthy subjects. Real-time fluorescence-based quantitative PCR was performed to measure the expression levels of microRNA-126 and microRNA-146a in serum. The differences in expression of these biomarkers were analyzed, and correlation between these biomarkers and coronary artery calcium score were assessed. The differences in expression levels of interleukin-23, interleukin-35, malondialdehyde, superoxide dismutase, microRNA-126 and microRNA-146a were statistically significant in both groups. The expression levels of interleukin-23, interleukin-35, malondialdehyde, superoxide dismutase, microRNA-126 and microRNA-146a in the observation group were closely associated with severity of the disease. There were positive correlations between coronary artery calcium score and interleukin-23, interleukin-35, malondialdehyde, microRNA-126 and microRNA-146a, respectively; while a negative correlation existed between coronary artery calcium score and superoxide dismutase in the observation group. In conclusion, biomarkers interleukin-23, interleukin-35, malondialdehyde, superoxide dismutase, microRNA-126 and microRNA-146a were abnormally expressed in serum of patients with coronary heart disease, implicating their association with onset and progression of the disease. The biomarkers were found to be correlated with coronary artery calcium score. Detection of changes of related biomarkers in serum may have certain value in diagnosis of disease formation, as well as assessment of disease severity.

Identification and expression analysis of auxin-responsive GH3 family genes in Chinese hickory (Carya cathayensis) during grafting.

The GH3 genes play vital roles in auxin homeostasis by conjugating excess auxin to amino acids. However, how GH3 genes function during grafting in Chinese hickory (Carya cathayensis) is largely unknown. Here, based on the transcriptome database, a comprehensive identification and expression profiling analysis of 12 GH3 genes in Chinese hickory were performed. Phylogenetic analysis indicated that CcGH3-x exists in a specific subfamily. To understand the roles of CcGH3 genes, tissue-specific expression and the response to different phytohormones were determined. Expression profiles of GH3 genes of Chinese hickory during grafting were analysed. The data suggested that 10 CcGH3 genes were down-regulated at an early stage of grafting, indicating that auxin homeostasis regulated by the CcGH3 family might be inhibited at initial stages. At the completion of grafting, expression levels of members of the CcGH3 family were restored to normal levels. Endogenous auxin levels were also measured, and the data showed that free auxin decreased to the lowest level at an early stage of grafting, and then increased during grafting. Auxin amino acid conjugation increased at an early stage of grafting in rootstock, and then decreased with progression of the graft union. Our results demonstrate that the reduced expression of CcGH3 family genes during grafting might contribute to the release of free auxin, making an important contribution to the recovery of auxin levels after grafting.

Melatonin regulates the functional components of photosynthesis, antioxidant system, gene expression, and metabolic pathways to induce drought resistance in grafted Carya cathayensis plants.

The Chinese hickory (Carya cathayensis) is an economically important tree species popular for its nuts. However, the tree requires a long time to reach the nut-producing phase. To overcome this problem, grafting is widely used to reduce the time from the vegetative to the reproductive phase. This tree species also faces many environmental challenges due to climate change; drought is an important factor affecting growth and development. Here, we designed an experiment to assess the protective efficiency of melatonin in grafted Chinese hickory plants under drought stress. The results revealed that exogenously applied melatonin successfully recovered the growth of grafted Chinese hickory plants and improved photosynthetic efficiency. Exogenously applied melatonin also boosted the antioxidative defense system of the plants under drought stress, resulting in enhanced reactive oxygen species (ROS) scavenging. The accumulation of compatible solutes such as total soluble sugars and proline was also triggered by melatonin. Moreover, the analyses using metabolomics revealed that drought-stressed plants treated with melatonin regulated key metabolic pathways such as phenylpropanoid, chlorophyll and carotenoid biosynthesis, carbon fixation, and sugar metabolism. To further validate the physiological, biochemical, and metabolomic factors, we studied the molecular mechanisms by analyzing the expression of key genes involved in chlorophyll metabolism (chlorophyllase, CHLASE), antioxidative defense (superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; peroxidase, POD), and phenylalanine ammonia-lyase (PAL). Exogenously applied melatonin significantly regulated the transcript levels of key genes involved in the biological processes mentioned above. Melatonin also showed crosstalk with other hormones (zeatin, gibberellin A14, 24-epibrassinolide, jasmonic acid, and abscisic acid) to regulate the physiological processes. The results of this study show that melatonin regulates biological processes at the metabolic and molecular levels to resist drought stress.

Quantitative succinyl-proteome profiling of Chinese hickory (Carya cathayensis) during the grafting process.

BACKGROUND: Chinese hickory (Carya cathayensis) is a popular nut plant having high economic value. Grafting is applied to accelerate the transition from vegetative phase to reproductive phase. Lysine succinylation occurs frequently in the proteins associated with metabolic pathways, which may participate in the regulation of the grafting process. However, the exact regulatory mechanism underlying grafting process in Chinese hickory has not been studied at post-translational modification level. RESULTS: A comprehensive proteome-wide lysine succinylation profiling of Chinese hickory was explored by a newly developed method combining affinity enrichment and high-resolution LC-MS/MS. In total, 259 succinylation sites in 202 proteins were identified, representing the first comprehensive lysine succinylome in Chinese hickory. The succinylation was biased to occur in the cytosolic proteins of Chinese hickory. Moreover, four conserved succinylation motifs were identified in the succinylated peptides. Comparison of two grafting stages of Chinese hickory revealed that the differential expressed succinylated proteins were mainly involved in sugar metabolism, carbon fixation, amino acid metabolism and plant-pathogen interaction. Besides, seven heat shock proteins (HSPs) with 11 succinylation sites were also identified, all of which were observed to be up-regulated during the grafting process. CONCLUSIONS: Succinylation of the proteins involved in amino acid biosynthesis might be required for a successful grafting. Succinylated HSPs might play a role in stress tolerance of the grafted Chinese hickory plants. Our results can be a good resource for functional validation of the succinylated proteins and a starting point for the investigation of molecular mechanisms during lysine succinylation occurring at grafting site.

Identification and expression profiling of the Aux/IAA gene family in Chinese hickory (Carya cathayensis Sarg.) during the grafting process.

Auxin is an essential regulator in various aspects of organism growth and development. Members of the Aux/IAA family of genes encode short-lived nuclear proteins and mediate the responses of auxin-regulated gene expression. Here, the first identification and characterization of 22 cDNAs encoding the open reading frame of the Aux/IAA family in Chinese hickory (named as CcIAA) has been performed. The proteins encoded by these genes contain four whole or partially conserved domains of the Aux/IAA family. Phylogenetic analysis indicated that CcIAAs were unevenly distributed among eight different subgroups. The spatio-specific expression profiles showed that most of the CcIAAs preferentially expressed in specific tissues. Three CcIAA genes, including CcIAA11, CcIAA27a2 and CcIAAx, were predominantly expressed in stem. The predominant expression of CcIAA genes in stems might play important roles in vascular reconnection during the graft process. Furthermore, expression profiles of Aux/IAA genes during the grafting process of Chinese hickory have been analysed. Our data suggested that 19 CcIAAs were down-regulated and 3 CcIAAs (including CcIAA28, CcIAA8a and CcIAA27b) were induced, indicating their specializations during the grafting process. The involvement of CcIAA genes at the early stage after grafting gives us an opportunity to understand the role of auxin signalling in the grafting process.

Comparative Proteomic Analysis of the Graft Unions in Hickory (Carya cathayensis) Provides Insights into Response Mechanisms to Grafting Process.

Hickory (Carya cathayensis), a tree with high nutritional and economic value, is widely cultivated in China. Grafting greatly reduces the juvenile phase length and makes the large scale cultivation of hickory possible. To reveal the response mechanisms of this species to grafting, we employed a proteomics-based approach to identify differentially expressed proteins in the graft unions during the grafting process. Our study identified 3723 proteins, of which 2518 were quantified. A total of 710 differentially expressed proteins (DEPs) were quantified and these were involved in various molecular functional and biological processes. Among these DEPs, 341 were up-regulated and 369 were down-regulated at 7 days after grafting compared with the control. Four auxin-related proteins were down-regulated, which was in agreement with the transcription levels of their encoding genes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the 'Flavonoid biosynthesis' pathway and 'starch and sucrose metabolism' were both significantly up-regulated. Interestingly, five flavonoid biosynthesis-related proteins, a flavanone 3-hyfroxylase, a cinnamate 4-hydroxylase, a dihydroflavonol-4-reductase, a chalcone synthase, and a chalcone isomerase, were significantly up-regulated. Further experiments verified a significant increase in the total flavonoid contents in scions, which suggests that graft union formation may activate flavonoid biosynthesis to increase the content of a series of downstream secondary metabolites. This comprehensive analysis provides fundamental information on the candidate proteins and secondary metabolism pathways involved in the grafting process for hickory.

Gene fusions PAFAH1B1-USP6 and RUNX2-USP6 in aneurysmal bone cysts identified by next generation sequencing.

Aneurysmal bone cyst (ABC) is a locally aggressive, expansile, typically multilocular cystic bone tumor. ABC was previously thought to be a non-neoplastic lesion; however, it is now considered to be neoplasm that features recurrent chromosomal translocations resulting in gene fusions between ubiquitin specific peptidase 6 (USP6) and multiple partners, including COL1A1, CDH11, TRAP150, ZNF90 and OMD. Using next generation sequencing (NGS), we uncovered two fusion partners of USP6 in two ABCs: platelet activating factor acetylhydrolase 1b regulatory subunit 1 (PAFAH1B1), which is known to contribute to tumorigenesis in lung cancer, and runt-related transcription factor 2 (RUNX2), which is known to regulate osteoblastic differentiation, osteosarcoma tumorigenesis and its metastasis. In our study, the PAFAH1B1-USP6 fusion consisted of the promoter of PAFAH1B1 fused to the 5'-untranslated region (5'-UTR) of USP6 and was discovered in a typical ABC. The RUNX2-USP6 fusion had the promoter and a short coding region of RUNX2 fused to the translation start codon of USP6 and was detected in an unusually aggressive ABC with an osteosarcoma-like soft tissue extension. Our findings not only expanded the repertoire of the partner genes of USP6 in ABC but also can serve as a reference for future studies to better understand the correlation between various gene fusions and the progression of ABC.

Drosophila Nipped-B Mutants Model Cornelia de Lange Syndrome in Growth and Behavior.

Individuals with Cornelia de Lange Syndrome (CdLS) display diverse developmental deficits, including slow growth, multiple limb and organ abnormalities, and intellectual disabilities. Severely-affected individuals most often have dominant loss-of-function mutations in the Nipped-B-Like (NIPBL) gene, and milder cases often have missense or in-frame deletion mutations in genes encoding subunits of the cohesin complex. Cohesin mediates sister chromatid cohesion to facilitate accurate chromosome segregation, and NIPBL is required for cohesin to bind to chromosomes. Individuals with CdLS, however, do not display overt cohesion or segregation defects. Rather, studies in human cells and model organisms indicate that modest decreases in NIPBL and cohesin activity alter the transcription of many genes that regulate growth and development. Sister chromatid cohesion factors, including the Nipped-B ortholog of NIPBL, are also critical for gene expression and development in Drosophila melanogaster. Here we describe how a modest reduction in Nipped-B activity alters growth and neurological function in Drosophila. These studies reveal that Nipped-B heterozygous mutant Drosophila show reduced growth, learning, and memory, and altered circadian rhythms. Importantly, the growth deficits are not caused by changes in systemic growth controls, but reductions in cell number and size attributable in part to reduced expression of myc (diminutive) and other growth control genes. The learning, memory and circadian deficits are accompanied by morphological abnormalities in brain structure. These studies confirm that Drosophila Nipped-B mutants provide a useful model for understanding CdLS, and provide new insights into the origins of birth defects.

Clonal genetic and hematopoietic heterogeneity among human-induced pluripotent stem cell lines.

Induced pluripotent stem cells (iPSCs) hold great promise for modeling human hematopoietic diseases. However, intrinsic variability in the capacities of different iPSC lines for hematopoietic development complicates comparative studies and is currently unexplained. We created and analyzed 3 separate iPSC clones from fibroblasts of 3 different normal individuals using a standardized approach that included excision of integrated reprogramming genes by Cre-Lox mediated recombination. Gene expression profiling and hematopoietic differentiation assays showed that independent lines from the same individual were generally more similar to one another than those from different individuals. However, one iPSC line (WT2.1) exhibited a distinctly different gene expression, proliferation rate, and hematopoietic developmental potential relative to all other iPSC lines. This "outlier" clone also acquired extensive copy number variations (CNVs) during reprogramming, which may be responsible for its divergent properties. Our data indicate how inherent and acquired genetic differences can influence iPSC properties, including hematopoietic potential.

Topological constraint in high-density cells' tracking of image sequences.

The multi-target tracking in cell image sequences is the main difficulty in cells' locomotion study. Aim to study cells' complexity movement in high-density cells' image, this chapter has proposed a system of segmentation and tracking. The proposed tracking algorithm has combined overlapping and topological constraints with track inactive and active cells, respectively. In order to improve performance of algorithm, size factor has been introduced as a new restriction to quantification criterion of similarity based on Zhang's method. And the distance threshold for transforming segmented image into graph is adjusted on considering the local distribution of cells' district in one image. The improved algorithm has been tested in two different image sequences, which have high or low contrast ration separately. Experimental results show that our approach has improved tracking accuracy from 3% to 9% compared with Zhang's algorithm, especially when cells are in high density and cells' splitting occurred frequently. And the final tracking accuracy can reach 90.24% and 77.08%.

Genetic control of programmed cell death (apoptosis) in Drosophila.

Programmed cell death, or apoptosis, is a highly conserved cellular process that has been intensively investigated in nematodes, flies and mammals. The genetic conservation, the low redundancy, the feasibility for high-throughput genetic screens and the identification of temporally and spatially regulated apoptotic responses make Drosophila melanogaster a great model for the study of apoptosis. Here, we review the key players of the cell death pathway in Drosophila and discuss their roles in apoptotic and non-apoptotic processes.