A single cell transcriptome atlas of myeloid blood cell lineages in Drosophila [scRNA-seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE141273 | GEO | 2020/07/24
REPOSITORIES: GEO
Similar Datasets
Project description:The Drosophila lymph gland (LG) is the larval hematopoietic organ comprised of multipotent prohemocytes and mature hemocytes and has been a valuable model for understanding mechanisms underlying the hematopoiesis and immune responses. There are three types of mature hemocytes in the lymph gland; plasmatocytes, lamellocytes, and crystal cells, all of which are analogous to myeloid-lineage blood cells. To date, the Drosophila hematopoietic system has been primarily defined by classical genetic methods that may limit the promise of its advantage as a model. In this study, we used single-cell RNA sequencing method to comprehensively profile the heterogeneity of developing myeloid hemocytes in the wild-type lymph gland and their transitions upon active immunity caused by wasp infestation. Moreover, we compared hemocytes originated from the embryonic and the lymph gland hematopoiesis and unraveled genetic and cellular diversity of two different ancestries. Finally, hemocytes of the Drosophila lymph gland and human immune cells are contrasted at a transcriptome level, highlighting evolutionary conservations of myeloid cells across species. Overall, our single-cell RNA seq analyses disclose the development of myeloid hemocytes at a single-cell level and provide comparative insights into two different lineages of hemocytes in Drosophila and perspectives on the evolution of myeloid cells, serving as an ample resource for revealing essentials of the hematopoiesis.
2020-07-25 | GSE141274 | GEO
Project description:Drosophila blood cells called hemocytes form an efficient barrier against infections and tissue damage. During metamorphosis, hemocytes undergo tremendous changes in their shape and behavior, preparing them for tissue clearance. Yet, the diversity and functional plasticity of pupal blood cells have not been explored. Here, we combine single-cell transcriptomics and high-resolution microscopy to dissect the heterogeneity and plasticity of pupal hemocytes. We identified undifferentiated and specified hemocytes with different molecular signatures associated with distinct functions such as antimicrobial, antifungal immune defense, cell adhesion or secretion. Strikingly, we identified a highly migratory and immuneresponsive pupal cell population expressing typical markers of the posterior signaling center (PSC), which is known to be an important niche in the larval lymph gland. PSC-like cells become restricted to the abdominal segments and are morphologically very distinct from typical Hemolectin (Hml)-positive plasmatocytes. G-TRACE lineage experiments further suggest that PSC-like cells can transdifferentiate to lamellocytes triggered by parasitoid wasp infestation. In summary, we present the first molecular description of pupal Drosophila blood cells, providing insights into blood cell functional diversification and plasticity during pupal metamorphosis.
2023-09-11 | GSE216339 | GEO
Project description:Drosophila adult blood cells originate from larval peripheral hemocytes (derived from the embryonic waves of hematopoiesis) and from larval lymph gland hemocytes. To gain insight into the expression repertoire of Drosophila blood cells, we established the gene expression profiles the adult blood cells and their ascendants.
2021-09-28 | GSE174107 | GEO
Project description:Drosophila hemocytes are the primary defense system required for the animals to thrive and overcome harmful threats and are often compared to the innate immune system of vertebrates. However, their homology has been described using only a limited number of genes and a systematic analysis using transcriptomic data would provide novel insights about the evolution of immune systems. In this study, we performed cross-species comparative analysis using single-cell RNA-sequencing data of Drosophila hemocytes, zebrafish, mouse, and human immune cells in both supervised and unsupervised manner. A small subset of prohemocytes with hematopoietic potential displayed a homology to progenitor populations in vertebrates. Drosophila hemocytes appeared to be largely homologous to the myeloid cells of vertebrates, especially plasmatocytes to monocytes/macrophages and lamellocytes to neutrophils. CG14767 (LAPTM4A) which encodes a lysosomal protein is well conserved in various phagocytic cells suggesting its common role in degradation of foreign uptake. Our results provide deeper understanding in molecular conservation of the Drosophila immune system.
2021-09-26 | GSE184781 | GEO
Project description:In Drosophila melanogaster larval hemolymph, under normal conditions, plasmatocytes and crystal cells represent respectively ~95% and ~5% of hemocytes, while lamellocytes, the third larval cell type, are absent since they are only induced after parasitoid wasp oviposition, their role being the encapsulation-melanization response to eliminate the wasp egg. However, even after induction lamellocytes number remains low, making difficult biochemical studies. Here using the D. melanogaster hopTum-l mutant that constitutively produces a high number of hemocytes, we set up a method to purify lamellocytes and analyzed their major proteins by 2D gel electrophoresis and their biotinylated plasma membrane surface proteins by 1D SDS-PAGE after affinity purification. Mass spectrometry allowed to identify 430 proteins from the 2D spots and 344 from affinity purified proteins, totalizing 639 unique proteins. Known lamellocyte markers such as PPO3 and the integrin myospheroid are among the major proteins and affinity purification led to the detection of other integrins and a large array of integrins associated proteins involved in cell-cell junction formation and function. Overall newly identified proteins indicated that these cells are highly adapted to the encapsulation process but may have also several different physiological functions. This study provides the basis for new lamellocyte studies in vivo and in vitro, and develop markers to search whether different populations coexist, establish their origins and decipher their respective roles in drosophila physiology and immunity.
2024-04-29 | PXD016876 | Pride
Project description:Drosophila blood cells, called the hemocytes, are composed of three distinct cell populations: plasmatocytes (PM), crystal cells (CC), and lamellocytes (LM). These cell types have been extensively characterized based on the expression of a few marker genes and cell morphologies, which are inadequate to classify the complete hemocyte repertoire. Further, intermediate states along the course of maturation of these cell types have been poorly characterized. Here, we used single-cell RNA sequencing (scRNA-seq) to map the Drosophila larval hemocytes across different inflammatory conditions. We identified all known cell types, resolved PMs into different states based on the expression of genes involved in cell cycle, antimicrobial response, and metabolism together with the detection of CC and LM intermediates. Further, we discovered rare cells within CC and LM populations that express the fibroblast growth factor (FGF) ligand branchless (bnl) and receptor breathless (btl), respectively. We demonstrate that both bnl and btl are required for mediating effective immune responses against parasitoid wasp eggs in vivo, highlighting a novel role for FGF signaling in inter-hemocyte crosstalk. Our scRNA-seq analysis reveals the diversity of hemocyte populations and provides a rich resource of gene expression profiles for a systems-level understanding of their functions.
2020-05-16 | GSE146596 | GEO
Project description:Goal: Natural populations of Drosophila melanogaster vary widely in their capacity to resist infection by the parasitic wasp Leptopilina boulardi. To date, little is known about the genetic, cellular and molecular basis underpinning the variation in susceptibility to parasitic wasps. In D.melanogaster populations artificially selected for parasitoid resistance, an increase in the number of circulating hemocytes (blood cells) is observed. One possibility is that this is accompanied by changes in hemocyte activation state, resulting in a successful defence response when exposed to parasitic wasps. We tested this possibility by generating populations that are highly resistant and highly susceptible to the parasitic wasps. We generated these populations after 26 generations of experimental evolution, starting from a single interbred wild caught population. Here, we study how selection for resistance to the parasitic wasp L. boulardi changes the number and type of circulating hemocytes in D. melanogaster larvae using scRNA-seq. Methods: Wild caught D. melanogaster females were collected from Cambridge, UK, to establish an outbreed population. From this, three replicated populations were selected for resistance to L. boulardi strain NSRef for 26 generations (Selection). Another three populations were maintained in the laboratory for 26 generations without being exposed to parasitoid-associated selection pressures (No Selection). At generation 26, second instar D. melanogaster larvae (48-63 hours after fertilization) from each population were infected with L. boulardi for three hours (Infection) or maintained without infection (No infection). 48 hours after, circulating hemocytes from third instar D. melanogaster larvae (96-111 hours after fertilization) from each population were collected in PBS and cleaned in OptiPrep solution (1.09g/ml). 10X Single Cell GEX v2 libraries were prepared and sequenced. CellRanger v2 was used to generate sample cell count matrices. Seurat v3 was used to integrate, normalise and cluster the cell types. Results: We identified novel plasmatocyte cell types, immature and mature lamellocytes and crystal cells. We identify a single lineage of cellular differentiation starting from a self-cycling plasmatocyte population, enriched for genes involved in extracellular matrix organisation, and ending in a mature lamellocyte population that has enriched expression of genes involved in signalling, hemostasis and gluconeogenesis. Immature lamellocytes were overrepresented in populations selected for resistance to parasitoids. Infection with parasitoid resulted in an increase in both immature and mature lamellocytes in circulation. Conclusions: Selection for resistance to the parasitic wasps resulted in the constitutive activation of the D. melanogaster immune system, where plasmatocytes differentiate into immature lamellocytes even where they are not exposed to parasitic wasps. We speculate these constitutive changes assist in mounting a successful defence response when exposed to parasitic wasps.
2020-12-30 | GSE148826 | GEO
Project description:The balance between hematopoietic progenitors and differentiated hemocytes is finely tuned during development. In the larval hematopoietic organ of Drosophila, called the lymph gland, the receptor tyrosine kinase Pvr signals from differentiated cells to maintain a pool of undifferentiated progenitors. However, little is known about the processes that support Pvr function. The small GTPase Ral is involved in the regulation of several membrane trafficking events. Drosophila has a single Ral protein, Rala, which has been implicated in the development of various tissues. Here, we investigated the involvement of Rala in the larval fly hematopoietic system. We discovered that the loss of Rala activity phenocopies Pvr loss of function by promoting hemocyte progenitor differentiation. Moreover, using epistasis analysis, we found that the guanine exchange factor RalGPS lies upstream of Rala in this event, whereas the exocyst and Rab11 are acting downstream. Strikingly, the loss of Rala activity leads to a considerable accumulation of Pvr at the plasma membrane, hence suggesting a trafficking defect and reduced Pvr function. Consistent with this hypothesis, Rala loss of function phenotype in the lymph gland is fully suppressed by constitutive STAT activity, which normally mediates Pvr function in the lymph gland. Together, our findings unravel a novel RalGPS-Rala-exocyst-Rab11 axis for the maintenance of lymph gland homeostasis through Pvr.
2020-05-25 | GSE148035 | GEO
Project description:We report the use of single cell mRNA sequencing to identify new blood cell types, subtypes, genetic markers, and important developmental pathways in the Drosophila lymph gland. We analyzed transcript data for 21,157 cells from wild-type early third instar larvae (90-93 hours after eggs lay at 25 degrees C) which contain reporter constructs that mark progenitors and differentiated cells. We find that lymph gland blood cells can be catorgorized into 9 major clusters. One cluster corrresponds to the niche cells of the posterior signaling center (PSC) that expressed the PSC markers Antennopedia and Collier. Progenitors of the medullary zone (MZ) are found in two distinct clusters (MZ1 and MZ2), both of which express the MZ markers domeless and Tep4. One cluster contains intermediate progenitors of the intermediate zone (IZ), and these express markers such as CG30090, lectin-24A, and MFS3 that we found to be IZ-specific in previous bulk RNA-seq experiments with sorted lymph gland cells. Another cluster (PL) contains plasmatocytes that express NimC1, as well as Hml, Pxn, vkg, and Col4a1. Crystal cells are found in one major population that subclusters into two distinct subclusters (CC1 and CC2) that express the markers lz, Hnt, and proPO.. Another transitory population that we dub proplasmatocytes expresses Hml, Pxn, vkg, and Col4a1, but not PL marker Nimc1 or IZ-markers. One cluster is not well understood, butis highly enriched for cell cycle- and replication stress genes. Pseudotime and Trajectory analysis results in fruther sub-division of these zones based on pseudotime states and aids in building a model of lymph gland development that will be the basis for future studies.
2021-11-03 | GSE168819 | GEO
Project description:Hematological disorders result in perturbed homeostasis of the blood system. However, a comprehensive understanding of how physiological and genetic mechanisms regulate blood cell precursor maintenance and differentiation is lacking. Owing to simplicity and ease of genetic analysis, the Drosophila melanogaster lymph gland (LG) is an excellent model to study hematopoiesis. The LG is a multi-lobed structure compartmentalized into precursor and differentiation zones whose geography and identity is regulated by multiple signalling pathways. While additional molecular and functional subtypes are expected there is a paucity of information on gene expression and regulation of hemocyte homeostasis. Hence, we quantitatively analyzed the LG proteome under conditions that maintain precursors or promote their differentiation in vivo, by perturbing expression of Asrij, a conserved endosomal regulator of hematopoiesis. Although technically demanding, we pooled samples obtained from 1500 larval dissections per genotype and using iTRAQ quantitative proteomics, determined the relative expression levels of polypeptides in Asrij knockout (KO) and overexpressing (OV) LGs in comparison to wild type (control). Mass spectrometry data analysis showed that at least 6.5% of the Drosophila proteome is expressed in wild type LGs.Of 2,133 proteins identified, 780 and 208 proteins were common to the previously reported cardiac tube and hemolymph proteomes, respectively, resulting in the identification of 1238 proteins exclusive to the LG. Perturbation of Asrij levels led to differential expression of 619 proteins, of which 23% have human homologs implicated in various diseases. Proteins regulating metabolism, immune system, signal transduction and vesicle-mediated transport were significantly enriched. Immunostaining of representative candidates from the enriched categories and previous reports confirmed 75% of our results and validated the LG proteome. Our study provides, for the first time, an in vivo proteomics resource for identifying novel regulators of hematopoiesis that will also be applicable to understanding vertebrate blood cell development.
2019-05-15 | PXD010753 | Pride