The Drosophila ovary is a well-established system for studying stem cell biology in vivo ( Lin, 2002 ; Xie et al. In a structure known as the germarium, at the tip of the Drosophila ovary, two or three GSCs can be reliably recognized by their size (the largest germ cells), location. For example, ISCs receive self-renewal. INTRODUCTION. is also required in the escort cells as compromising H1 in the escort cells leads to accumulation of GSC-like cells and escorts cell death [27]. In this work, we demonstrate a powerful new tool for the manipulation of the stromal component of a well-established Drosophila stem cell niche. Germline stem cell (GSC) self-renewal and differentiation into gametes is regulated by both intrinsic factors in the germ line as well as extrinsic factors from the surrounding somatic niche. We show. However, the underlying mechanism for the development of stem cell niche remains largely unclear. Schematic illustrations for some of the best-characterized stem cell niches. The existence of niches has long been predicted from mammalian studies, but identifying stem cells in their native environments in vivo has remained a challenge in most vertebrates. An overview of the Drosophila testis. 1-3, 29, 30 In this study, using Drosophila as a model, we identified RpS13 as a crucial factor that could control the homeostasis of GSC fates, demonstrating that RpS13 is essential for GSC self-renewal. The piRNA (Piwi-interacting RNA) pathway, which represses transposable elements (TEs), is required in ECs to prevent the accumulation of undifferentiated germ cells (germline tumor phenotype). Systemic signals originating outside the niche also affect stem cell and progenitor behavior. Sexual differences within the adult GSC niches have been well-characterized . The GSC niche is composed of cap cells, terminal filament cells, and escort cells (Kirilly and Xie, 2007). The mechanisms that modulate and limit the signaling output of adult stem cell niches remain poorly understood. 053 Corpus ID: 229321422; A Progressive Somatic Cell Niche Regulates Germline Cyst Differentiation in the Drosophila Ovary @article{Shi2020APS, title={A Progressive Somatic Cell Niche Regulates Germline Cyst Differentiation in the Drosophila Ovary}, author={Jingyuan Shi and Zhen Jin and Yaxin. from the stem cell niche, a specialized microenvironment, and their functions are spatially restricted. Two or three female GSCs are maintained in a structure called a niche at the anterior tip of the ovary. Since that time, identification of niche components and our understanding of how the niche maintains. The Drosophila ovary germline stem cell (GSC) niche is a well-studied model, which is comprised of cap cells that provide anchorage and maintenance signals for GSCs to maintain oogenesis. Proc Natl Acad Sci U S A. Stem cells reside in a niche, a local environment whose cellular and molecular complexity is still being elucidated. Proc. The Drosophila testis provides an excellent in vivo system to study stem cells’ niche interactions at the cellular and molecular levels [3, 11–33]. Further, after perturbations inducing loss. Stem cell self-renewal is controlled by concerted actions of extrinsic niche signals and intrinsic factors in a variety of systems. The Female GSC Niche Contains a Second Type of Stem Cell. Here we found that the expression of a zinc transporter Catsup is essential for ovary morphogenesis. Drosophila germline stem cells (GSCs) have become an attractive system for studying stem cell biology, including the niche structure and function and self-renewal mechanisms. Production of proliferative follicle cells (FCs) and quiescent escort cells (ECs) by follicle stem cells (FSCs) in adult Drosophila ovaries is regulated by niche signals from anterior (cap cells, ECs) and posterior (polar FCs) sources. elegans, their niches were among the first to be. In stem cell biology, loss of niche adhesion is associated with stem cell aging and terminal differentiation [3, 22, 28]. Stem cells provide an origin for ovarian germ line cells, whereas somatic cells develop the capsule of the germarium. Keywords: Drosophila ovary, germline stem cell, somatic stem cell, escort stem cell Cell Research (2007) 17: 15-25. Stem cells and their progenitors are maintained within a microenvironment, termed the niche, through local cell-cell communication. Drosophila niche is composed of somatic terminal filament cells, cap cells and escort cells. The Hh pathway is present and active in the Drosophila somatic testis. Boyle, M. Here, we found that histone H1 depletion in escort cells (ECs) resulted in an increase of spectrosome-containing cells (SCCs), an. Many of the mechanistic insights into how. Bhaskar et al. First, as in the FSC niche, the Wnt/Wg signaling pathway is a key stem cell niche signal in many and mammalian epithelial tissues. Cap cells (purple) and escort stem cells (green) function as a niche to maintain GSCs (red), allowing germ cells outside the. 1 Introduction In recent years, the stem cell field has opened a new venue in regenerative and reproductive medicine. Ovarian germline stem cells (GSCs) of Drosophila melanogaster provide a valuable in vivo model to investigate how the adult stem cell identity is maintained and the differentiation of the daughter cells is regulated. Stem cell niches provide localized signaling molecules to promote stem cell fate and to suppress differentiation. produce more escort cells. Notch signaling controls the niche formation and maintenance, while aging affects BMP signaling activity and E-cadherin expression in niche cells. We had previously identified an autonomous role of the histone H1 in germline stem cell (GSC) maintenance. An outstanding question in the field is whether the Hippo pathway regulates proliferation of cells comprising stem cell niches during development in order to ensure that adult organs have an appropriate number of stem cells and stem cell niches . Drosophila melanogaster female GSCs have been utilized as a powerful model system to study the role of niche signals in the self-renewal and differentiation of stem cells, as it is relatively easy to anatomically visualize and genetically manipulate GSCs and their niche (Ables and. Our studies reveal that a previously unknown type of stem cell, escort stem cells, closely contacts the GSCs within the niche at the tip of each Drosophila ovariole. Oh Y. Taken together, the study of the Drosophila ovary and testis has greatly enhanced our understanding of the basic principles that govern niche formation and function. We have generated a bric-a-brac 1 (bab1)-Gal4 line that drives UAS expression in many somatic ovary cell types from early larval stages. 1242/dev. (A) The Drosophila ovarian stem cell niche controls cystoblast formation. The stem cell niche: lessons from the Drosophila testis. We show that Notch. Though initially touted as the ATP generating machines for carrying various cellular processes, it is now increasingly becoming clear that mitochondrial processes alone can. The stem cell niche provides a microenvironment composed of cellular structures or extracellular matrix in which stem cells are maintained as undifferentiated (1–6). , 2000). Moreover, while both niches utilize BMP signaling, the testis. Besides the complex signaling. Studying stem cells in vivo in Drosophila. Adult GSCs are also found in Drosophila and mammalian testes and might exist in a. When Drosophila germline stem cells divide (), 1 daughter cell (the cystoblast) looses niche contact and undergoes 4 transit-amplifying divisions to create a cyst of 16 cystocytes, which remain. , 2011; Sahai-Hernandez et al. In the Drosophila testis, Janus kinase–signal transducer and activator of transcription (JAK-STAT)This study used single-cell RNA-sequencing (scRNA-seq) to build a comprehensive cell atlas of the adult Drosophila ovary that contains transcriptional profiles for every major cell type in the ovary, including the germline stem cells and their niche cells, follicle stem cells, and previously undescribed subpopulations of escort cells. Development, 140 (2013),. Here, we focus on the Drosophila ovarian germline stem cell niche and review recent studies that have begun to reveal how intricate crosstalk between various signaling pathways regulates stem cell maintenance, how the extracellular matrix modulates the signaling output of the niche and how epigenetic programming influences cell development and. Catsup knockdown in escort cells results in defects of. Here, we present a scRNA study of somatic ECs,one daughter stem cell that remains associated with the cap cell niche and a second daughter that is displaced away from the niche and as a result diff erentiates. The ovarian GSC niche also contains a second somatic cell type called the escort stem cells (ESCs) (Decotto and Spradling, 2005,. PLoS Genet. JAK-STAT signaling is a highly conserved regulator of stem cells and their niches. Follicle stem cells (FSC; purple dashed line) create pre-follicle cells that surround the 16-cell cyst, giving rise to an egg chamber or follicle that leaves the. Mating stimulates GSC proliferation. Germline stem cells also contact the anterior escort cells, and here we report that anterior escort cells are. Germline stem cells in the Drosophila ovary are maintained by a somatic niche. Recent studies in Drosophila have shown that the dynamics of Piwi and its associated piRNAs, a protein-RNA complex for gene silencing, are required in not only germ cells. Gonzalez-Reyes A (2006) Genetic dissection of a stem cell niche: the case of the Drosophila ovary. Stem cells, which can self-renew and generate differentiated cells, have been shown to be controlled by surrounding microenvironments or niches in several adult tissues. GSCs are embedded into a specialized cellular microenvironment, the so-called stem cell niche. The stem cell niches at the apex of Drosophila ovaries and testes have been viewed as distinct in two major respects. cub. In males, GSCs physically associate with 10–15 somatic hub cells, which also house a second stem cell population, the somatic cyst stem cells (CySCs). Through single-cell gene expression profiling. Cell Stem Cell, 1 (2007), pp. Here we show that ECs, FSCs, and FCs develop from common pupal precursors, with different fates. The stability of the niche function is of great importance in regulating stem cell behaviour, replaceability and competition among stem cells. Kirilly D, Wang S, Xie T (2011) Self-maintained escort cells form a germline stem cell differentiation niche. The terminal filament (TF), cap cells (CpCs), and anterior-most escort cells (ECs) form a GSC niche [5,6]. Because GSCs can be easily identified and gene functions can be readily manipulated in Drosophila and C. Germline stem cells also contact the anterior escort cells, an. In the germarium of the Drosophila ovary, developing germline cysts are surrounded by a population of somatic escort cells that are known to function as the niche cells for germline differentiation; 1 however, the underlying molecular mechanisms of this niche function remain poorly understood. In Drosophila ovary, niche is composed of somatic cells, including terminal filament cells (TFCs), cap cells (CCs) and escort cells (ECs), which provide extrinsic. The core of the. Similar to the male gonad, the ovary has a stem cell niche consisting of terminal filament cells (TFCs), somatic cap cells and escort stem cells (ESCs), located in the germarium. In the Drosophila ovary, the anterior end of the GSC remains in contact with a somatic niche. 9 Work in Drosophila has been instrumental to the discovery that many stem cells reside in and rely on a special microenvironment, the stem cell niche. ESC daughters encase newly produced cystoblasts and remain tightly associated as they grow into 16-cell cysts and. Van de Bor et al. Dyn. Acad. Static images provide a thumbnail view of folliculogenesis but imperfectly capture the dynamic cellular interactions that underlie follicle production. The Drosophila ovary provides an excellent system for studying factors required to establish and maintain stem cells (1. 1,2 The Drosophila male and female germline stem cell niches have been characterized in detail, and these studies found that the niche is both necessary for maintaining the stem. The anatomic structure of the Drosophila gonad is well defined. Decapentaplegic (Dpp) is secreted from the germline stem cell (GSC) niche to activate Bone Morphogenic Protein (BMP) signaling in GSCs for their self-renewal and is restricted in the differentiation niche for daughter cell differentiation. Germline Stem Cell Niche in the Drosophila Testis. Over the years, Drosophila has served as a wonderful genetically tractable model system to unravel various facets of tissue-resident stem cells in their microenvironment. However, the underlying mechanism for the development of stem cell niche remains largely unclear. Emerging niches mature through distinct stages to form the adult niche and enable proper stem cell support. a H3K9 methyltransferase in Drosophila, is required in GSCs for controlling self-renewal and in escort cells for. Nutrient signals act on multiple cell types to coordinate proper GSC response to diet. Many stem cells reside in a special microenvironment, called the niche, to maintain their identity []. Germline stem cells (GSCs) can generate haploid gametes, sperms or oocyte, which are responsible for transmitting genetic information from generation to generation. In the Drosophila ovary, cap cells, possibly along with escort stem cells (ESCs), form a functional GSC niche (Decotto and Spradling, 2005, Xie and Spradling, 2000), and the niche-expressing Dpp/BMP2-4, Gbb/BMP5-8, and PIWI are essential for controlling GSC self-renewal (Cox et al. Escort cells (yellow dashed line) signal to GSCs to promote differentiation. 1). Tumors are caused by derepression of decapentaplegic (dpp), which prevents cystoblast differentiation. Development 131 , 1353–1364 (2004). The Drosophila germline stem cells (GSCs) reside in a somatic cell niche [1, 2]. The niche is. Lsd1 binds to fewer sites in cap cells. The stem. Stem cell self-renewal and the daughter cell differentiation are tightly regulated by the respective niches, which produce extrinsic cues to support the proper development. The number of stem cells that self-renews and differentiates must be tightly controlled to maintain tissue homeostasis. Drosophila niche is composed of somatic terminal filament cells, cap cells and escort cells. Jones, D. A multicellular organism is not simply a mass of cells but rather is a conglomeration of dis-Multiple signaling pathways guide the behavior and differentiation of both germline stem cells (GSCs) and somatic follicle stem cells (FSCs) in the Drosophila germarium, necessitating careful control of signal generation, range and responses. Author Summary The mechanisms that govern the formation, size and signaling output of in vivo niches remain poorly understood. Development 138:5087–5097. While both contain germline stem cells, the testis niche also contains “cyst progenitor” stem cells, which divide to produce somatic cells that encase de-veloping germ cells. Thus, the niche is required for appropriate tissue homeostasis. Stem cell niches provide localized signaling molecules to promote stem cell fate and to suppress differentiation. However,in males there is evidence that the stem cell niche forms during the last. The stability of the niche function is of great importance in regulating stem cell behaviour, replaceability and competition among stem cells. The Drosophila adult testis is a long,. The germline stem cell niche of the Drosophila ovary has been a long-standing model for the analysis of the interactions between stem cells and niche cells. In Drosophila males, the stem cell niche and the germline and somatic stem cells (also known as cyst progenitor cells (CPCs)) are located at the closed anterior apex of each testis. , et al. ECs extend long protrusions. JAK/STAT signaling promotes male germline sexual identity by activating the chromatin factor Phf7, and Sxl acts in female germ cells to block JAK/STAT signaling and preserve female identity. The same work also showed that Wolbachia accumulate at the SSCN in maternally infected flies. Each testis. Their results show that hemocyte-derived CollIV is essential for stem cell niche organization. Sci. The concept of “the stem cell niche” was first proposed in studies of the HSC2 (7); however, in vivo evidence of its existence was first shown in the Drosophila GSC (8–10). The somatic hub cells in testes secrete a signalling ligand, called Unpaired (Upd), to activate the JAK–STAT pathway in the male GSCs, and thus function as a major component of the stem cell niche 7, 8 (Figure 1B). Figure 1: Niches, early-stage germline and somatic gonadal cells in Drosophila male and female gonads. In the germarium of the Drosophila ovary, developing germline cysts are surrounded by a population of somatic escort cells that are known to function as the niche cells for germline. Niche establishment begins in larval stages when terminal filaments (TFs) are formed, but the underlying. Moreover, while both niches uti-The youngest, most anterior end of the ovariole contains two populations of stem cells, the GSC and the somatic escort stem cells (ESC). Stem cells are of the utmost importance for the. The niche region. Developmental dynamics : an official publication of the American Association of Anatomists 235: 2969–2979. , 2013. Conversely, ectopic Jak/Stat activation in support cells induces stem cell tumou rs, implying the presence of a signal relay between the stromal compartment and the stem cell population. The ability of adult stem cells to maintain their “stemness” depends critically on the localized microenvironment, or niche. Niches are often structurally and molecularly complex, with diverse signaling pathways operating in a given niche (). Schematic of the Drosophila ovarian germline stem cell (GSC) niche with genes analyzed. An empty Drosophila stem cell niche reactivates the proliferation of ectopic cells. In particular, discovering that individual Drosophila stem cells turn over regularly, compete for niche occupancy and rapidly differentiate when outside their. Th is newly formed cystoblast undergoes four incomplete mitotic divisions to form an interconnected 16-cell cyst. The stem cell niche is a key component of the gonad that provides signals to regulate the germline stem cells (GSCs) necessary for gametogenesis. Each Drosophila ovary is comprised of ovarioles or strings of progressively more developed egg chambers (Fig. Although niches are important to maintain “stemness” in a wide variety of tissues, control of these niches is poorly understood. Bmp signals from niche cells directly repress transcription of the differentiation-promoting gene, bag of marbles, in germline stem cells in the Drosophila ovary. JAK-STAT signaling is a highly conserved regulator of stem cells and their niches. Adult stem cells, which are usually more restricted in their potency to produce different lineages, promise great therapeutic potential after initial clinical applications. one daughter stem cell that remains associated with the cap cell niche and a second daughter that is displaced away from the niche and as a result diff erentiates. Development 140: 4490–4498. Díaz-Torres et al. Among the best-characterized niches are those in the Drosophila gonads, in which germline and somatic stem cells cooperate during gametogenesis (3, 4). FSCs. In Drosophila ovary, niche is composed of somatic cells, including terminal filament cells (TFCs), cap cells (CCs) and escort cells (ECs), which provide extrinsic signals to maintain stem cell. 19 We report that niche architecture in the developing gonad requires trol, that niche cells secrete an isoform-specific Perlecan-rich interstitial matrix,The Drosophila ovariole tip produces new ovarian follicles on a 12-hour cycle by controlling niche-based germline and follicle stem cell divisions and nurturing their developing daughters. Germline stem cell (GSC) self-renewal and differentiation into gametes is regulated by both intrinsic factors in the germ line as well as extrinsic factors from the surrounding somatic niche. find that “companion” hemocytes associate with the Drosophila female gonad to secrete CollIV present in the adult stem cell niche. Here we demonstrate that removal of the Jak/Stat pathway in support cells of the Drosophilaovarian niche leads to germline. germ-line stem cells (GSCs) and escort stem cells, located at the anterior tip of the germarium, and somatic stem cells (SSCs), located adjacent to the newly formed 16-cell cysts. The GSCs and cap cells also contact the Escort stem cells (blue). Crossref;. In Drosophila, a subset of germ cells in both males and females become germline stem cells (GSCs) and populate a stem cell niche created by specific somatic cells. In Drosophila ovary, Dpp is secreted from germline stem cell (GSC) niche and activates the BMP signaling in GSCs for their self-renewal. This review will focus on the roles of JAK-STAT activity. (2017). However, the underlying mechanism for the development of stem cell niche remains largely unclear. The GSC is surrounded by escort stem cells (ESCs) or cyst progenitor stem cells (CPCs) whose daughters (light blue) encyst the GSC daughter cell (pink). In the germarium of the Drosophila ovary, developing germline cysts are surrounded by a population of somatic escort cells that are known to function as the. . The germline stem cell niche, comprised of anterior escort cells and cap cells, secretes Dpp ligand to promote Dpp signaling in the germline stem cells to maintain their stemness. Over the years, Drosophila has served as a wonderful genetically tractable model system to unravel various facets of tissue-resident stem cells in their microenvironment. Each Drosophila ovariole has three independent sets of stem cells: germline stem cells (GSCs) and escort stem cells (ESCs), located at the anterior tip of the germarium, and somatic stem cells (SSCs), located adjacent to the newly formed 16. In the germarium of the Drosophila ovary, developing germline cysts are surrounded by a population of somatic escort cells that are known to function as the niche cells for germline differentiation; 1 however, the underlying molecular mechanisms of this niche function remain poorly understood. elegans and Drosophila stem cell niches ( a ) C.