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Sample records for drosophila embryonic gut

  1. The bHLH transcription factor Hand is regulated by Alk in the Drosophila embryonic gut

    SciTech Connect

    Varshney, Gaurav K.; Palmer, Ruth H. . E-mail: Ruth.Palmer@ucmp.umu.se

    2006-12-29

    During embryonic development the midgut visceral muscle is formed by fusion of cells within the visceral mesoderm, a process initiated by the specification of a specialised cell type, the founder cell, within this tissue. Activation of the receptor tyrosine kinase Anaplastic lymphoma kinase (Alk) in the developing visceral muscle of Drosophila melanogaster initiates a signal transduction pathway required for muscle fusion. In this paper, we have investigated downstream components which are regulated by this novel signalling pathway. Here we show that Alk-mediated signal transduction drives the expression of the bHLH transcription factor Hand in vivo. Loss of Alk function results in a complete lack of Hand expression in this tissue, whereas Alk gain of function results in an expansion of Hand expression. Finally, we have investigated the process of muscle fusion in the gut of Hand mutant animals and can find no obvious defects in this process, suggesting that Hand is not critical for visceral muscle fusion per se.

  2. Rapamycin preserves gut homeostasis during Drosophila aging.

    PubMed

    Fan, Xiaolan; Liang, Qing; Lian, Ting; Wu, Qi; Gaur, Uma; Li, Diyan; Yang, Deying; Mao, Xueping; Jin, Zhihua; Li, Ying; Yang, Mingyao

    2015-11-01

    Gut homeostasis plays an important role in maintaining the overall body health during aging. Rapamycin, a specific inhibitor of mTOR, exerts prolongevity effects in evolutionarily diverse species. However, its impact on the intestinal homeostasis remains poorly understood. Here, we demonstrate that rapamycin can slow down the proliferation rate of intestinal stem cells (ISCs) in the aging guts and induce autophagy in the intestinal epithelium in Drosophila. Rapamycin can also significantly affect the FOXO associated genes in intestine and up-regulate the negative regulators of IMD/Rel pathway, consequently delaying the microbial expansion in the aging guts. Collectively, these findings reveal that rapamycin can delay the intestinal aging by inhibiting mTOR and thus keeping stem cell proliferation in check. These results will further explain the mechanism of healthspan and lifespan extension by rapamycin in Drosophila. PMID:26431326

  3. Rapamycin preserves gut homeostasis during Drosophila aging

    PubMed Central

    Lian, Ting; Wu, Qi; Gaur, Uma; Li, Diyan; Yang, Deying; Mao, Xueping; Jin, Zhihua; Li, Ying; Yang, Mingyao

    2015-01-01

    Gut homeostasis plays an important role in maintaining the overall body health during aging. Rapamycin, a specific inhibitor of mTOR, exerts prolongevity effects in evolutionarily diverse species. However, its impact on the intestinal homeostasis remains poorly understood. Here, we demonstrate that rapamycin can slow down the proliferation rate of intestinal stem cells (ISCs) in the aging guts and induce autophagy in the intestinal epithelium in Drosophila. Rapamycin can also significantly affect the FOXO associated genes in intestine and up-regulate the negative regulators of IMD/Rel pathway, consequently delaying the microbial expansion in the aging guts. Collectively, these findings reveal that rapamycin can delay the intestinal aging by inhibiting mTOR and thus keeping stem cell proliferation in check. These results will further explain the mechanism of healthspan and lifespan extension by rapamycin in Drosophila. PMID:26431326

  4. Gut-associated microbes of Drosophila melanogaster

    PubMed Central

    Broderick, Nichole; Lemaitre, Bruno

    2012-01-01

    There is growing interest in using Drosophila melanogaster to elucidate mechanisms that underlie the complex relationships between a host and its microbiota. In addition to the many genetic resources and tools Drosophila provides, its associated microbiota is relatively simple (1–30 taxa), in contrast to the complex diversity associated with vertebrates (> 500 taxa). These attributes highlight the potential of this system to dissect the complex cellular and molecular interactions that occur between a host and its microbiota. In this review, we summarize what is known regarding the composition of gut-associated microbes of Drosophila and their impact on host physiology. We also discuss these interactions in the context of their natural history and ecology and describe some recent insights into mechanisms by which Drosophila and its gut microbiota interact. “Workers with Drosophila have been considered fortunate in that they deal with the first multicellular invertebrate to be cultured monoxenically (Delcourt and Guyenot, 1910); the first to be handled axenically on a semisynthetic diet (Guyenot, 1917); and the first to be grown on a defined diet (Schultz et al., 1946). This list of advantages is somewhat embarrassing, since it implies an interest in nutrition that, in reality, was only secondary. The very first studies were concerned with the reduction of variability in genetic experiments (Delcourt and Guyenot, 1910) and standardization of the nutritional environment.” -James Sang, 1959 Ann NY Acad 1 PMID:22572876

  5. big bang gene modulates gut immune tolerance in Drosophila.

    PubMed

    Bonnay, François; Cohen-Berros, Eva; Hoffmann, Martine; Kim, Sabrina Y; Boulianne, Gabrielle L; Hoffmann, Jules A; Matt, Nicolas; Reichhart, Jean-Marc

    2013-02-19

    Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases. PMID:23378635

  6. Role of DUOX in gut inflammation: lessons from Drosophila model of gut-microbiota interactions

    PubMed Central

    Kim, Sung-Hee; Lee, Won-Jae

    2013-01-01

    It is well-known that certain bacterial species can colonize the gut epithelium and induce inflammation in the mucosa, whereas other species are either benign or beneficial to the host. Deregulation of the gut-microbe interactions may lead to a pathogenic condition in the host, such as chronic inflammation, tissue injuries, and even cancer. However, our current understanding of the molecular mechanisms that underlie gut-microbe homeostasis and pathogenesis remains limited. Recent studies have used Drosophila as a genetic model to provide novel insights into the causes and consequences of bacterial-induced colitis in the intestinal mucosa. The present review discusses the interactions that occur between gut-associated bacteria and host gut immunity, particularly the bacterial-induced intestinal dual oxidase (DUOX) system. Several lines of evidence showed that the bacterial-modulated DUOX system is involved in microbial clearance, intestinal epithelial cell renewal (ECR), redox-dependent modulation of signaling pathways, cross-linking of biomolecules, and discrimination between symbionts and pathogens. Further genetic studies on the Drosophila DUOX system and on gut-associated bacteria with a distinct ability to activate DUOX may provide critical information related to the homeostatic inflammation as well as etiology of chronic inflammatory diseases, which will enhance our understanding on the mucosal inflammatory diseases frequently observed in the microbe-contacting epithelia of humans. PMID:24455491

  7. Bacteria sensing mechanisms in Drosophila gut: Local and systemic consequences.

    PubMed

    Capo, Florence; Charroux, Bernard; Royet, Julien

    2016-11-01

    All insects are colonized by microorganisms on their exoskeleton, their gut and even in some cases within their own somatic and germ line cells. This microbiota that can represent up to a few percent of the insect biomass may have a pervasive impact on many aspects of insect biology including physiology, nutrient acquisition, ageing, behaviour and resistance to infection. Mainly through ingestion of contaminated food, the mouth-gut axis represents the first and principal access of external bacteria to the host. Soon after ingestion, the feeding insect needs to rapidly and accurately identify the ingested microbes and decide whether to preserve them if beneficial or neutral, or to eliminate them if potentially harmful. We will review here the recent data acquired in Drosophila on the mechanisms that invertebrate enterocytes rely on to detect the presence of bacteria in the gut. We will compare these modes of bacteria sensing to those in other immune competent tissues and try to rationalize differences that may exist. We will also analyse the physiological consequences of bacteria detection not only locally for the gut itself but also for remote tissues. Finally, we will describe the physiological disorders that can occur due to inaccurate bacteria identification by the gut epithelium. PMID:26778296

  8. Gut microbiota dictates the metabolic response of Drosophila to diet

    PubMed Central

    Wong, Adam C.-N.; Dobson, Adam J.; Douglas, Angela E.

    2014-01-01

    Animal nutrition is profoundly influenced by the gut microbiota, but knowledge of the scope and core mechanisms of the underlying animal–microbiota interactions is fragmentary. To investigate the nutritional traits shaped by the gut microbiota of Drosophila, we determined the microbiota-dependent response of multiple metabolic and performance indices to systematically varied diet composition. Diet-dependent differences between Drosophila bearing its unmanipulated microbiota (conventional flies) and experimentally deprived of its microbiota (axenic flies) revealed evidence for: microbial sparing of dietary B vitamins, especially riboflavin, on low-yeast diets; microbial promotion of protein nutrition, particularly in females; and microbiota-mediated suppression of lipid/carbohydrate storage, especially on high sugar diets. The microbiota also sets the relationship between energy storage and body mass, indicative of microbial modulation of the host signaling networks that coordinate metabolism with body size. This analysis identifies the multiple impacts of the microbiota on the metabolism of Drosophila, and demonstrates that the significance of these different interactions varies with diet composition and host sex. PMID:24577449

  9. Exploring interactions between pathogens and the Drosophila gut.

    PubMed

    Mistry, Rupal; Kounatidis, Ilias; Ligoxygakis, Petros

    2016-11-01

    Gastrointestinal infection can provoke substantial disturbance at both a local as well as at a systemic level and may evolve into a chronic disease state. Our growing knowledge of gut-pathogen interactions has been based to a large extent on the use of genetically tractable model hosts such as the fruit fly Drosophila melanogaster. In this review we will summarise the growing literature and critically address the advantages and disadvantages of using this model to extrapolate results from studying pathogen virulence and intestinal responses to humans. PMID:26876781

  10. Embryonic multipotent progenitors remodel the Drosophila airways during metamorphosis

    PubMed Central

    Pitsouli, Chrysoula; Perrimon, Norbert

    2010-01-01

    Adult structures in holometabolous insects such as Drosophila are generated by groups of imaginal cells dedicated to the formation of different organs. Imaginal cells are specified in the embryo and remain quiescent until the larval stages, when they proliferate and differentiate to form organs. The Drosophila tracheal system is extensively remodeled during metamorphosis by a small number of airway progenitors. Among these, the spiracular branch tracheoblasts are responsible for the generation of the pupal and adult abdominal airways. To understand the coordination of proliferation and differentiation during organogenesis of tubular organs, we analyzed the remodeling of Drosophila airways during metamorphosis. We show that the embryonic spiracular branch tracheoblasts are multipotent cells that express the homeobox transcription factor Cut, which is necessary for their survival and normal development. They give rise to three distinct cell populations at the end of larval development, which generate the adult tracheal tubes, the spiracle and the epidermis surrounding the spiracle. Our study establishes the series of events that lead to the formation of an adult tubular structure in Drosophila. PMID:20940225

  11. A role for Phospholipase D in Drosophila embryonic cellularization

    PubMed Central

    LaLonde, Mary; Janssens, Hilde; Yun, Suyong; Crosby, Juan; Redina, Olga; Olive, Virginie; Altshuller, Yelena M; Choi, Seok-Yong; Du, Guangwei; Gergen, J Peter; Frohman, Michael A

    2006-01-01

    Background Cellularization of the Drosophila embryo is an unusually synchronous form of cytokinesis in which polarized membrane extension proceeds in part through incorporation of new membrane via fusion of apically-translocated Golgi-derived vesicles. Results We describe here involvement of the signaling enzyme Phospholipase D (Pld) in regulation of this developmental step. Functional analysis using gene targeting revealed that cellularization is hindered by the loss of Pld, resulting frequently in early embryonic developmental arrest. Mechanistically, chronic Pld deficiency causes abnormal Golgi structure and secretory vesicle trafficking. Conclusion Our results suggest that Pld functions to promote trafficking of Golgi-derived fusion-competent vesicles during cellularization. PMID:17156430

  12. Kin recognition in Drosophila: the importance of ecology and gut microbiota

    PubMed Central

    Lizé, Anne; McKay, Raegan; Lewis, Zenobia

    2014-01-01

    The animal gut commonly contains a large reservoir of symbiotic microbes. Although these microbes have obvious functions in digestion and immune defence, gut microbes can also affect behaviour. Here, we explore whether gut microbiota has a role in kin recognition. We assessed whether relatedness, familiarity and food eaten during development altered copulation investment in three species of Drosophila with diverse ecologies. We found that a monandrous species exhibited true kin recognition, whereas familiarity determined kin recognition in a species living in dense aggregations. Finally, in a food generalist species, food eaten during development masked kin recognition. The effect of food type on copulation duration, in addition to the removal of this effect via antibiotic treatment, suggests the influence of bacteria associated with the gut. Our results provide the first evidence that varied ecologically determined mechanisms of kin recognition occur in Drosophila, and that gut bacteria are likely to have a key role in these mechanisms. PMID:24030598

  13. The inconstant gut microbiota of Drosophila species revealed by 16S rRNA gene analysis

    PubMed Central

    Wong, Adam C-N; Chaston, John M; Douglas, Angela E

    2013-01-01

    The gut microorganisms in some animals are reported to include a core microbiota of consistently associated bacteria that is ecologically distinctive and may have coevolved with the host. The core microbiota is promoted by positive interactions among bacteria, favoring shared persistence; its retention over evolutionary timescales is evident as congruence between host phylogeny and bacterial community composition. This study applied multiple analyses to investigate variation in the composition of gut microbiota in drosophilid flies. First, the prevalence of five previously described gut bacteria (Acetobacter and Lactobacillus species) in individual flies of 21 strains (10 Drosophila species) were determined. Most bacteria were not present in all individuals of most strains, and bacterial species pairs co-occurred in individual flies less frequently than predicted by chance, contrary to expectations of a core microbiota. A complementary pyrosequencing analysis of 16S rRNA gene amplicons from the gut microbiota of 11 Drosophila species identified 209 bacterial operational taxonomic units (OTUs), with near-saturating sampling of sequences, but none of the OTUs was common to all host species. Furthermore, in both of two independent sets of Drosophila species, the gut bacterial community composition was not congruent with host phylogeny. The final analysis identified no common OTUs across three wild and four laboratory samples of D. melanogaster. Our results yielded no consistent evidence for a core microbiota in Drosophila. We conclude that the taxonomic composition of gut microbiota varies widely within and among Drosophila populations and species. This is reminiscent of the patterns of bacterial composition in guts of some other animals, including humans. PMID:23719154

  14. The inconstant gut microbiota of Drosophila species revealed by 16S rRNA gene analysis.

    PubMed

    Wong, Adam C-N; Chaston, John M; Douglas, Angela E

    2013-10-01

    The gut microorganisms in some animals are reported to include a core microbiota of consistently associated bacteria that is ecologically distinctive and may have coevolved with the host. The core microbiota is promoted by positive interactions among bacteria, favoring shared persistence; its retention over evolutionary timescales is evident as congruence between host phylogeny and bacterial community composition. This study applied multiple analyses to investigate variation in the composition of gut microbiota in drosophilid flies. First, the prevalence of five previously described gut bacteria (Acetobacter and Lactobacillus species) in individual flies of 21 strains (10 Drosophila species) were determined. Most bacteria were not present in all individuals of most strains, and bacterial species pairs co-occurred in individual flies less frequently than predicted by chance, contrary to expectations of a core microbiota. A complementary pyrosequencing analysis of 16S rRNA gene amplicons from the gut microbiota of 11 Drosophila species identified 209 bacterial operational taxonomic units (OTUs), with near-saturating sampling of sequences, but none of the OTUs was common to all host species. Furthermore, in both of two independent sets of Drosophila species, the gut bacterial community composition was not congruent with host phylogeny. The final analysis identified no common OTUs across three wild and four laboratory samples of D. melanogaster. Our results yielded no consistent evidence for a core microbiota in Drosophila. We conclude that the taxonomic composition of gut microbiota varies widely within and among Drosophila populations and species. This is reminiscent of the patterns of bacterial composition in guts of some other animals, including humans. PMID:23719154

  15. Identification and Characterization of Genes Involved in Embryonic Crystal Cell Formation During Drosophila Hematopoiesis

    PubMed Central

    Milchanowski, Allison B.; Henkenius, Amy L.; Narayanan, Maya; Hartenstein, Volker; Banerjee, Utpal

    2004-01-01

    Parallels between vertebrate and Drosophila hematopoiesis add to the value of flies as a model organism to gain insights into blood development. The Drosophila hematopoietic system is composed of at least three classes of terminally differentiated blood cells: plasmatocytes, crystal cells, and lamellocytes. Recent studies have identified transcriptional and signaling pathways in Drosophila involving proteins similar to those seen in human blood development. To identify additional genes involved in Drosophila hematopoiesis, we have conducted a P-element-based genetic screen to isolate mutations that affect embryonic crystal cell development. Using a marker of terminally differentiated crystal cells, we screened 1040 P-element-lethal lines located on the second and third chromosomes and identified 44 individual lines that affect crystal cell development. Identifying novel genes and pathways involved in Drosophila hematopoiesis is likely to provide further insights into mammalian hematopoietic development and disorders. PMID:15454546

  16. The mechanical properties of Drosophila jump muscle expressing wild-type and embryonic Myosin isoforms.

    PubMed

    Eldred, Catherine C; Simeonov, Dimitre R; Koppes, Ryan A; Yang, Chaoxing; Corr, David T; Swank, Douglas M

    2010-04-01

    Transgenic Drosophila are highly useful for structure-function studies of muscle proteins. However, our ability to mechanically analyze transgenically expressed mutant proteins in Drosophila muscles has been limited to the skinned indirect flight muscle preparation. We have developed a new muscle preparation using the Drosophila tergal depressor of the trochanter (TDT or jump) muscle that increases our experimental repertoire to include maximum shortening velocity (V(slack)), force-velocity curves and steady-state power generation; experiments not possible using indirect flight muscle fibers. When transgenically expressing its wild-type myosin isoform (Tr-WT) the TDT is equivalent to a very fast vertebrate muscle. TDT has a V(slack) equal to 6.1 +/- 0.3 ML/s at 15 degrees C, a steep tension-pCa curve, isometric tension of 37 +/- 3 mN/mm(2), and maximum power production at 26% of isometric tension. Transgenically expressing an embryonic myosin isoform in the TDT muscle increased isometric tension 1.4-fold, but decreased V(slack) 50% resulting in no significant difference in maximum power production compared to Tr-WT. Drosophila expressing embryonic myosin jumped <50% as far as Tr-WT that, along with comparisons to frog jump muscle studies, suggests fast muscle shortening velocity is relatively more important than high tension generation for Drosophila jumping. PMID:20371321

  17. Impact of the Chromatin Remodeling Factor CHD1 on Gut Microbiome Composition of Drosophila melanogaster

    PubMed Central

    Krogsdam, Anne; Orth-Höller, Dorothea; Trajanoski, Zlatko; Lusser, Alexandra

    2016-01-01

    The composition of the intestinal microbiota of Drosophila has been studied in some detail in recent years. Environmental, developmental and host-specific genetic factors influence microbiome composition in the fly. Our previous work has indicated that intestinal bacterial load can be affected by chromatin-targeted regulatory mechanisms. Here we studied a potential role of the conserved chromatin assembly and remodeling factor CHD1 in the shaping of the gut microbiome in Drosophila melanogaster. Using high-throughput sequencing of 16S rRNA gene amplicons, we found that Chd1 deletion mutant flies exhibit significantly reduced microbial diversity compared to rescued control strains. Specifically, although Acetobacteraceae dominated the microbiota of both Chd1 wild-type and mutant guts, Chd1 mutants were virtually monoassociated with this bacterial family, whereas in control flies other bacterial taxa constituted ~20% of the microbiome. We further show age-linked differences in microbial load and microbiota composition between Chd1 mutant and control flies. Finally, diet supplementation experiments with Lactobacillus plantarum revealed that, in contrast to wild-type flies, Chd1 mutant flies were unable to maintain higher L. plantarum titres over time. Collectively, these data provide evidence that loss of the chromatin remodeler CHD1 has a major impact on the gut microbiome of Drosophila melanogaster. PMID:27093431

  18. Impact of the Chromatin Remodeling Factor CHD1 on Gut Microbiome Composition of Drosophila melanogaster.

    PubMed

    Sebald, Johanna; Willi, Michaela; Schoberleitner, Ines; Krogsdam, Anne; Orth-Höller, Dorothea; Trajanoski, Zlatko; Lusser, Alexandra

    2016-01-01

    The composition of the intestinal microbiota of Drosophila has been studied in some detail in recent years. Environmental, developmental and host-specific genetic factors influence microbiome composition in the fly. Our previous work has indicated that intestinal bacterial load can be affected by chromatin-targeted regulatory mechanisms. Here we studied a potential role of the conserved chromatin assembly and remodeling factor CHD1 in the shaping of the gut microbiome in Drosophila melanogaster. Using high-throughput sequencing of 16S rRNA gene amplicons, we found that Chd1 deletion mutant flies exhibit significantly reduced microbial diversity compared to rescued control strains. Specifically, although Acetobacteraceae dominated the microbiota of both Chd1 wild-type and mutant guts, Chd1 mutants were virtually monoassociated with this bacterial family, whereas in control flies other bacterial taxa constituted ~20% of the microbiome. We further show age-linked differences in microbial load and microbiota composition between Chd1 mutant and control flies. Finally, diet supplementation experiments with Lactobacillus plantarum revealed that, in contrast to wild-type flies, Chd1 mutant flies were unable to maintain higher L. plantarum titres over time. Collectively, these data provide evidence that loss of the chromatin remodeler CHD1 has a major impact on the gut microbiome of Drosophila melanogaster. PMID:27093431

  19. Genetic, molecular and physiological basis of variation in Drosophila gut immunocompetence

    PubMed Central

    Bou Sleiman, Maroun S.; Osman, Dani; Massouras, Andreas; Hoffmann, Ary A.; Lemaitre, Bruno; Deplancke, Bart

    2015-01-01

    Gut immunocompetence involves immune, stress and regenerative processes. To investigate the determinants underlying inter-individual variation in gut immunocompetence, we perform enteric infection of 140 Drosophila lines with the entomopathogenic bacterium Pseudomonas entomophila and observe extensive variation in survival. Using genome-wide association analysis, we identify several novel immune modulators. Transcriptional profiling further shows that the intestinal molecular state differs between resistant and susceptible lines, already before infection, with one transcriptional module involving genes linked to reactive oxygen species (ROS) metabolism contributing to this difference. This genetic and molecular variation is physiologically manifested in lower ROS activity, lower susceptibility to ROS-inducing agent, faster pathogen clearance and higher stem cell activity in resistant versus susceptible lines. This study provides novel insights into the determinants underlying population-level variability in gut immunocompetence, revealing how relatively minor, but systematic genetic and transcriptional variation can mediate overt physiological differences that determine enteric infection susceptibility. PMID:26213329

  20. Host-microbe interactions in the gut of Drosophila melanogaster

    PubMed Central

    Kuraishi, Takayuki; Hori, Aki; Kurata, Shoichiro

    2013-01-01

    Many insect species subsist on decaying and contaminated matter and are thus exposed to large quantities of microorganisms. To control beneficial commensals and combat infectious pathogens, insects must be armed with efficient systems for microbial recognition, signaling pathways, and effector molecules. The molecular mechanisms regulating these host-microbe interactions in insects have been largely clarified in Drosophila melanogaster with its powerful genetic and genomic tools. Here we review recent advances in this field, focusing mainly on the relationships between microbes and epithelial cells in the intestinal tract where the host exposure to the external environment is most frequent. PMID:24381562

  1. Drosophila EGFR pathway coordinates stem cell proliferation and gut remodeling following infection

    PubMed Central

    2010-01-01

    Background Gut homeostasis is central to whole organism health, and its disruption is associated with a broad range of pathologies. Following damage, complex physiological events are required in the gut to maintain proper homeostasis. Previously, we demonstrated that ingestion of a nonlethal pathogen, Erwinia carotovora carotovora 15, induces a massive increase in stem cell proliferation in the gut of Drosophila. However, the precise cellular events that occur following infection have not been quantitatively described, nor do we understand the interaction between multiple pathways that have been implicated in epithelium renewal. Results To understand the process of infection and epithelium renewal in more detail, we performed a quantitative analysis of several cellular and morphological characteristics of the gut. We observed that the gut of adult Drosophila undergoes a dynamic remodeling in response to bacterial infection. This remodeling coordinates the synthesis of new enterocytes, their proper morphogenesis and the elimination of damaged cells through delamination and anoikis. We demonstrate that one signaling pathway, the epidermal growth factor receptor (EGFR) pathway, is key to controlling each of these steps through distinct functions in intestinal stem cells and enterocytes. The EGFR pathway is activated by the EGF ligands, Spitz, Keren and Vein, the latter being induced in the surrounding visceral muscles in part under the control of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. Additionally, the EGFR pathway synergizes with the JAK/STAT pathway in stem cells to promote their proliferation. Finally, we show that the EGFR pathway contributes to gut morphogenesis through its activity in enterocytes and is required to properly coordinate the delamination and anoikis of damaged cells. This function of the EGFR pathway in enterocytes is key to maintaining homeostasis, as flies lacking EGFR are highly susceptible to

  2. The Host as the Driver of the Microbiota in the Gut and External Environment of Drosophila melanogaster

    PubMed Central

    Wong, Adam C.-N.; Luo, Yuan; Jing, Xiangfeng; Franzenburg, Soeren; Bost, Alyssa

    2015-01-01

    Most associations between animals and their gut microbiota are dynamic, involving sustained transfer of food-associated microbial cells into the gut and shedding of microorganisms into the external environment with feces, but the interacting effects of host and microbial factors on the composition of the internal and external microbial communities are poorly understood. This study on laboratory cultures of the fruit fly Drosophila melanogaster reared in continuous contact with their food revealed time-dependent changes of the microbial communities in the food that were strongly influenced by the presence and abundance of Drosophila. When germfree Drosophila eggs were aseptically added to nonsterile food, the microbiota in the food and flies converged to a composition dramatically different from that in fly-free food, showing that Drosophila has microbiota-independent effects on the food microbiota. The microbiota in both the flies that developed from unmanipulated eggs (bearing microorganisms) and the associated food was dominated by the bacteria most abundant on the eggs, demonstrating effective vertical transmission via surface contamination of eggs. Food coinoculated with a four-species defined bacterial community of Acetobacter and Lactobacillus species revealed the progressive elimination of Lactobacillus from the food bearing few or no Drosophila, indicating the presence of antagonistic interactions between Acetobacter and Lactobacillus. Drosophila at high densities ameliorated the Acetobacter/Lactobacillus antagonism, enabling Lactobacillus to persist. This study with Drosophila demonstrates how animals can have major, coordinated effects on the composition of microbial communities in the gut and immediate environment. PMID:26150460

  3. The Host as the Driver of the Microbiota in the Gut and External Environment of Drosophila melanogaster.

    PubMed

    Wong, Adam C-N; Luo, Yuan; Jing, Xiangfeng; Franzenburg, Soeren; Bost, Alyssa; Douglas, Angela E

    2015-09-01

    Most associations between animals and their gut microbiota are dynamic, involving sustained transfer of food-associated microbial cells into the gut and shedding of microorganisms into the external environment with feces, but the interacting effects of host and microbial factors on the composition of the internal and external microbial communities are poorly understood. This study on laboratory cultures of the fruit fly Drosophila melanogaster reared in continuous contact with their food revealed time-dependent changes of the microbial communities in the food that were strongly influenced by the presence and abundance of Drosophila. When germfree Drosophila eggs were aseptically added to nonsterile food, the microbiota in the food and flies converged to a composition dramatically different from that in fly-free food, showing that Drosophila has microbiota-independent effects on the food microbiota. The microbiota in both the flies that developed from unmanipulated eggs (bearing microorganisms) and the associated food was dominated by the bacteria most abundant on the eggs, demonstrating effective vertical transmission via surface contamination of eggs. Food coinoculated with a four-species defined bacterial community of Acetobacter and Lactobacillus species revealed the progressive elimination of Lactobacillus from the food bearing few or no Drosophila, indicating the presence of antagonistic interactions between Acetobacter and Lactobacillus. Drosophila at high densities ameliorated the Acetobacter/Lactobacillus antagonism, enabling Lactobacillus to persist. This study with Drosophila demonstrates how animals can have major, coordinated effects on the composition of microbial communities in the gut and immediate environment. PMID:26150460

  4. The Dmca1D channel mediates Ca(2+) inward currents in Drosophila embryonic muscles.

    PubMed

    Hara, Yusuke; Koganezawa, Masayuki; Yamamoto, Daisuke

    2015-01-01

    We studied, in a genetic model organism, Drosophila melanogaster, the channel mechanisms underlying membrane excitation in the embryonic body wall muscle whose biophysical properties have been poorly characterized. The inward current underlying the action potential was solely mediated by a high-threshold class of voltage-gated Ca(2+) channels, which exhibited slow inactivation, Ca(2+) permeability with saturation at high [Ca(2+)]OUT, and sensitivity to a Ca(2+) channel blocker, Cd(2+). The Ca(2+) current in the embryonic muscle was completely eliminated in Dmca1D mutants, indicating that the Dmca1D-encoded Ca(2+) channel is the major mediator of inward currents in the body wall muscles throughout the embryonic and larval stages. PMID:26004544

  5. From pathogens to microbiota: How Drosophila intestinal stem cells react to gut microbes.

    PubMed

    Bonfini, Alessandro; Liu, Xi; Buchon, Nicolas

    2016-11-01

    The intestine acts as one of the interfaces between an organism and its external environment. As the primary digestive organ, it is constantly exposed to a multitude of stresses as it processes and absorbs nutrients. Among these is the recurring damage induced by ingested pathogenic and commensal microorganisms. Both the bacterial activity and immune response itself can result in the loss of epithelial cells, which subsequently requires replacement. In the Drosophila midgut, this regenerative role is fulfilled by intestinal stem cells (ISCs). Microbes not only trigger cell loss and replacement, but also modify intestinal and whole organism physiology, thus modulating ISC activity. Regulation of ISCs is integrated through a complex network of signaling pathways initiated by other gut cell populations, including enterocytes, enteroblasts, enteroendocrine and visceral muscles cells. The gut also receives signals from circulating immune cells, the hemocytes, to properly respond against infection. This review summarizes the types of gut microbes found in Drosophila, mechanisms for their elimination, and provides an integrated view of the signaling pathways that regulate tissue renewal in the midgut. PMID:26855015

  6. Effects of the isoflavone prunetin on gut health and stress response in male Drosophila melanogaster

    PubMed Central

    Piegholdt, Stefanie; Rimbach, Gerald; Wagner, Anika E.

    2016-01-01

    The traditional Asian diet is rich in fruits, vegetables and soy, the latter representing a significant source of dietary isoflavones. The isoflavone prunetin was recently identified to improve intestinal epithelial barrier function in vitro and to ameliorate general survival and overall health state in vivo in male Drosophila melanogaster. However, the prunetin-mediated health benefits in the fruit fly were ascertained under standard living conditions. As the loss of intestinal integrity is closely related to a reduction in Drosophila lifespan and barrier dysfunction increases with age, effects on prunetin-modulated gut health under oxidative or pathogenic stress provocation remain to be elucidated. In this study, male adult D. melanogaster were administered either a prunetin or a control diet. Gut-derived junction protein expression and pathogen-induced antimicrobial peptide expressions as well as the stem cell proliferation in the gut were evaluated. Furthermore, survival following exposure to hydrogen peroxide was assessed. Prunetin ingestion did not attenuate bacterial infection and did not protect flies from oxidative stress. Intestinal mRNA expression levels of adherence and septate junction proteins as well as the stem cell proliferation were not altered by prunetin intake. Prunetin does not improve the resistance of flies against severe injuring, exogenous stress and therefore seems to function in a preventive rather than a therapeutic approach since the health-promoting benefits appear to be exclusively restricted to normal living circumstances. PMID:26774080

  7. Effects of the isoflavone prunetin on gut health and stress response in male Drosophila melanogaster.

    PubMed

    Piegholdt, Stefanie; Rimbach, Gerald; Wagner, Anika E

    2016-08-01

    The traditional Asian diet is rich in fruits, vegetables and soy, the latter representing a significant source of dietary isoflavones. The isoflavone prunetin was recently identified to improve intestinal epithelial barrier function in vitro and to ameliorate general survival and overall health state in vivo in male Drosophila melanogaster. However, the prunetin-mediated health benefits in the fruit fly were ascertained under standard living conditions. As the loss of intestinal integrity is closely related to a reduction in Drosophila lifespan and barrier dysfunction increases with age, effects on prunetin-modulated gut health under oxidative or pathogenic stress provocation remain to be elucidated. In this study, male adult D. melanogaster were administered either a prunetin or a control diet. Gut-derived junction protein expression and pathogen-induced antimicrobial peptide expressions as well as the stem cell proliferation in the gut were evaluated. Furthermore, survival following exposure to hydrogen peroxide was assessed. Prunetin ingestion did not attenuate bacterial infection and did not protect flies from oxidative stress. Intestinal mRNA expression levels of adherence and septate junction proteins as well as the stem cell proliferation were not altered by prunetin intake. Prunetin does not improve the resistance of flies against severe injuring, exogenous stress and therefore seems to function in a preventive rather than a therapeutic approach since the health-promoting benefits appear to be exclusively restricted to normal living circumstances. PMID:26774080

  8. Low-diversity bacterial community in the gut of the fruitfly Drosophila melanogaster.

    PubMed

    Wong, Chun Nin Adam; Ng, Patrick; Douglas, Angela E

    2011-07-01

    The bacteria in the fruitfly Drosophila melanogaster of different life stages was quantified by 454 pyrosequencing of 16S rRNA gene amplicons. The sequence reads were dominated by 5 operational taxonomic units (OTUs) at ≤ 97% sequence identity that could be assigned to Acetobacter pomorum, A. tropicalis, Lactobacillus brevis, L. fructivorans and L. plantarum. The saturated rarefaction curves and species richness indices indicated that the sampling (85,000-159,000 reads per sample) was comprehensive. Parallel diagnostic PCR assays revealed only minor variation in the complement of the five bacterial species across individual insects and three D. melanogaster strains. Other gut-associated bacteria included 6 OTUs with low %ID to previously reported sequences, raising the possibility that they represent novel taxa within the genera Acetobacter and Lactobacillus. A developmental change in the most abundant species, from L. fructivorans in young adults to A. pomorum in aged adults was identified; changes in gut oxygen tension or immune system function might account for this effect. Host immune responses and disturbance may also contribute to the low bacterial diversity in the Drosophila gut habitat. PMID:21631690

  9. Cloning, characterization, and embryonic expression analysis of the Drosophila melanogaster gene encoding insulin/relaxin-like peptide.

    PubMed

    Nasonkin, Igor O; Alikasifoglu, Ayfer; Barrette, Terry; Cheng, Michael M; Thomas, Pamela M; Nikitin, Alexey G

    2002-07-12

    Insulin is one of the key peptide hormones that regulates growth and metabolism in vertebrates. Evolutionary conservation of many elements of the insulin/IGF signaling network makes it possible to study the basic genetic function of this pathway in lower metazoan models such as Drosophila. Here we report the cloning and characterization of the gene for Drosophila insulin/relaxin-like peptide (DIRLP). The predicted protein structure of DIRLP greatly resembles typical insulin structure and contains features that differentiate it from the Drosophila juvenile hormone, another member of the insulin family. The Dirlp gene is represented as a single copy in the Drosophila melanogaster genome (compared to multiple copies for Drosophila juvenile hormone) and shows evolutionary conservation of genetic structure. The gene was mapped to the Drosophila chromosome 3, region 67D2. In situ hybridization of whole-mount Drosophila embryos with Dirlp antisense RNA probe reveals early embryonic mesodermal/ventral furrow expression pattern, consistent with earlier observation of the insulin protein immunoreactivity in Drosophila embryos. The in situ hybridization pattern was found to be identical to that obtained during immunohistochemistry analysis of the Drosophila embryos using various insulin monoclonal and polyclonal antibodies that do not recognize Drosophila juvenile hormone, supporting the idea that Dirlp is a possible Drosophila insulin ortholog. Identification of the gene for DIRLP provides a new approach for study of the regulatory pathway of the insulin family of peptides. PMID:12150949

  10. Microbiota-Induced Changes in Drosophila melanogaster Host Gene Expression and Gut Morphology

    PubMed Central

    Buchon, Nicolas

    2014-01-01

    ABSTRACT To elucidate mechanisms underlying the complex relationships between a host and its microbiota, we used the genetically tractable model Drosophila melanogaster. Consistent with previous studies, the microbiota was simple in composition and diversity. However, analysis of single flies revealed high interfly variability that correlated with differences in feeding. To understand the effects of this simple and variable consortium, we compared the transcriptome of guts from conventionally reared flies to that for their axenically reared counterparts. Our analysis of two wild-type fly lines identified 121 up- and 31 downregulated genes. The majority of these genes were associated with immune responses, tissue homeostasis, gut physiology, and metabolism. By comparing the transcriptomes of young and old flies, we identified temporally responsive genes and showed that the overall impact of microbiota was greater in older flies. In addition, comparison of wild-type gene expression with that of an immune-deficient line revealed that 53% of upregulated genes exerted their effects through the immune deficiency (Imd) pathway. The genes included not only classic immune response genes but also those involved in signaling, gene expression, and metabolism, unveiling new and unexpected connections between immunity and other systems. Given these findings, we further characterized the effects of gut-associated microbes on gut morphology and epithelial architecture. The results showed that the microbiota affected gut morphology through their impacts on epithelial renewal rate, cellular spacing, and the composition of different cell types in the epithelium. Thus, while bacteria in the gut are highly variable, the influence of the microbiota at large has far-reaching effects on host physiology. PMID:24865556

  11. Spatial expression of transcription factors in Drosophila embryonic organ development

    PubMed Central

    2013-01-01

    Background Site-specific transcription factors (TFs) bind DNA regulatory elements to control expression of target genes, forming the core of gene regulatory networks. Despite decades of research, most studies focus on only a small number of TFs and the roles of many remain unknown. Results We present a systematic characterization of spatiotemporal gene expression patterns for all known or predicted Drosophila TFs throughout embryogenesis, the first such comprehensive study for any metazoan animal. We generated RNA expression patterns for all 708 TFs by in situ hybridization, annotated the patterns using an anatomical controlled vocabulary, and analyzed TF expression in the context of organ system development. Nearly all TFs are expressed during embryogenesis and more than half are specifically expressed in the central nervous system. Compared to other genes, TFs are enriched early in the development of most organ systems, and throughout the development of the nervous system. Of the 535 TFs with spatially restricted expression, 79% are dynamically expressed in multiple organ systems while 21% show single-organ specificity. Of those expressed in multiple organ systems, 77 TFs are restricted to a single organ system either early or late in development. Expression patterns for 354 TFs are characterized for the first time in this study. Conclusions We produced a reference TF dataset for the investigation of gene regulatory networks in embryogenesis, and gained insight into the expression dynamics of the full complement of TFs controlling the development of each organ system. PMID:24359758

  12. Consumption of dietary sugar by gut bacteria determines Drosophila lipid content.

    PubMed

    Huang, Jia-Hsin; Douglas, Angela E

    2015-09-01

    Gut microorganisms are essential for the nutritional health of many animals, but the underlying mechanisms are poorly understood. This study investigated how lipid accumulation by adult Drosophila melanogaster is reduced in flies associated with the bacterium Acetobacter tropicalis which displays oral-faecal cycling between the gut and food. We demonstrate that the lower lipid content of A. tropicalis-colonized flies relative to bacteria-free flies is linked with a parallel bacterial-mediated reduction in food glucose content; and can be accounted for quantitatively by the amount of glucose acquired by the flies, as determined from the feeding rate and assimilation efficiency of bacteria-free and A. tropicalis-colonized flies. We recommend that nutritional studies on Drosophila include empirical quantification of food nutrient content, to account for likely microbial-mediated effects on diet composition. More broadly, this study demonstrates that selective consumption of dietary constituents by microorganisms can alter the nutritional balance of food and, thereby, influence the nutritional status of the animal host. PMID:26382071

  13. Morphological Markers for Cryopreservation in the Embryonic Development of Drosophila suzukii (Diptera: Drosophilidae).

    PubMed

    Landi, Silvia; Gargani, Elisabetta; Paoli, Francesco; Simoni, Sauro; Roversi, Pio Federico

    2015-08-01

    Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an invasive pest recently reported in Europe whose spread into new areas has caused severe economic damage to many agricultural crops. There are serious concerns about the currently available chemical insecticides because of their low efficacy in controlling the species and their environmental impact; so, several studies have focused on environmentally safe strategies. The sterile insect technique (SIT), which requires colony maintenance in laboratory and production of large numbers of live animals, can be utilized in pest management programs and could be integrated with other control strategies if the potential risks associated with the rearing and maintenance of the insect line under laboratory conditions are given sufficient attention. In this regard, the ability to cryobiologically preserve such stocks would be of substantial value. Important prerequisites for long-term cryopreservation are determination of the embryonic stages, identification of specific embryonic stages, and knowledge of development time. This paper describes the main visible markers for the different stages of embryonic development and determines the timing of development at 25°C. D. suzukii embryogenesis lasts 23-25 h at 25°C and can be divided into 17 stages defined by specific morphological markers. The point at which 50% of embryos are at Stage 14 and 50% are at Stage 15, the most tolerant stages for cryopreservation treatment, as ascertained for Drosophila melanogaster Meigen in prior studies, is reached in 14-15 h. The efficiency of this procedure might be impaired by the retention of eggs in the oviducts, making it impossible to determine the stage of embryonic development for ∼25% of laid eggs. PMID:26470330

  14. In vivo function and comparative genomic analyses of the Drosophila gut microbiota identify candidate symbiosis factors

    PubMed Central

    Newell, Peter D.; Chaston, John M.; Wang, Yiping; Winans, Nathan J.; Sannino, David R.; Wong, Adam C. N.; Dobson, Adam J.; Kagle, Jeanne; Douglas, Angela E.

    2014-01-01

    Symbiosis is often characterized by co-evolutionary changes in the genomes of the partners involved. An understanding of these changes can provide insight into the nature of the relationship, including the mechanisms that initiate and maintain an association between organisms. In this study we examined the genome sequences of bacteria isolated from the Drosophila melanogaster gut with the objective of identifying genes that are important for function in the host. We compared microbiota isolates with con-specific or closely related bacterial species isolated from non-fly environments. First the phenotype of germ-free Drosophila (axenic flies) was compared to that of flies colonized with specific bacteria (gnotobiotic flies) as a measure of symbiotic function. Non-fly isolates were functionally distinct from bacteria isolated from flies, conferring slower development and an altered nutrient profile in the host, traits known to be microbiota-dependent. Comparative genomic methods were next employed to identify putative symbiosis factors: genes found in bacteria that restore microbiota-dependent traits to gnotobiotic flies, but absent from those that do not. Factors identified include riboflavin synthesis and stress resistance. We also used a phylogenomic approach to identify protein coding genes for which fly-isolate sequences were more similar to each other than to other sequences, reasoning that these genes may have a shared function unique to the fly environment. This method identified genes in Acetobacter species that cluster in two distinct genomic loci: one predicted to be involved in oxidative stress detoxification and another encoding an efflux pump. In summary, we leveraged genomic and in vivo functional comparisons to identify candidate traits that distinguish symbiotic bacteria. These candidates can serve as the basis for further work investigating the genetic requirements of bacteria for function and persistence in the Drosophila gut. PMID:25408687

  15. Dynamics of Drosophila embryonic patterning network perturbed in space and time using microfluidics

    PubMed Central

    Lucchetta, Elena M.; Lee, Ji Hwan; Fu, Lydia A.; Patel, Nipam H.; Ismagilov, Rustem F.

    2009-01-01

    Biochemical networks are perturbed both by fluctuations in environmental conditions and genetic variation. These perturbations must be compensated for, especially when they occur during embryonic pattern formation. Complex chemical reaction networks displaying spatiotemporal dynamics have been controlled and understood by perturbing their environment in space and time1–3. Here, we apply this approach using microfluidics to investigate the robust network in Drosophila melanogaster that compensates for variation in the Bicoid morphogen gradient. We show that the compensation system can counteract the effects of extremely unnatural environmental conditions—a temperature step—in which the anterior and posterior halves of the embryo are developing at different temperatures and thus at different rates. Embryonic patterning was normal under this condition, suggesting that a simple reciprocal gradient system is not the mechanism of compensation. Time-specific reversals of the temperature step narrowed down the critical period for compensation to between 65 and 100 min after onset of embryonic development. The microfluidic technology used here may prove useful to future studies, as it allows spatial and temporal regulation of embryonic development. PMID:15858575

  16. Asparagus cochinchinensis Extract Alleviates Metal Ion-Induced Gut Injury in Drosophila: An In Silico Analysis of Potential Active Constituents

    PubMed Central

    Zhang, Weiyu; Jin, Li Hua

    2016-01-01

    Metal ions and sulfate are components of atmospheric pollutants that have diverse ways of entering the human body. We used Drosophila as a model to investigate the effect of Asparagus cochinchinensis (A. cochinchinensis) extracts on the gut and characterized gut homeostasis following the ingestion of metal ions (copper, zinc, and aluminum). In this study, we found that the aqueous A. cochinchinensis extract increased the survival rate, decreased epithelial cell death, and attenuated metal ion-induced gut morphological changes in flies following chronic exposure to metal ions. In addition, we screened out, by network pharmacology, six natural products (NPs) that could serve as putative active components of A. cochinchinensis that prevented gut injury. Altogether, the results of our study provide evidence that A. cochinchinensis might be an effective phytomedicine for the treatment of metal ion-induced gut injury. PMID:27123034

  17. Asparagus cochinchinensis Extract Alleviates Metal Ion-Induced Gut Injury in Drosophila: An In Silico Analysis of Potential Active Constituents.

    PubMed

    Zhang, Weiyu; Jin, Li Hua

    2016-01-01

    Metal ions and sulfate are components of atmospheric pollutants that have diverse ways of entering the human body. We used Drosophila as a model to investigate the effect of Asparagus cochinchinensis (A. cochinchinensis) extracts on the gut and characterized gut homeostasis following the ingestion of metal ions (copper, zinc, and aluminum). In this study, we found that the aqueous A. cochinchinensis extract increased the survival rate, decreased epithelial cell death, and attenuated metal ion-induced gut morphological changes in flies following chronic exposure to metal ions. In addition, we screened out, by network pharmacology, six natural products (NPs) that could serve as putative active components of A. cochinchinensis that prevented gut injury. Altogether, the results of our study provide evidence that A. cochinchinensis might be an effective phytomedicine for the treatment of metal ion-induced gut injury. PMID:27123034

  18. Discovery of progenitor cell signatures by time-series synexpression analysis during Drosophila embryonic cell immortalization

    PubMed Central

    Dequéant, Mary-Lee; Fagegaltier, Delphine; Hu, Yanhui; Spirohn, Kerstin; Simcox, Amanda; Hannon, Gregory J.; Perrimon, Norbert

    2015-01-01

    The use of time series profiling to identify groups of functionally related genes (synexpression groups) is a powerful approach for the discovery of gene function. Here we apply this strategy during RasV12 immortalization of Drosophila embryonic cells, a phenomenon not well characterized. Using high-resolution transcriptional time-series datasets, we generated a gene network based on temporal expression profile similarities. This analysis revealed that common immortalized cells are related to adult muscle precursors (AMPs), a stem cell-like population contributing to adult muscles and sharing properties with vertebrate satellite cells. Remarkably, the immortalized cells retained the capacity for myogenic differentiation when treated with the steroid hormone ecdysone. Further, we validated in vivo the transcription factor CG9650, the ortholog of mammalian Bcl11a/b, as a regulator of AMP proliferation predicted by our analysis. Our study demonstrates the power of time series synexpression analysis to characterize Drosophila embryonic progenitor lines and identify stem/progenitor cell regulators. PMID:26438832

  19. Embryonic development of the Drosophila brain: formation of commissural and descending pathways.

    PubMed

    Therianos, S; Leuzinger, S; Hirth, F; Goodman, C S; Reichert, H

    1995-11-01

    The establishment of initial axonal pathways in the embryonic brain of Drosophila melanogaster was investigated at the cellular and molecular level using antibody probes, enhancer detector strains and axonal pathfinding mutants. During embryogenesis, two bilaterally symmetrical cephalic neurogenic regions form, which are initially separated from each other and from the ventral nerve cord. The brain commissure that interconnects the two brain hemispheres is pioneered by axons that project towards the midline in close association with an interhemispheric cellular bridge. The descending longitudinal pathways that interconnect the brain to the ventral nerve cord are prefigured by a chain of longitudinal glial cells and a cellular bridge between brain and subesophageal ganglion; pioneering descending and ascending neurons grow in close association with these structures. The formation of the embryonic commissural and longitudinal pathways is dependent on cells of the CNS midline. Mutations in the commissureless gene, which affects growth cone guidance towards the midline, result in a marked reduction of the brain commissure. Mutations in the single-minded gene and in other spitz group genes, which affect the differentiation of CNS midline cells, result in the absence or aberrant projection of longitudinal pathways. The analysis of axon pathway formation presented here reveals remarkable similarities as well as distinct differences in the embryonic development of the brain and the segmental ganglia, and forms the basis for a comprehensive genetic and molecular genetic dissection of axonal pathfinding processes in the developing brain. PMID:8582294

  20. JNK activity in somatic stem cells causes loss of tissue homeostasis in the aging Drosophila gut

    PubMed Central

    Biteau, Benoît; Hochmuth, Christine E.; Jasper, Heinrich

    2011-01-01

    Metazoans employ cytoprotective and regenerative strategies to maintain tissue homeostasis. Understanding the coordination of these strategies is critical to develop accurate models for aging and associated diseases. Here we show that cytoprotective Jun-N-terminal Kinase (JNK) signaling influences regeneration in the Drosophila gut by directing proliferation of intestinal stem cells (ISCs). Interestingly, this function of JNK contributes to the loss of tissue homeostasis in old and stressed intestines by promoting the accumulation of mis-differentiated ISC daughter cells. Ectopic Delta/Notch signaling in these cells causes their abnormal differentiation, but also limits JNK-induced proliferation. Protective JNK signaling, and control of cell proliferation and differentiation by Delta/Notch signaling thus have to be carefully balanced to ensure tissue homeostasis. Our findings suggest that this balance is lost in old animals, increasing the potential for neoplastic transformation. PMID:18940735

  1. The role of the microbial environment in Drosophila post-embryonic development.

    PubMed

    Strigini, Maura; Leulier, François

    2016-11-01

    Development, growth and maturation of animals are under genetic and environmental control. Multicellular organisms interact throughout their lives with a variety of environment- and body-associated microorganisms. It has now been appreciated that the very conspicuous and varied microbial population associated with the food and the gastro-intestinal tract is a critical factor that can influence growth. Beyond the phenomenology, the mechanisms underlying the beneficial effects of microbes on development are being revealed from studies in Drosophila melanogaster, a particularly well suited system for a mechanistic understanding of host/microbiota interactions. Association of otherwise germ-free eggs with specific bacterial strains isolated from Drosophila gut samples can accelerate growth in larvae raised on restrictive diets. We review advances made possible by the exploitation of such simplified gnotobiotic systems in the search for the genes, molecules and physiological adaptations responsible for this effect in both host and microbes. Transposon mutagenesis and gene-trait match studies in bacteria can identify the key microbial genes and metabolites required for the beneficial effect, acetic acid being one of them. In the fly, functional genomic analysis, transcriptomics and metabolomics point to the modulation of systemic insulin and steroid hormone signalling as well as the regulation of intestinal physiology, including the enhancement of intestinal protease activity, as crucial mediators of the host's response. PMID:26827889

  2. A Cell Marker System and Mosaic Patterns during Early Embryonic Development in Drosophila melanogaster

    PubMed Central

    Zusman, Susan B.; Wieschaus, Eric

    1987-01-01

    An embryonic cell marker system has been developed in Drosophila melanogaster that has enabled us to identify the genotype of cells as early as the cellular blastoderm stage of development. This system allows unambiguous detection of embryos homozygous for most X-linked lethal mutations at stages prior to when their first defects become obvious. By examining gynandromorphs at this stage, we have observed that the number of nuclei per unit area in male regions is about half that in female regions. An examination of early cleavage stage embryos whose DNA has been stained with Hoechst 33258 and whose actin has been stained with phalloidin suggests that this difference is due to a cell cycle delay in cells losing the ring-X. These experiments also demonstrate the existence of a mechanism which controls the timing of nuclear divisions in cycle 10–14 embryos. PMID:3108074

  3. Requirement for highly efficient pre-mRNA splicing during Drosophila early embryonic development

    PubMed Central

    Guilgur, Leonardo Gastón; Prudêncio, Pedro; Sobral, Daniel; Liszekova, Denisa; Rosa, André; Martinho, Rui Gonçalo

    2014-01-01

    Drosophila syncytial nuclear divisions limit transcription unit size of early zygotic genes. As mitosis inhibits not only transcription, but also pre-mRNA splicing, we reasoned that constraints on splicing were likely to exist in the early embryo, being splicing avoidance a possible explanation why most early zygotic genes are intronless. We isolated two mutant alleles for a subunit of the NTC/Prp19 complexes, which specifically impaired pre-mRNA splicing of early zygotic but not maternally encoded transcripts. We hypothesized that the requirements for pre-mRNA splicing efficiency were likely to vary during development. Ectopic maternal expression of an early zygotic pre-mRNA was sufficient to suppress its splicing defects in the mutant background. Furthermore, a small early zygotic transcript with multiple introns was poorly spliced in wild-type embryos. Our findings demonstrate for the first time the existence of a developmental pre-requisite for highly efficient splicing during Drosophila early embryonic development and suggest in highly proliferative tissues a need for coordination between cell cycle and gene architecture to ensure correct gene expression and avoid abnormally processed transcripts. DOI: http://dx.doi.org/10.7554/eLife.02181.001 PMID:24755291

  4. An embryonic myosin isoform enables stretch activation and cyclical power in Drosophila jump muscle.

    PubMed

    Zhao, Cuiping; Swank, Douglas M

    2013-06-18

    The mechanism behind stretch activation (SA), a mechanical property that increases muscle force and oscillatory power generation, is not known. We used Drosophila transgenic techniques and our new muscle preparation, the jump muscle, to determine if myosin heavy chain isoforms influence the magnitude and rate of SA force generation. We found that Drosophila jump muscles show very low SA force and cannot produce positive power under oscillatory conditions at pCa 5.0. However, we transformed the jump muscle to be moderately stretch-activatable by replacing its myosin isoform with an embryonic isoform (EMB). Expressing EMB, jump muscle SA force increased by 163% and it generated net positive power. The rate of SA force development decreased by 58% with EMB expression. Power generation is Pi dependent as >4 mM Pi was required for positive power from EMB. Pi increased EMB SA force, but not wild-type SA force. Our data suggest that when muscle expressing EMB is stretched, EMB is more easily driven backward to a weakly bound state than wild-type jump muscle. This increases the number of myosin heads available to rapidly bind to actin and contribute to SA force generation. We conclude that myosin heavy chain isoforms influence both SA kinetics and SA force, which can determine if a muscle is capable of generating oscillatory power at a fixed calcium concentration. PMID:23790374

  5. The role of Dichaete in transcriptional regulation during Drosophila embryonic development

    PubMed Central

    2013-01-01

    Background Group B Sox domain transcription factors play conserved roles in the specification and development of the nervous system in higher metazoans. However, we know comparatively little about how these transcription factors regulate gene expression, and the analysis of Sox gene function in vertebrates is confounded by functional compensation between three closely related family members. In Drosophila, only two group B Sox genes, Dichaete and SoxN, have been shown to function during embryonic CNS development, providing a simpler system for understanding the functions of this important class of regulators. Results Using a combination of transcriptional profiling and genome-wide binding analysis we conservatively identify over 1000 high confidence direct Dichaete target genes in the Drosophila genome. We show that Dichaete plays key roles in CNS development, regulating aspects of the temporal transcription factor sequence that confer neuroblast identity. Dichaete also shows a complex interaction with Prospero in the pathway controlling the switch from stem cell self-renewal to neural differentiation. Dichaete potentially regulates many more genes in the Drosophila genome and was found to be associated with over 2000 mapped regulatory elements. Conclusions Our analysis suggests that Dichaete acts as a transcriptional hub, controlling multiple regulatory pathways during CNS development. These include a set of core CNS expressed genes that are also bound by the related Sox2 gene during mammalian CNS development. Furthermore, we identify Dichaete as one of the transcription factors involved in the neural stem cell transcriptional network, with evidence supporting the view that Dichaete is involved in controlling the temporal series of divisions regulating neuroblast identity. PMID:24314314

  6. An embryonic myosin converter domain influences Drosophila indirect flight muscle stretch activation, power generation and flight

    PubMed Central

    Wang, Qian; Newhard, Christopher S.; Ramanath, Seemanti; Sheppard, Debra; Swank, Douglas M.

    2014-01-01

    Stretch activation (SA) is critical to the flight ability of insects powered by asynchronous, indirect flight muscles (IFMs). An essential muscle protein component for SA and power generation is myosin. Which structural domains of myosin are significant for setting SA properties and power generation levels is poorly understood. We made use of the transgenic techniques and unique single muscle myosin heavy chain gene of Drosophila to test the influence of the myosin converter domain on IFM SA and power generation. Replacing the endogenous converter with an embryonic version decreased SA tension and the rate of SA tension generation. The alterations in SA properties and myosin kinetics from the converter exchange caused power generation to drop to 10% of control fiber power when the optimal conditions for control fibers – 1% muscle length (ML) amplitude and 150 Hz oscillation frequency – were applied to fibers expressing the embryonic converter (IFI-EC). Optimizing conditions for IFI-EC fiber power production, by doubling ML amplitude and decreasing oscillation frequency by 60%, improved power output to 60% of optimized control fiber power. IFI-EC flies altered their aerodynamic flight characteristics to better match optimal fiber power generation conditions as wing beat frequency decreased and wing stroke amplitude increased. This enabled flight in spite of the drastic changes to fiber mechanical performance. PMID:24115062

  7. vasa is expressed in somatic cells of the embryonic gonad in a sex-specific manner in Drosophila melanogaster

    PubMed Central

    Renault, Andrew D.

    2012-01-01

    Summary Vasa is a DEAD box helicase expressed in the Drosophila germline at all stages of development. vasa homologs are found widely in animals and vasa has become the gene of choice in identifying germ cells. I now show that Drosophila vasa expression is not restricted to the germline but is also expressed in a somatic lineage, the embryonic somatic gonadal precursor cells. This expression is sexually dimorphic, being maintained specifically in males, and is regulated post-transcriptionally. Although somatic Vasa expression is not required for gonad coalescence, these data support the notion that Vasa is not solely a germline factor. PMID:23213382

  8. Drosophila melanogaster - an embryonic model for studying behavioral and biochemical effects of manganese exposure.

    PubMed

    Ternes, Ana Paula Lausmann; Zemolin, Ana Paula; da Cruz, Litiele Cezar; da Silva, Gustavo Felipe; Saidelles, Ana Paula Fleig; de Paula, Mariane Trindade; Wagner, Caroline; Golombieski, Ronaldo Medeiros; Flores, Érico Marlon de Moraes; Picoloto, Rochele Sogari; Pereira, Antônio Batista; Franco, Jeferson Luis; Posser, Thaís

    2014-01-01

    Embryonic animals are especially susceptible to metal exposure. Manganese (Mn) is an essential element, but in excess it can induce toxicity. In this study we used Drosophila melanogaster as an embryonic model to investigate biochemical and behavioral alterations due to Mn exposure. Flies were treated with standard medium supplemented with MnCl2 at 0.1 mM, 0.5 mM or 1 mM from the egg to the adult stage. At 0.5 mM and 1 mM Mn, newly ecloded flies showed significantly enhanced locomotor activity when assessed by negative geotaxis behavior. In addition, a significant increase in Mn levels (p < 0.0001) was observed, while Ca, Fe, Cu, Zn and S levels were significantly decreased. A significant drop in cell viability occurred in flies exposed to 1 mM Mn. There was also an induction of reactive oxygen species at 0.5 mM and 1 mM Mn (p < 0.05). At 1 mM, Mn increased Catalase (p < 0.005), Superoxide Dismutase (p < 0.005) and Hsp83 (p < 0.0001) mRNA expression, without altering Catalase or Superoxide Dismutase activity; the activity of Thioredoxin reductase and Glutatione-S-transferase enzymes was increased. Mn treatment did not alter ERK or JNK1/2 phosphorylation, but at 1 mM caused an inhibition of p38(MAPK) phosphorylation. Together these data suggest mechanisms of adaptation in the fly response to Mn exposure in embryonic life. PMID:26417337

  9. Drosophila melanogaster - an embryonic model for studying behavioral and biochemical effects of manganese exposure

    PubMed Central

    Ternes, Ana Paula Lausmann; Zemolin, Ana Paula; da Cruz, Litiele Cezar; da Silva, Gustavo Felipe; Saidelles, Ana Paula Fleig; de Paula, Mariane Trindade; Wagner, Caroline; Golombieski, Ronaldo Medeiros; Flores, Érico Marlon de Moraes; Picoloto, Rochele Sogari; Pereira, Antônio Batista; Franco, Jeferson Luis; Posser, Thaís

    2014-01-01

    Embryonic animals are especially susceptible to metal exposure. Manganese (Mn) is an essential element, but in excess it can induce toxicity. In this study we used Drosophila melanogaster as an embryonic model to investigate biochemical and behavioral alterations due to Mn exposure. Flies were treated with standard medium supplemented with MnCl2 at 0.1 mM, 0.5 mM or 1 mM from the egg to the adult stage. At 0.5 mM and 1 mM Mn, newly ecloded flies showed significantly enhanced locomotor activity when assessed by negative geotaxis behavior. In addition, a significant increase in Mn levels (p < 0.0001) was observed, while Ca, Fe, Cu, Zn and S levels were significantly decreased. A significant drop in cell viability occurred in flies exposed to 1 mM Mn. There was also an induction of reactive oxygen species at 0.5 mM and 1 mM Mn (p < 0.05). At 1 mM, Mn increased Catalase (p < 0.005), Superoxide Dismutase (p < 0.005) and Hsp83 (p < 0.0001) mRNA expression, without altering Catalase or Superoxide Dismutase activity; the activity of Thioredoxin reductase and Glutatione-S-transferase enzymes was increased. Mn treatment did not alter ERK or JNK1/2 phosphorylation, but at 1 mM caused an inhibition of p38MAPK phosphorylation. Together these data suggest mechanisms of adaptation in the fly response to Mn exposure in embryonic life. PMID:26417337

  10. Biphasic modulation of synaptic transmission by hypertonicity at the embryonic Drosophila neuromuscular junction

    PubMed Central

    Suzuki, Kazuhiro; Okamoto, Tomonori; Kidokoro, Yoshiaki

    2002-01-01

    Puff-application of hypertonic saline (sucrose added to external saline) causes a transient increase in the frequency of spontaneous miniature synaptic currents (mSCs) at the neuromuscular junctions of Drosophila embryos. The frequency gradually returns to pre-application levels. External Ca2+ is not needed for this response, but it may modify it. At 50 mm added sucrose, for example, enhanced spontaneous release was observed only in the presence of external Ca2+, suggesting that Ca2+ augments the response. In a high-K+ solution, in which the basal mSC frequency was elevated, higher sucrose concentrations produced an increase in mSC frequency that was followed (during and after the hypertonic exposure) by depression, with the magnitude of both effects increasing with hypertonicity between 100 and 500 mm. Evoked release by nerve stimulation showed only depression in response to hypertonicity. We do not believe that the depression of spontaneous or evoked release can be explained by the depletion of releasable quanta, however, since the frequency of quantal release did not reach levels compatible with this explanation and the enhancement and depression could be obtained independent of one another. In a mutant lacking neuronal synaptobrevin, only the depression of mSC frequency was induced by hypertonicity. Conversely, only the enhancing effect was observed in wild-type embryos when the mSC frequency was elevated with forskolin in Ca2+-free saline. In cultured embryonic Drosophila neurons, Ca2+ signals that were induced by high K+ and detected by Fura-2, were reduced by hypertonicity, suggesting that the depressing response is due to a direct effect of hypertonicity on Ca2+ influx. PMID:12433954

  11. Reduced Gut Acidity Induces an Obese-Like Phenotype in Drosophila melanogaster and in Mice

    PubMed Central

    Yen, Jui-Hung; Kuo, Ping-Chang; Yeh, Sheng-Rong; Lin, Hung-Yu; Fu, Tsai-Feng; Wu, Ming-Shiang; Wang, Horng-Dar; Wang, Pei-Yu

    2015-01-01

    In order to identify genes involved in stress and metabolic regulation, we carried out a Drosophila P-element-mediated mutagenesis screen for starvation resistance. We isolated a mutant, m2, that showed a 23% increase in survival time under starvation conditions. The P-element insertion was mapped to the region upstream of the vha16-1 gene, which encodes the c subunit of the vacuolar-type H+-ATPase. We found that vha16-1 is highly expressed in the fly midgut, and that m2 mutant flies are hypomorphic for vha16-1 and also exhibit reduced midgut acidity. This deficit is likely to induce altered metabolism and contribute to accelerated aging, since vha16-1 mutant flies are short-lived and display increases in body weight and lipid accumulation. Similar phenotypes were also induced by pharmacological treatment, through feeding normal flies and mice with a carbonic anhydrase inhibitor (acetazolamide) or proton pump inhibitor (PPI, lansoprazole) to suppress gut acid production. Our study may thus provide a useful model for investigating chronic acid suppression in patients. PMID:26436771

  12. Predetermined embryonic glial cells form the distinct glial sheaths of the Drosophila peripheral nervous system

    PubMed Central

    von Hilchen, Christian M.; Bustos, Álvaro E.; Giangrande, Angela; Technau, Gerhard M.; Altenhein, Benjamin

    2013-01-01

    One of the numerous functions of glial cells in Drosophila is the ensheathment of neurons to isolate them from the potassium-rich haemolymph, thereby establishing the blood-brain barrier. Peripheral nerves of flies are surrounded by three distinct glial cell types. Although all embryonic peripheral glia (ePG) have been identified on a single-cell level, their contribution to the three glial sheaths is not known. We used the Flybow system to label and identify each individual ePG in the living embryo and followed them into third instar larva. We demonstrate that all ePG persist until the end of larval development and some even to adulthood. We uncover the origin of all three glial sheaths and describe the larval differentiation of each peripheral glial cell in detail. Interestingly, just one ePG (ePG2) exhibits mitotic activity during larval stages, giving rise to up to 30 glial cells along a single peripheral nerve tract forming the outermost perineurial layer. The unique mitotic ability of ePG2 and the layer affiliation of additional cells were confirmed by in vivo ablation experiments and layer-specific block of cell cycle progression. The number of cells generated by this glial progenitor and hence the control of perineurial hyperplasia correlate with the length of the abdominal nerves. By contrast, the wrapping and subperineurial glia layers show enormous hypertrophy in response to larval growth. This characterisation of the embryonic origin and development of each glial sheath will facilitate functional studies, as they can now be addressed distinctively and genetically manipulated in the embryo. PMID:23903191

  13. Gene expression patterns in primary neuronal clusters of the Drosophila embryonic brain

    PubMed Central

    Sprecher, Simon G.; Reichert, Heinrich; Hartenstein, Volker

    2014-01-01

    The brain of Drosophila is formed by approximately 100 lineages, each lineage being derived from a stem cell-like neuroblast that segregates from the procephalic neurectoderm of the early embryo. A neuroblast map has been established in great detail for the early embryo, and a suite of molecular markers has been defined for all neuroblasts included in this map (Urbach and Technau, 2003a). However, the expression of these markers was not followed into later embryonic or larval stages, mainly due to the fact that anatomical landmarks to which expression patterns could be related had not been defined. Such markers, in the form of stereotyped clusters of neurons whose axons project along cohesive bundles (“primary axon bundles” or “PABs”) are now available (Younossi-Hartenstein et al., 2006). In the present study we have mapped the expression of molecular markers in relationship to primary neuronal clusters and their PABs. The markers we analyzed include many of the genes involved in patterning of the brain along the anteroposterior axis (cephalic gap genes, segment polarity genes) and dorso-ventral axis (columnar patterning genes), as well as genes expressed in the dorsal protocerebrum and visual system (early eye genes). Our analysis represents an important step along the way to identify neuronal lineages of the mature brain with genes expressed in the early embryo in discrete neuroblasts. Furthermore, the analysis helped us to reconstruct the morphogenetic movements that transform the two-dimensional neuroblast layer of the early embryo into the three-dimensional larval brain and provides the basis for deeper understanding of how the embryonic brain develops. PMID:17300994

  14. Septate Junction Proteins Play Essential Roles in Morphogenesis Throughout Embryonic Development in Drosophila

    PubMed Central

    Hall, Sonia; Ward, Robert E.

    2016-01-01

    The septate junction (SJ) is the occluding junction found in the ectodermal epithelia of invertebrate organisms, and is essential to maintain chemically distinct compartments in epithelial organs, to provide the blood–brain barrier in the nervous system, and to provide an important line of defense against invading pathogens. More than 20 genes have been identified to function in the establishment or maintenance of SJs in Drosophila melanogaster. Numerous studies have demonstrated the cell biological function of these proteins in establishing the occluding junction, whereas very few studies have examined further developmental roles for them. Here we examined embryos with mutations in nine different core SJ genes and found that all nine result in defects in embryonic development as early as germ band retraction, with the most penetrant defect observed in head involution. SJ genes are also required for cell shape changes and cell rearrangements that drive the elongation of the salivary gland during midembryogenesis. Interestingly, these developmental events occur at a time prior to the formation of the occluding junction, when SJ proteins localize along the lateral membrane and have not yet coalesced into the region of the SJ. Together, these observations reveal an underappreciated role for a large group of SJ genes in essential developmental events during embryogenesis, and suggest that the function of these proteins in facilitating cell shape changes and rearrangements is independent of their role in the occluding junction. PMID:27261004

  15. The role of Wg signaling in the patterning of embryonic leg primordium in Drosophila.

    PubMed

    Kubota, Kazumasa; Goto, Satoshi; Hayashi, Shigeo

    2003-05-01

    Cellular interaction between the proximal and distal domains of the limb plays key roles in proximal-distal patterning. In Drosophila, these domains are established in the embryonic leg imaginal disc as a proximal domain expressing escargot, surrounding the Distal-less expressing distal domain in a circular pattern. The leg imaginal disc is derived from the limb primordium that also gives rise to the wing imaginal disc. We describe here essential roles of Wingless in patterning the leg imaginal disc. Firstly, Wingless signaling is essential for the recruitment of dorsal-proximal, distal, and ventral-proximal leg cells. Wingless requirement in the proximal leg domain appears to be unique to the embryo, since it was previously shown that Wingless signal transduction is not active in the proximal leg domain in larvae. Secondly, downregulation of Wingless signaling in wing disc is essential for its development, suggesting that Wg activity must be downregulated to separate wing and leg discs. In addition, we provide evidence that Dll restricts expression of a proximal leg-specific gene expression. We propose that those embryo-specific functions of Wingless signaling reflect its multiple roles in restricting competence of ectodermal cells to adopt the fate of thoracic appendages. PMID:12710961

  16. The Cre-Binding Protein Dcreb-a Is Required for Drosophila Embryonic Development

    PubMed Central

    Rose, R. E.; Gallaher, N. M.; Andrew, D. J.; Goodman, R. H.; Smolik, S. M.

    1997-01-01

    We have previously described the cloning of a cyclic AMP response-element (CRE)-binding protein, dCREB-A, in Drosophila melanogaster that is similar to the mammalian CRE-binding protein CREB. dCREB-A is a member of the bZIP family of transcription factors, shows specific binding to the (CRE), and can activate transcription in cell culture. In this report, we describe the gene structure for dCREB-A, protein expression patterns throughout development and the necessary role for this gene in embryogenesis. The 4.5-kb transcript is encoded in six exons that are distributed over 21 kb of DNA. There are seven start sites and no TATA consensus sequences upstream. The dCREB-A protein is expressed in the nuclei of the embryonic salivary gland, proventriculus and stomadeum. Late in embryogenesis, tracheal cell nuclei and specific nuclei within the segments show staining with anti-dCREB-A antibodies. In adult female ovaries, dCREB-A is expressed in the stage 9 through stage 11 follicle cell nuclei. Null mutations of the dCREB-A gene give rise to animals that no longer express dCREB-A protein and die late in embryogenesis before or at hatching. The absolute requirement of dCREB-A for embryogenesis demonstrates a nonredundant function for a CRE-binding protein that will be useful in studying the role of specific signal transduction cascades in development. PMID:9178009

  17. Septate Junction Proteins Play Essential Roles in Morphogenesis Throughout Embryonic Development in Drosophila.

    PubMed

    Hall, Sonia; Ward, Robert E

    2016-01-01

    The septate junction (SJ) is the occluding junction found in the ectodermal epithelia of invertebrate organisms, and is essential to maintain chemically distinct compartments in epithelial organs, to provide the blood-brain barrier in the nervous system, and to provide an important line of defense against invading pathogens. More than 20 genes have been identified to function in the establishment or maintenance of SJs in Drosophila melanogaster Numerous studies have demonstrated the cell biological function of these proteins in establishing the occluding junction, whereas very few studies have examined further developmental roles for them. Here we examined embryos with mutations in nine different core SJ genes and found that all nine result in defects in embryonic development as early as germ band retraction, with the most penetrant defect observed in head involution. SJ genes are also required for cell shape changes and cell rearrangements that drive the elongation of the salivary gland during midembryogenesis. Interestingly, these developmental events occur at a time prior to the formation of the occluding junction, when SJ proteins localize along the lateral membrane and have not yet coalesced into the region of the SJ. Together, these observations reveal an underappreciated role for a large group of SJ genes in essential developmental events during embryogenesis, and suggest that the function of these proteins in facilitating cell shape changes and rearrangements is independent of their role in the occluding junction. PMID:27261004

  18. Homeostatic epithelial renewal in the gut is required for dampening a fatal systemic wound response in Drosophila.

    PubMed

    Takeishi, Asuka; Kuranaga, Erina; Tonoki, Ayako; Misaki, Kazuyo; Yonemura, Shigenobu; Kanuka, Hirotaka; Miura, Masayuki

    2013-03-28

    Effective defense responses involve the entire organism. To maintain body homeostasis after tissue damage, a systemic wound response is induced in which the response of each tissue is tightly orchestrated to avoid incomplete recovery or an excessive, damaging response. Here, we provide evidence that in the systemic response to wounding, an apoptotic caspase pathway is activated downstream of reactive oxygen species in the midgut enterocytes (ECs), cells distant from the wound site, in Drosophila. We show that a caspase-pathway mutant has defects in homeostatic gut cell renewal and that inhibiting caspase activity in fly ECs results in the production of systemic lethal factors after wounding. Our results indicate that wounding remotely controls caspase activity in ECs, which activates the tissue stem cell regeneration pathway in the gut to dampen the dangerous systemic wound reaction. PMID:23523355

  19. Embryonic development of the Drosophila brain. II. Pattern of glial cells.

    PubMed

    Hartenstein, V; Nassif, C; Lekven, A

    1998-12-01

    Glial cells in Drosophila and other insects are organized in an outer layer that envelops the surface of the central and peripheral nervous system (subperineurial glia, peripheral glia), a middle layer associated with neuronal somata in the cortex (cell body glia), and an inner layer surrounding the neuropile (longitudinal glia, midline glia, nerve root glia). In the ventral nerve cord, most glial cells are formed by a relatively small number of neuro-glioblasts; subsequently, glial cell precursors migrate and spread out widely to reach their final destination. By using a glia-specific marker (antibody against the Repo protein) we have reconstructed the pattern of glial cell precursors at successive developmental stages, focusing on the glia of the supraesophageal ganglion and subesophageal ganglion which are not described in previous studies. Digitized images of consecutive optical sections were used to generate 3-D models that show the spatial pattern of glial cell precursors in relationship to the neuropile, brain surface, and peripheral nerves. Similar to their spatial organization in the ventral nerve cord, glial cells of the brain populate the brain nerves and outer surface, cortical cell body layer, and cortex-neuropile interface. Neuropile-associated glial cells arise from a cluster located at the base of the supraesophageal ganglion; from this position, they migrate dorsally along the developing axon tracts and by late embryonic stages form a sheath around all neuropile compartments, including the supraesophageal commissure. Surface and cell body glial cells derive from several discrete foci, notably two large clusters at the deuterocerebrum/protocerebrum boundary and the posterior protocerebrum. From these foci, glial cells then fan out to envelop the surface of the supraesophageal ganglion. PMID:9831044

  20. Functional equivalence of Hox gene products in the specification of the tritocerebrum during embryonic brain development of Drosophila.

    PubMed

    Hirth, F; Loop, T; Egger, B; Miller, D F; Kaufman, T C; Reichert, H

    2001-12-01

    Hox genes encode evolutionarily conserved transcription factors involved in the specification of segmental identity during embryonic development. This specification of identity is thought to be directed by differential Hox gene action, based on differential spatiotemporal expression patterns, protein sequence differences, interactions with co-factors and regulation of specific downstream genes. During embryonic development of the Drosophila brain, the Hox gene labial is required for the regionalized specification of the tritocerebral neuromere; in the absence of labial, the cells in this brain region do not acquire a neuronal identity and major axonal pathfinding deficits result. We have used genetic rescue experiments to investigate the functional equivalence of the Drosophila Hox gene products in the specification of the tritocerebral neuromere. Using the Gal4-UAS system, we first demonstrate that the labial mutant brain phenotype can be rescued by targeted expression of the Labial protein under the control of CNS-specific labial regulatory elements. We then show that under the control of these CNS-specific regulatory elements, all other Drosophila Hox gene products, except Abdominal-B, are able to efficiently replace Labial in the specification of the tritocerebral neuromere. We also observe a correlation between the rescue efficiency of the Hox proteins and the chromosomal arrangement of their encoding loci. Our results indicate that, despite considerably diverged sequences, most Hox proteins are functionally equivalent in their ability to replace Labial in the specification of neuronal identity. This suggests that in embryonic brain development, differences in Hox gene action rely mainly on cis-acting regulatory elements and not on Hox protein specificity. PMID:11731458

  1. Analysis of Drosophila melanogaster proteome dynamics during embryonic development by a combination of label-free proteomics approaches.

    PubMed

    Fabre, Bertrand; Korona, Dagmara; Groen, Arnoud; Vowinckel, Jakob; Gatto, Laurent; Deery, Michael J; Ralser, Markus; Russell, Steven; Lilley, Kathryn S

    2016-08-01

    During embryogenesis, organisms undergo considerable cellular remodelling requiring the combined action of thousands of proteins. In case of the well-studied model Drosophila melanogaster, transcriptomic studies, most notably from the modENCODE project, have described in detail changes in gene expression at the mRNA level across development. Although such data are clearly very useful to understand how the genome is regulated during embryogenesis, it is important to understand how changes in gene expression are reflected at the level of the proteome. In this study, we describe a combination of two quantitative label-free approaches, SWATH and data-dependent acquisition, to monitor changes in protein expression across a timecourse of D. melanogaster embryonic development. We demonstrate that both approaches provide robust and reproducible methods for the analysis of proteome changes. In a preliminary analysis of Drosophila embryogenesis, we identified several pathways, including the heat-shock response, nuclear protein import and energy production that are regulated during embryo development. In some cases changes in protein expression mirrored transcript levels across development, whereas other proteins showed signatures of post-transcriptional regulation. Taken together, our pilot study provides a solid platform for a more detailed exploration of the embryonic proteome. PMID:27029218

  2. A novel sulfonylurea receptor family member expressed in the embryonic Drosophila dorsal vessel and tracheal system.

    PubMed

    Nasonkin, I; Alikasifoglu, A; Ambrose, C; Cahill, P; Cheng, M; Sarniak, A; Egan, M; Thomas, P M

    1999-10-01

    Sulfonylurea receptors (SURx) are required subunits of the ATP-sensitive potassium channel. SURx alone is electrophysiologically inert. However, when SURx is combined with an inward rectifier Kir6.2 subunit, ATP-sensitive potassium channel activity is generated. We report the identification, characterization, and localization of Dsur, a novel Drosophila gene that is highly related to the vertebrate SUR family. The Dsur coding sequence contains structural features characteristic of the ABC transporter family and, in addition, harbors 1.7 kilobases of a distinctive sequence that does not share homology with any known gene. When Dsur alone is expressed in Xenopus oocytes glibenclamide-sensitive potassium channel activity occurs. During Drosophila embryogenesis, the Dsur gene is specifically expressed in the developing tracheal system and dorsal vessel. Studies of the Drosophila genome support that only a single Dsur gene is present. Our data reveal conservation of glibenclamide-sensitive potassium channels in Drosophila and suggest that Dsur may play an important role during Drosophila embryogenesis. The lack of gene duplication in the Drosophila system provides a unique opportunity for functional studies of SUR using a genetic approach. PMID:10506204

  3. Two Enhancers Control Transcription of Drosophila muscleblind in the Embryonic Somatic Musculature and in the Central Nervous System

    PubMed Central

    Cerro-Herreros, Estefanía; Artero, Ruben

    2014-01-01

    The phylogenetically conserved family of Muscleblind proteins are RNA-binding factors involved in a variety of gene expression processes including alternative splicing regulation, RNA stability and subcellular localization, and miRNA biogenesis, which typically contribute to cell-type specific differentiation. In humans, sequestration of Muscleblind-like proteins MBNL1 and MBNL2 has been implicated in degenerative disorders, particularly expansion diseases such as myotonic dystrophy type 1 and 2. Drosophila muscleblind was previously shown to be expressed in embryonic somatic and visceral muscle subtypes, and in the central nervous system, and to depend on Mef2 for transcriptional activation. Genomic approaches have pointed out candidate gene promoters and tissue-specific enhancers, but experimental confirmation of their regulatory roles was lacking. In our study, luciferase reporter assays in S2 cells confirmed that regions P1 (515 bp) and P2 (573 bp), involving the beginning of exon 1 and exon 2, respectively, were able to initiate RNA transcription. Similarly, transgenic Drosophila embryos carrying enhancer reporter constructs supported the existence of two regulatory regions which control embryonic expression of muscleblind in the central nerve cord (NE, neural enhancer; 830 bp) and somatic (skeletal) musculature (ME, muscle enhancer; 3.3 kb). Both NE and ME were able to boost expression from the Hsp70 heterologous promoter. In S2 cell assays most of the ME enhancer activation could be further narrowed down to a 1200 bp subregion (ME.3), which contains predicted binding sites for the Mef2 transcription factor. The present study constitutes the first characterization of muscleblind enhancers and will contribute to a deeper understanding of the transcriptional regulation of the gene. PMID:24667536

  4. Genomewide analysis of the Drosophila tetraspanins reveals a subset with similar function in the formation of the embryonic synapse

    PubMed Central

    Fradkin, Lee G.; Kamphorst, Jessica T.; DiAntonio, Aaron; Goodman, Corey S.; Noordermeer, Jasprina N.

    2002-01-01

    Tetraspanins encode a large conserved family of proteins that span the membrane four times and are expressed in a variety of eukaryotic tissues. They are part of membrane complexes that are involved in such diverse processes as intracellular signaling, cellular motility, metastasis, and tumor suppression. The single fly tetraspanin characterized to date, late bloomer (lbm), is expressed on the axons, terminal arbors, and growth cones of motoneurons. In embryos lacking Lbm protein, motoneurons reach their muscle targets, but initially fail to form synaptic terminals. During larval stages, however, functional contacts are formed. The newly available genomic sequence of Drosophila melanogaster indicates the existence of 34 additional members of the tetraspanin family in the fly. To address the possibility that other tetraspanins with functions that might compensate for a lack of lbm exist, we determined the expression domains of the Drosophila tetraspanin gene family members by RNA in situ analysis. We found two other tetraspanins also expressed in motoneurons and subsequently generated a small chromosomal deletion that removes all three motoneuron-specific tetraspanins. The deletion results in a significant enhancement in the lbm phenotype, indicating that the two additional motoneuron-expressed tetraspanins can, at least in part, compensate for the absence of lbm during the formation of the embryonic synapse. PMID:12370414

  5. The Drosophila F-box protein Archipelago controls levels of the Trachealess transcription factor in the embryonic tracheal system

    PubMed Central

    Mortimer, Nathan T.; Moberg, Kenneth H.

    2007-01-01

    The archipelago gene (ago) encodes the F-box specificity subunit of an SCF(skp-cullin-f box) ubiquitin ligase that inhibits cell proliferation in Drosophila melanogaster and suppresses tumorigenesis in mammals. ago limits mitotic activity by targeting cell cycle and cell growth proteins for ubiquitin-dependent degradation, but the diverse developmental roles of other F-box proteins suggests that it is likely to have additional protein targets. Here we show that ago is required for the post-mitotic shaping of the Drosophila embryonic tracheal system, and that it acts in this tissue by targeting the Trachealess (Trh) protein, a conserved bHLH-PAS transcription factor. ago restricts Trh levels in vivo and antagonizes transcription of the breathless FGF receptor, a known target of Trh in the tracheal system. At a molecular level, the Ago protein binds Trh and is required for proteasome-dependent elimination of Trh in response to expression of the Dysfusion protein. ago mutations that elevate Trh levels in vivo are defective in binding forms of Trh found in Dysfusion-positive cells. These data identify a novel function for the ago ubiquitin-ligase in tracheal morphogenesis via Trh and its target breathless, and suggest that ago has distinct functions in mitotic and post-mitotic cells that influence its role in development and disease. PMID:17976568

  6. The Drosophila Retinoblastoma Binding Protein 6 Family Member Has Two Isoforms and Is Potentially Involved in Embryonic Patterning

    PubMed Central

    Hull, Rodney; Oosthuysen, Brent; Cajee, Umar-Faruq; Mokgohloa, Lehlogonolo; Nweke, Ekene; Antunes, Ricardo Jorge; Coetzer, Theresa H. T.; Ntwasa, Monde

    2015-01-01

    The human retinoblastoma binding protein 6 (RBBP6) is implicated in esophageal, lung, hepatocellular and colon cancers. Furthermore, RBBP6 was identified as a strong marker for colon cancer prognosis and as a predisposing factor in familial myeloproliferative neoplasms. Functionally, the mammalian protein interacts with p53 and enhances the activity of Mdm2, the prototypical negative regulator of p53. However, since RBBP6 (known as PACT in mice) exists in multiple isoforms and pact−/− mice exhibit a more severe phenotype than mdm2−/− mutants, it must possess some Mdm2-independent functions. The function of the invertebrate homologue is poorly understood. This is complicated by the absence of the Mdm2 gene in both Drosophila and Caenorhabditis elegans. We have experimentally identified the promoter region of Snama, the Drosophila homologue, analyzed potential transcription factor binding sites and confirmed the existence of an additional isoform. Using band shift and co-immunoprecipitation assays combined with mass spectrometry, we found evidence that this gene may be regulated by, amongst others, DREF, which regulates hundreds of genes related to cell proliferation. The potential transcription factors for Snama fall into distinct functional groups, including anteroposterior embryonic patterning and nucleic acid metabolism. Significantly, previous work in mice shows that pact−/− induces an anteroposterior phenotype in embryos when rescued by simultaneous deletion of p53. Taken together, these observations indicate the significance of RBBP6 proteins in carcinogenesis and in developmental defects. PMID:25955646

  7. Laser ablation of Drosophila embryonic motoneurons causes ectopic innervation of target muscle fibers

    NASA Technical Reports Server (NTRS)

    Chang, T. N.; Keshishian, H.

    1996-01-01

    We have tested the effects of neuromuscular denervation in Drosophila by laser-ablating the RP motoneurons in intact embryos before synaptogenesis. We examined the consequences of this ablation on local synaptic connectivity in both 1st and 3rd instar larvae. We find that the partial or complete loss of native innervation correlates with the appearance of alternate inputs from neighboring motor endings and axons. These collateral inputs are found at ectopic sites on the denervated target muscle fibers. The foreign motor endings are electrophysiologically functional and are observed on the denervated muscle fibers by the 1st instar larval stage. Our data are consistent with the existence of a local signal from the target environment, which is regulated by innervation and influences synaptic connectivity. Our results show that, despite the stereotypy of Drosophila neuromuscular connections, denervation can induce local changes in connectivity in wild-type Drosophila, suggesting that mechanisms of synaptic plasticity may also be involved in normal Drosophila neuromuscular development.

  8. The fruitless gene is required for the proper formation of axonal tracts in the embryonic central nervous system of Drosophila.

    PubMed Central

    Song, Ho-Juhn; Billeter, Jean-Christophe; Reynaud, Enrique; Carlo, Troy; Spana, Eric P; Perrimon, Norbert; Goodwin, Stephen F; Baker, Bruce S; Taylor, Barbara J

    2002-01-01

    The fruitless (fru) gene in Drosophila melanogaster is a multifunctional gene that has sex-specific functions in the regulation of male sexual behavior and sex-nonspecific functions affecting adult viability and external morphology. While much attention has focused on fru's sex-specific roles, less is known about its sex-nonspecific functions. We have examined fru's sex-nonspecific role in embryonic neural development. fru transcripts from sex-nonspecific promoters are expressed beginning at the earliest stages of neurogenesis, and Fru proteins are present in both neurons and glia. In embryos that lack most or all fru function, FasII- and BP102-positive axons have defasciculation defects and grow along abnormal pathways in the CNS. These defects in axonal projections in fru mutants were rescued by the expression of specific UAS-fru transgenes under the control of a pan-neuronal scabrous-GAL4 driver. Our results suggest that one of fru's sex-nonspecific roles is to regulate the pathfinding ability of axons in the embryonic CNS. PMID:12524343

  9. An F1 genetic screen for maternal-effect mutations affecting embryonic pattern formation in Drosophila melanogaster.

    PubMed Central

    Luschnig, Stefan; Moussian, Bernard; Krauss, Jana; Desjeux, Isabelle; Perkovic, Josip; Nüsslein-Volhard, Christiane

    2004-01-01

    Large-scale screens for female-sterile mutations have revealed genes required maternally for establishment of the body axes in the Drosophila embryo. Although it is likely that the majority of components involved in axis formation have been identified by this approach, certain genes have escaped detection. This may be due to (1) incomplete saturation of the screens for female-sterile mutations and (2) genes with essential functions in zygotic development that mutate to lethality, precluding their identification as female-sterile mutations. To overcome these limitations, we performed a genetic mosaic screen aimed at identifying new maternal genes required for early embryonic patterning, including zygotically required ones. Using the Flp-FRT technique and a visible germline clone marker, we developed a system that allows efficient screening for maternal-effect phenotypes after only one generation of breeding, rather than after the three generations required for classic female-sterile screens. We identified 232 mutants showing various defects in embryonic pattern or morphogenesis. The mutants were ordered into 10 different phenotypic classes. A total of 174 mutants were assigned to 86 complementation groups with two alleles on average. Mutations in 45 complementation groups represent most previously known maternal genes, while 41 complementation groups represent new loci, including several involved in dorsoventral, anterior-posterior, and terminal patterning. PMID:15166158

  10. Sonication-facilitated Immunofluorescence Staining of Late-stage Embryonic and Larval Drosophila Tissues In Situ

    PubMed Central

    Wawersik, Matthew

    2014-01-01

    Studies performed in Drosophila melanogaster embryos and larvae provide crucial insight into developmental processes such as cell fate specification and organogenesis. Immunostaining allows for the visualization of developing tissues and organs. However, a protective cuticle that forms at the end of embryogenesis prevents permeation of antibodies into late-stage embryos and larvae. While dissection prior to immunostaining is regularly used to analyze Drosophila larval tissues, it proves inefficient for some analyses because small tissues may be difficult to locate and isolate. Sonication provides an alternative to dissection in larval Drosophila immunostaining protocols. It allows for quick, simultaneous processing of large numbers of late-stage embryos and larvae and maintains in situ morphology. After fixation in formaldehyde, a sample is sonicated. Sample is then subjected to immunostaining with antigen-specific primary antibodies and fluorescently labeled secondary antibodies to visualize target cell types and specific proteins via fluorescence microscopy. During the process of sonication, proper placement of a sonicating probe above the sample, as well as the duration and intensity of sonication, is critical. Additonal minor modifications to standard immunostaining protocols may be required for high quality stains. For antibodies with low signal to noise ratio, longer incubation times are typically necessary. As a proof of concept for this sonication-facilitated protocol, we show immunostains of three tissue types (testes, ovaries, and neural tissues) at a range of developmental stages. PMID:25146311

  11. Regulation of the retinal determination gene dachshund in the embryonic head and developing eye of Drosophila

    PubMed Central

    Anderson, Jason; Salzer, Claire L.; Kumar, Justin P.

    2009-01-01

    The retinal determination gene dachshund is distantly related to the family of Ski/Sno proto-oncogenes and influences the development of a wide range of tissues including the embryonic head, optic lobes, brain, central nervous system as well as the post-embryonic leg, wing, genital and eye-antennal discs. We were interested in the regulatory mechanisms that control the dynamic expression pattern of dachshund and in this report we set out to ascertain how the transcription of dachshund is modulated in the embryonic head and developing eye-antennal imaginal disc. We demonstrate that the TGFβ signaling cascade, the transcription factor zerknullt and several other patterning genes prevent dachshund from being expressed inappropriately within the embryonic head. Additionally, we show that several members of the eye specification cascade influence the transcription of dachshund during normal and ectopic eye development. Our results suggest that dachshund is regulated by a complex combinatorial code of transcription factors and signaling pathways. Unraveling this code may lead to an understanding of how dachshund regulates the development of many diverse tissue types including the eye. PMID:16780828

  12. Friend, foe or food? Recognition and the role of antimicrobial peptides in gut immunity and Drosophila-microbe interactions.

    PubMed

    Broderick, Nichole A

    2016-05-26

    Drosophila melanogaster lives, breeds and feeds on fermenting fruit, an environment that supports a high density, and often a diversity, of microorganisms. This association with such dense microbe-rich environments has been proposed as a reason that D. melanogaster evolved a diverse and potent antimicrobial peptide (AMP) response to microorganisms, especially to combat potential pathogens that might occupy this niche. Yet, like most animals, D. melanogaster also lives in close association with the beneficial microbes that comprise its microbiota, or microbiome, and recent studies have shown that antimicrobial peptides (AMPs) of the epithelial immune response play an important role in dictating these interactions and controlling the host response to gut microbiota. Moreover, D. melanogaster also eats microbes for food, consuming fermentative microbes of decaying plant material and their by-products as both larvae and adults. The processes of nutrient acquisition and host defence are remarkably similar and use shared functions for microbe detection and response, an observation that has led to the proposal that the digestive and immune systems have a common evolutionary origin. In this manner, D. melanogaster provides a powerful model to understand how, and whether, hosts differentiate between the microbes they encounter across this spectrum of associations.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. PMID:27160597

  13. Proteomic Analysis of the Ubiquitin Landscape in the Drosophila Embryonic Nervous System and the Adult Photoreceptor Cells

    PubMed Central

    Ramirez, Juanma; Martinez, Aitor; Lectez, Benoit; Lee, So Young; Franco, Maribel; Barrio, Rosa; Dittmar, Gunnar; Mayor, Ugo

    2015-01-01

    Background Ubiquitination is known to regulate physiological neuronal functions as well as to be involved in a number of neuronal diseases. Several ubiquitin proteomic approaches have been developed during the last decade but, as they have been mostly applied to non-neuronal cell culture, very little is yet known about neuronal ubiquitination pathways in vivo. Methodology/Principal Findings Using an in vivo biotinylation strategy we have isolated and identified the ubiquitinated proteome in neurons both for the developing embryonic brain and for the adult eye of Drosophila melanogaster. Bioinformatic comparison of both datasets indicates a significant difference on the ubiquitin substrates, which logically correlates with the processes that are most active at each of the developmental stages. Detection within the isolated material of two ubiquitin E3 ligases, Parkin and Ube3a, indicates their ubiquitinating activity on the studied tissues. Further identification of the proteins that do accumulate upon interference with the proteasomal degradative pathway provides an indication of the proteins that are targeted for clearance in neurons. Last, we report the proof-of-principle validation of two lysine residues required for nSyb ubiquitination. Conclusions/Significance These data cast light on the differential and common ubiquitination pathways between the embryonic and adult neurons, and hence will contribute to the understanding of the mechanisms by which neuronal function is regulated. The in vivo biotinylation methodology described here complements other approaches for ubiquitome study and offers unique advantages, and is poised to provide further insight into disease mechanisms related to the ubiquitin proteasome system. PMID:26460970

  14. MUMMY, A UDP-N-ACETYLGLUCOSAMINE PYROPHOSPHORYLASE, MODULATES DPP SIGNALING IN THE EMBRYONIC EPIDERMIS OF DROSOPHILA

    PubMed Central

    HUMPHREYS, GREGORY B.; JUD, MOLLY C.; MONROE, KATHRYN M.; KIMBALL, SUZANNE S.; HIGLEY, MATTHEW; SHIPLEY, DANIELLE; VRABLIK, MARIE CLOUGHERTY; BATES, KATHERINE L.; LETSOU, ANTHEA

    2013-01-01

    The evolutionarily conserved JNK/AP-1 (Jun N-terminal kinase/activator protein 1) and BMP (Bone Morphogenetic Protein) signaling cascades are deployed hierarchically to regulate dorsal closure in the fruit fly Drosophila melanogaster. In this developmental context, the JNK/AP-1 signaling cascade transcriptionally activates BMP signaling in leading edge epidermal cells. Here we show that the mummy (mmy) gene product, which is required for dorsal closure, functions as a BMP signaling antagonist. Genetic and biochemical tests of Mmy’s role as a BMP-antagonist indicate that its function is independent of AP-1, the transcriptional trigger of BMP signal transduction in leading edge cells. pMAD (phosphorylated Mothers Against Dpp) activity data show the mmy gene product to be a new type of epidermal BMP regulator – one which transforms a BMP ligand from a long- to a short-range signal. mmy codes for the single UDP-N-acetylglucosamine pyrophosphorylase in Drosophila, and its requirement for attenuating epidermal BMP signaling during dorsal closure points to a new role for glycosylation in defining a highly restricted BMP activity field in the fly. These findings add a new dimension to our understanding of mechanisms modulating the BMP signaling gradient. PMID:23796903

  15. Forces driven by morphogenesis modulate Twist Expression to determine Anterior Mid-gut Differentiation in Drosophila embryos

    NASA Astrophysics Data System (ADS)

    Farge, Emmanuel

    2008-03-01

    By combining magnetic tweezers to in vivo laser ablation, we locally manipulate Drosophila embryonic tissues with physiologically relevant forces. We demonstrate that high level of Twist expression in the stomodeal primordium is mechanically induced in response to compression by the 60±20 nN force developed during germ-band extension (GBE). We find that this force triggers the junctional release and nuclear translocation of Armadillo involved in Twist mechanical induction in the stomodeum in a Src42A dependent way. Finally, stomodeal-specific RNAi-mediated silencing of Twist during compression impairs the differentiation of midgut cells, as revealed by strong defects in Dve expression and abnormal larval lethality. Thus, mechanical induction of Twist overexpression in stomodeal cells is necessary for subsequent midgut differentiation. In collaboration with Nicolas Desprat, Willy Supatto, and Philippe-Alexandre Pouille, MGDET, UMR168 CNRS, Institut Curie11 rue Pierre et Marie Curie, F-75005, Paris, France; and Emmanuel Beaurepaire, LOB, Ecole Polytechnique, CNRS and INSERM U 696, 91128 Palaiseau, France.

  16. Nutrient Sensor in the Brain Directs the Action of the Brain-Gut Axis in Drosophila.

    PubMed

    Dus, Monica; Lai, Jason Sih-Yu; Gunapala, Keith M; Min, Soohong; Tayler, Timothy D; Hergarden, Anne C; Geraud, Eliot; Joseph, Christina M; Suh, Greg S B

    2015-07-01

    Animals can detect and consume nutritive sugars without the influence of taste. However, the identity of the taste-independent nutrient sensor and the mechanism by which animals respond to the nutritional value of sugar are unclear. Here, we report that six neurosecretory cells in the Drosophila brain that produce Diuretic hormone 44 (Dh44), a homolog of the mammalian corticotropin-releasing hormone (CRH), were specifically activated by nutritive sugars. Flies in which the activity of these neurons or the expression of Dh44 was disrupted failed to select nutritive sugars. Manipulation of the function of Dh44 receptors had a similar effect. Notably, artificial activation of Dh44 receptor-1 neurons resulted in proboscis extensions and frequent episodes of excretion. Conversely, reduced Dh44 activity led to decreased excretion. Together, these actions facilitate ingestion and digestion of nutritive foods. We propose that the Dh44 system directs the detection and consumption of nutritive sugars through a positive feedback loop. PMID:26074004

  17. Proper Recruitment of γ-Tubulin and D-TACC/Msps to Embryonic Drosophila Centrosomes Requires Centrosomin Motif 1

    PubMed Central

    Zhang, Jiuli

    2007-01-01

    Centrosomes are microtubule-organizing centers and play a dominant role in assembly of the microtubule spindle apparatus at mitosis. Although the individual binding steps in centrosome maturation are largely unknown, Centrosomin (Cnn) is an essential mitotic centrosome component required for assembly of all other known pericentriolar matrix (PCM) proteins to achieve microtubule-organizing activity at mitosis in Drosophila. We have identified a conserved motif (Motif 1) near the amino terminus of Cnn that is essential for its function in vivo. Cnn Motif 1 is necessary for proper recruitment of γ-tubulin, D-TACC (the homolog of vertebrate transforming acidic coiled-coil proteins [TACC]), and Minispindles (Msps) to embryonic centrosomes but is not required for assembly of other centrosome components including Aurora A kinase and CP60. Centrosome separation and centrosomal satellite formation are severely disrupted in Cnn Motif 1 mutant embryos. However, actin organization into pseudocleavage furrows, though aberrant, remains partially intact. These data show that Motif 1 is necessary for some but not all of the activities conferred on centrosome function by intact Cnn. PMID:17671162

  18. Nutrient Sensor in the Brain Directs the Action of the Brain-Gut Axis in Drosophila

    PubMed Central

    Dus, Monica; Sih-Yu Lai, Jason; Gunapala, Keith M.; Min, Soohong; Tayler, Timothy D.; Hergarden, Anne C.; Geraud, Eliot; Joseph, Christina M.; Suh, Greg S. B.

    2015-01-01

    Summary Animals can detect and consume nutritive sugars without the influence of taste. However, the identity of the taste-independent nutrient sensor and the mechanism by which animals respond to the nutritional value of sugar are unclear. Here, we report that six neurosecretory cells in the Drosophila brain that produce Diuretic hormone 44 (Dh44), a homologue of the mammalian corticotropin-releasing hormone (CRH), were specifically activated by nutritive sugars. Flies in which the activity of these neurons or the expression of Dh44 was disrupted failed to select nutritive sugars. Manipulation of the function of Dh44 receptors had a similar effect. Notably, artificial activation of Dh44 receptor-1 neurons resulted in proboscis extensions, and frequent episodes of excretion. Conversely, reduced Dh44 activity led to decreased excretion. Together, these actions facilitate ingestion and digestion of nutritive foods. We propose that the Dh44 system directs the detection and consumption of nutritive sugars through a positive feedback loop. PMID:26074004

  19. Embryonic Origins of a Motor System:Motor Dendrites Form a Myotopic Mapin Drosophila

    PubMed Central

    2003-01-01

    The organisational principles of locomotor networks are less well understood than those of many sensory systems, where in-growing axon terminals form a central map of peripheral characteristics. Using the neuromuscular system of the Drosophila embryo as a model and retrograde tracing and genetic methods, we have uncovered principles underlying the organisation of the motor system. We find that dendritic arbors of motor neurons, rather than their cell bodies, are partitioned into domains to form a myotopic map, which represents centrally the distribution of body wall muscles peripherally. While muscles are segmental, the myotopic map is parasegmental in organisation. It forms by an active process of dendritic growth independent of the presence of target muscles, proper differentiation of glial cells, or (in its initial partitioning) competitive interactions between adjacent dendritic domains. The arrangement of motor neuron dendrites into a myotopic map represents a first layer of organisation in the motor system. This is likely to be mirrored, at least in part, by endings of higher-order neurons from central pattern-generating circuits, which converge onto the motor neuron dendrites. These findings will greatly simplify the task of understanding how a locomotor system is assembled. Our results suggest that the cues that organise the myotopic map may be laid down early in development as the embryo subdivides into parasegmental units. PMID:14624243

  20. The POU/Oct Transcription Factor Pdm1/nub Is Necessary for a Beneficial Gut Microbiota and Normal Lifespan of Drosophila.

    PubMed

    Dantoft, Widad; Lundin, Daniel; Esfahani, Shiva Seyedoleslami; Engström, Ylva

    2016-01-01

    Maintenance of a stable gut microbial community relies on a delicate balance between immune defense and immune tolerance. We have used Drosophila to study how the microbial gut flora is affected by changes in host genetic factors and immunity. Flies with a constitutively active gut immune system, due to a mutation in the POU transcriptional regulator Pdm1/nubbin (nub) gene, had higher loads of bacteria and a more diverse taxonomic composition than controls. In addition, the microbial composition shifted considerably during the short lifespan of the nub1 mutants. This shift was characterized by a loss of relatively few OTUs (operational taxonomic units) and a remarkable increase in a large number of Acetobacter spp. and Leuconostoc spp. Treating nub1 mutant flies with antibiotics prolonged their lifetime survival by more than 100%. Immune gene expression was also persistently high in the presence of antibiotics, indicating that the early death was not a direct consequence of an overactive immune defense but rather an indirect consequence of the microbial load and composition. Thus, changes in host genotype and an inability to regulate the normal growth and composition of the gut microbiota leads to a shift in the microbial community, dysbiosis and early death. PMID:27231014

  1. Ion permeation properties of the glutamate receptor channel in cultured embryonic Drosophila myotubes.

    PubMed Central

    Chang, H; Ciani, S; Kidokoro, Y

    1994-01-01

    Ion permeation properties of the glutamate receptor channel in cultured myotubes of Drosophila embryos were studied using the inside-out configuration of the patch-clamp technique. Lowering the NaCl concentration in the bath (intracellular solution), while maintaining that of the external solution constant, caused a shift of the reversal potential in the positive direction, thus indicating a higher permeability of the channel to Na+ than to Cl- (PCl/PNa < 0.04), and suggesting that the channel is cation selective. With 145 mM Na+ on both sides of the membrane, the single-channel current-voltage relation was almost linear in the voltage range between -80 and +80 mV, the conductance showing some variability in the range between 140 and 170 pS. All monovalent alkali cations tested, as well as NH4+, permeated the channel effectively. Using the Goldman-Hodgkin-Katz equation for the reversal potential, the permeability ratios with respect to Na+ were estimated to be: 1.32 for K+, 1.18 for NH4+, 1.15 for Rb+, 1.09 for Cs+, and 0.57 for Li+. Divalent cations, i.e. Mg2+ and Ca2+, in the external solution depressed not only the inward but also the outward Na+ currents, although reversal potential measurements indicated that both ions have considerably higher permeabilities than Na+ (PMg/PNa = 2.31; PCa/PNa = 9.55). The conductance-activity relation for Na+ was described by a hyperbolic curve. The maximal conductance was about 195 pS and the half-saturating activity 45 mM. This result suggests that Na+ ions bind to sites in the channel. All data were fitted by a model based on the Eyring's reaction rate theory, in which the receptor channel is a one-ion pore with three energy barriers and two internal sites. PMID:7519261

  2. The Role of Regulated mRNA Stability in Establishing Bicoid Morphogen Gradient in Drosophila Embryonic Development

    PubMed Central

    Liu, Wei; Niranjan, Mahesan

    2011-01-01

    The Bicoid morphogen is amongst the earliest triggers of differential spatial pattern of gene expression and subsequent cell fate determination in the embryonic development of Drosophila. This maternally deposited morphogen is thought to diffuse in the embryo, establishing a concentration gradient which is sensed by downstream genes. In most model based analyses of this process, the translation of the bicoid mRNA is thought to take place at a fixed rate from the anterior pole of the embryo and a supply of the resulting protein at a constant rate is assumed. Is this process of morphogen generation a passive one as assumed in the modelling literature so far, or would available data support an alternate hypothesis that the stability of the mRNA is regulated by active processes? We introduce a model in which the stability of the maternal mRNA is regulated by being held constant for a length of time, followed by rapid degradation. With this more realistic model of the source, we have analysed three computational models of spatial morphogen propagation along the anterior-posterior axis: (a) passive diffusion modelled as a deterministic differential equation, (b) diffusion enhanced by a cytoplasmic flow term; and (c) diffusion modelled by stochastic simulation of the corresponding chemical reactions. Parameter estimation on these models by matching to publicly available data on spatio-temporal Bicoid profiles suggests strong support for regulated stability over either a constant supply rate or one where the maternal mRNA is permitted to degrade in a passive manner. PMID:21949782

  3. The Homeotic Gene Sex Combs Reduced of Drosophila Melanogaster Is Differentially Regulated in the Embryonic and Imaginal Stages of Development

    PubMed Central

    Pattatucci, A. M.; Kaufman, T. C.

    1991-01-01

    The Sex combs reduced (Scr) locus is unique among the genes contained within the Antennapedia complex (ANT-C) of Drosophila melanogaster in that it directs functions that are required for both cephalic and thoracic development in the embryo and the adult. Antibodies raised against protein encoded by Scr were used to follow the distribution of this gene product in embryos and imaginal discs of third instar larvae. Analysis of Scr protein accumulation in embryos hemizygous for breakpoint lesions mapping throughout the locus has allowed us to determine that sequences required for establishment of the Scr embryonic pattern are contained within a region of DNA that overlaps with the identified upstream regulatory region of the segmentation gene fushi tarazu (ftz). Gain-of-function mutations in Scr result in the presence of ectopic sex comb teeth on the first tarsal segment of mesothoracic and metathoracic legs of adult males. Heterozygous combinations of gain-of-function alleles with a wild-type Scr gene exhibit no evidence of ectopic protein localization in the second and third thoracic segments of embryos. However, mesothoracic and metathoracic leg imaginal discs can be shown to accumulate ectopically expressed Scr protein, implying a differential regulation of the Scr gene during these two periods of development. Additionally, we have found that the spatial pattern of Scr gene expression in imaginal tissues involved in the development of the adult thorax is governed in part by synapsis of homologous chromosomes in this region of the ANT-C. However, those imaginal discs that arise anteriorly to the prothorax do not appear to be sensitive to this form of gene regulation. Finally, we have demonstrated that the extent of Scr expression is influenced by mutations at the Polycomb (Pc) locus but not by mutant alleles of the zeste (z) gene. Taken together, our data suggests that Scr gene expression is differentially regulated both temporally and spatially in a manner that is

  4. Drosophila coracle, a Member of the Protein 4.1 Superfamily, Has Essential Structural Functions in the Septate Junctions and Developmental Functions in Embryonic and Adult Epithelial Cells

    PubMed Central

    Lamb, Rebecca S.; Ward, Robert E.; Schweizer, Liang; Fehon, Richard G.

    1998-01-01

    Although extensively studied biochemically, members of the Protein 4.1 superfamily have not been as well characterized genetically. Studies of coracle, a Drosophila Protein 4.1 homologue, provide an opportunity to examine the genetic functions of this gene family. coracle was originally identified as a dominant suppressor of EgfrElp, a hypermorphic form of the Drosophila Epidermal growth factor receptor gene. In this article, we present a phenotypic analysis of coracle, one of the first for a member of the Protein 4.1 superfamily. Screens for new coracle alleles confirm the null coracle phenotype of embryonic lethality and failure in dorsal closure, and they identify additional defects in the embryonic epidermis and salivary glands. Hypomorphic coracle alleles reveal functions in many imaginal tissues. Analysis of coracle mutant cells indicates that Coracle is a necessary structural component of the septate junction required for the maintenance of the transepithelial barrier but is not necessary for apical–basal polarity, epithelial integrity, or cytoskeletal integrity. In addition, coracle phenotypes suggest a specific role in cell signaling events. Finally, complementation analysis provides information regarding the functional organization of Coracle and possibly other Protein 4.1 superfamily members. These studies provide insights into a range of in vivo functions for coracle in developing embryos and adults. PMID:9843584

  5. Passive Stiffness in Drosophila Indirect Flight Muscle Reduced by Disrupting Paramyosin Phosphorylation, but Not by Embryonic Myosin S2 Hinge Substitution

    PubMed Central

    Hao, Yudong; Miller, Mark S.; Swank, Douglas M.; Liu, Hongjun; Bernstein, Sanford I.; Maughan, David W.; Pollack, Gerald H.

    2006-01-01

    High passive stiffness is one of the characteristic properties of the asynchronous indirect flight muscle (IFM) found in many insects like Drosophila. To evaluate the effects of two thick filament protein domains on passive sarcomeric stiffness, and to investigate their correlation with IFM function, we used microfabricated cantilevers and a high resolution imaging system to study the passive IFM myofibril stiffness of two groups of transgenic Drosophila lines. One group (hinge-switch mutants) had a portion of the endogenous S2 hinge region replaced by an embryonic version; the other group (paramyosin mutants) had one or more putative phosphorylation sites near the N-terminus of paramyosin disabled. Both transgenic groups showed severely compromised flight ability. In this study, we found no difference (compared to the control) in passive elastic modulus in the hinge-switch group, but a 15% reduction in the paramyosin mutants. All results were corroborated by muscle fiber mechanics experiments performed on the same lines. The fact that myofibril elasticity is unaffected by hinge switching implies alternative S2 hinges do not critically affect passive sarcomere stiffness. In contrast, the mechanical defects observed upon disrupting paramyosin phosphorylation sites in Drosophila suggests that paramyosin phosphorylation is important for maintaining high passive stiffness in IFM myofibrils, probably by affecting paramyosin's interaction with other sarcomeric proteins. PMID:17012313

  6. Chromatin architecture of the Pitx2 locus requires CTCF and Pitx2 dependent asymmetry that mirrors embryonic gut laterality

    PubMed Central

    Welsh, Ian C.; Kwak, Hojoong; Chen, Frances L.; Werner, Melissa; Shopland, Lindsay S.; Danko, Charles G.; Lis, John T.; Zhang, Min; Martin, James F.; Kurpios, Natasza A.

    2015-01-01

    Summary Expression of Pitx2 on the left side of the embryo patterns left-right (LR) organs including the dorsal mesentery (DM), whose asymmetric cell behavior directs gut looping. Despite the importance of organ laterality, chromatin-level regulation of Pitx2 remains undefined. Here we show that genes immediately neighboring Pitx2 in chicken and mouse, including a long noncoding RNA, Playrr (Pitx2 locus asymmetric regulated RNA), are expressed on the right side and repressed by Pitx2. CRISPR/Cas9 genome editing of Playrr, 3D fluorescent in situ hybridization (FISH) and variations of chromatin conformation capture (3C), demonstrate that mutual antagonism between Pitx2 and Playrr is coordinated by asymmetric chromatin interactions dependent on Pitx2 and CTCF. We demonstrate that transcriptional and morphological asymmetries driving gut looping are mirrored by chromatin architectural asymmetries at the Pitx2 locus. We propose a model where Pitx2 auto-regulation directs chromatin topology to coordinate LR transcription of this locus essential for LR organogenesis. PMID:26411685

  7. A new method for detection and quantification of heartbeat parameters in Drosophila, zebrafish, and embryonic mouse hearts

    PubMed Central

    Fink, Martin; Callol-Massot, Carles; Chu, Angela; Ruiz-Lozano, Pilar; Belmonte, Juan Carlos Izpisua; Giles, Wayne; Bodmer, Rolf; Ocorr, Karen

    2010-01-01

    The genetic basis of heart development is remarkably conserved from Drosophila to mammals, and insights from flies have greatly informed our understanding of vertebrate heart development. Recent evidence suggests that many aspects of heart function are also conserved and the genes involved in heart development also play roles in adult heart function. We have developed a Drosophila heart preparation and movement analysis algorithm that allows quantification of functional parameters. Our methodology combines high-speed optical recording of beating hearts with a robust, semi-automated analysis to accurately detect and quantify, on a beat-to-beat basis, not only heart rate but also diastolic and systolic intervals, systolic and diastolic diameters, percent fractional shortening, contraction wave velocity, and cardiac arrhythmicity. Here, we present a detailed analysis of hearts from adult Drosophila, 2–3-day-old zebrafish larva, and 8-day-old mouse embryos, indicating that our methodology is potentially applicable to an array of biological models. We detect progressive age-related changes in fly hearts as well as subtle but distinct cardiac deficits in Tbx5 heterozygote mutant zebrafish. Our methodology for quantifying cardiac function in these genetically tractable model systems should provide valuable insights into the genetics of heart function. PMID:19317655

  8. Src family kinases are required for WNT5 signaling through the Derailed/RYK receptor in the Drosophila embryonic central nervous system.

    PubMed

    Wouda, Rene R; Bansraj, Monique R K S; de Jong, Anja W M; Noordermeer, Jasprina N; Fradkin, Lee G

    2008-07-01

    Members of the RYK/Derailed family have recently been shown to regulate axon guidance in both Drosophila and mammals by acting as Wnt receptors. Little is known about how the kinase activity-deficient RYKs transduce Wnt signals. Here, we show that the non-receptor Src family tyrosine kinases, SRC64B and SRC42A, are involved in WNT5-mediated signaling through Derailed in the Drosophila embryonic central nervous system. Analysis of animals lacking SRC64B and SRC42A reveals defects in commissure formation similar to those observed in Wnt5 and derailed mutants. Reductions in SRC64B expression levels suppress a Wnt5/derailed-dependent dominant gain-of-function phenotype, and increased levels of either SRC64B or SRC42A enhance Wnt5/derailed-mediated axon commissure switching. Derailed and SRC64B form a complex, which contains catalytically active SRC64B, the formation or stability of which requires SRC64B kinase activity. Furthermore, Derailed is phosphorylated in a SRC64B-dependent manner and coexpression of Derailed and SRC64B results in the activation of SRC64B. The mammalian orthologs of Derailed and SRC64B also form complexes, suggesting that Src roles in RYK signaling are conserved. Finally, we show that coexpression of WNT5 and Derailed has no apparent effect upon TCF/LEF-dependent transcription, suggesting that the WNT5/Derailed signaling pathway is unlikely to directly regulate canonical Wnt pathway targets. Together, these findings indicate that the Src family kinases play novel roles in WNT5/Derailed-mediated signaling. PMID:18539923

  9. The myogenic repressor gene Holes in muscles is a direct transcriptional target of Twist and Tinman in the Drosophila embryonic mesoderm

    PubMed Central

    Elwell, Jennifer A.; Lovato, TyAnna L.; Adams, Melanie M.; Baca, Erica M.; Lee, Thai; Cripps, Richard M.

    2015-01-01

    Understanding the regulatory circuitry controlling myogenesis is critical to understanding developmental mechanisms and developmentally-derived diseases. We analyzed the transcriptional regulation of a Drosophila myogenic repressor gene, Holes in muscles (Him). Previously, Him was shown to inhibit Myocyte enhancer factor-2 (MEF2) activity, and is expressed in myoblasts but not differentiating myotubes. We demonstrate that different phases of Him embryonic expression arise through the actions of different enhancers, and we characterize the enhancer required for its early mesoderm expression. This Him early mesoderm enhancer contains two conserved binding sites for the basic helix-loop-helix regulator Twist, and one binding site for the NK homeodomain protein Tinman. The sites for both proteins are required for enhancer activity in early embryos. Twist and Tinman activate the enhancer in tissue culture assays, and ectopic expression of either factor is sufficient to direct ectopic expression of a Him-lacZ reporter, or of the endogenous Him gene. Moreover, sustained expression of twist expression in the mesoderm up-regulates mesodermal Him expression in late embryos. Our findings provide a model to define mechanistically how Twist can both promotes myogenesis through direct activation of Mef2, and can place a brake on myogenesis, through direct activation of Him. PMID:25704510

  10. The FHA domain determines Drosophila Chk2/Mnk localization to key mitotic structures and is essential for early embryonic DNA damage responses.

    PubMed

    Takada, Saeko; Collins, Eric R; Kurahashi, Kayo

    2015-05-15

    DNA damage responses, including mitotic centrosome inactivation, cell-cycle delay in mitosis, and nuclear dropping from embryo cortex, maintain genome integrity in syncytial Drosophila embryos. A conserved signaling kinase, Chk2, known as Mnk/Loki, is essential for the responses. Here we demonstrate that functional EGFP-Mnk expressed from a transgene localizes to the nucleus, centrosomes, interkinetochore/centromere region, midbody, and pseudocleavage furrows without DNA damage and in addition forms numerous foci/aggregates on mitotic chromosomes upon DNA damage. We expressed EGFP-tagged Mnk deletion or point mutation variants and investigated domain functions of Mnk in vivo. A triple mutation in the phosphopeptide-binding site of the forkhead-associated (FHA) domain disrupted normal Mnk localization except to the nucleus. The mutation also disrupted Mnk foci formation on chromosomes upon DNA damage. FHA mutations and deletion of the SQ/TQ-cluster domain (SCD) abolished Mnk transphosphorylations and autophosphorylations, indicative of kinase activation after DNA damage. A potent NLS was found at the C-terminus, which is required for normal Mnk function. We propose that the FHA domain in Mnk plays essential dual functions in mediating embryonic DNA damage responses by means of its phosphopeptide-binding ability: activating Mnk in the nucleus upon DNA damage and recruiting Mnk to multiple subcellular structures independently of DNA damage. PMID:25808488

  11. Germ line and embryonic expression of Fex, a member of the Drosophila F-element retrotransposon family, is mediated by an internal cis-regulatory control region.

    PubMed Central

    Kerber, B; Fellert, S; Taubert, H; Hoch, M

    1996-01-01

    The F elements of Drosophila melanogaster belong to the superfamily of long interspersed nucleotide element retrotransposons. To date, F-element transcription has not been detected in flies. Here we describe the isolation of a member of the F-element family, termed Fex, which is transcribed in specific cells of the female and male germ lines and in various tissues during embryogenesis of D. melanogaster. Sequence analysis revealed that this element contains two complete open reading frames coding for a putative nucleic acid-binding protein and a putative reverse transcriptase. Functional analysis of the 5' region, using germ line transformation of Fex-lacZ reporter gene constructs, demonstrates that major aspects of tissue-specific Fex expression are controlled by internal cis-acting elements that lie in the putative coding region of open reading frame 1. These sequences mediate dynamic gene expression in eight expression domains during embryonic and germ line development. The capacity of the cis-regulatory region of the Fex element to mediate such complex expression patterns is unique among members of the long interspersed nucleotide element superfamily of retrotransposons and is reminiscent of regulatory regions of developmental control genes. PMID:8649411

  12. The FHA domain determines Drosophila Chk2/Mnk localization to key mitotic structures and is essential for early embryonic DNA damage responses

    PubMed Central

    Takada, Saeko; Collins, Eric R.; Kurahashi, Kayo

    2015-01-01

    DNA damage responses, including mitotic centrosome inactivation, cell-cycle delay in mitosis, and nuclear dropping from embryo cortex, maintain genome integrity in syncytial Drosophila embryos. A conserved signaling kinase, Chk2, known as Mnk/Loki, is essential for the responses. Here we demonstrate that functional EGFP-Mnk expressed from a transgene localizes to the nucleus, centrosomes, interkinetochore/centromere region, midbody, and pseudocleavage furrows without DNA damage and in addition forms numerous foci/aggregates on mitotic chromosomes upon DNA damage. We expressed EGFP-tagged Mnk deletion or point mutation variants and investigated domain functions of Mnk in vivo. A triple mutation in the phosphopeptide-binding site of the forkhead-associated (FHA) domain disrupted normal Mnk localization except to the nucleus. The mutation also disrupted Mnk foci formation on chromosomes upon DNA damage. FHA mutations and deletion of the SQ/TQ-cluster domain (SCD) abolished Mnk transphosphorylations and autophosphorylations, indicative of kinase activation after DNA damage. A potent NLS was found at the C-terminus, which is required for normal Mnk function. We propose that the FHA domain in Mnk plays essential dual functions in mediating embryonic DNA damage responses by means of its phosphopeptide-binding ability: activating Mnk in the nucleus upon DNA damage and recruiting Mnk to multiple subcellular structures independently of DNA damage. PMID:25808488

  13. Lineage-specific effects of Notch/Numb signaling in post-embryonic development of the Drosophila brain.

    PubMed

    Lin, Suewei; Lai, Sen-Lin; Yu, Huang-Hsiang; Chihara, Takahiro; Luo, Liqun; Lee, Tzumin

    2010-01-01

    Numb can antagonize Notch signaling to diversify the fates of sister cells. We report here that paired sister cells acquire different fates in all three Drosophila neuronal lineages that make diverse types of antennal lobe projection neurons (PNs). Only one in each pair of postmitotic neurons survives into the adult stage in both anterodorsal (ad) and ventral (v) PN lineages. Notably, Notch signaling specifies the PN fate in the vPN lineage but promotes programmed cell death in the missing siblings in the adPN lineage. In addition, Notch/Numb-mediated binary sibling fates underlie the production of PNs and local interneurons from common precursors in the lAL lineage. Furthermore, Numb is needed in the lateral but not adPN or vPN lineages to prevent the appearance of ectopic neuroblasts and to ensure proper self-renewal of neural progenitors. These lineage-specific outputs of Notch/Numb signaling show that a universal mechanism of binary fate decision can be utilized to govern diverse neural sibling differentiations. PMID:20023159

  14. RanGTP is required for meiotic spindle organization and the initiation of embryonic development in Drosophila

    PubMed Central

    Cesario, J.; McKim, K. S.

    2011-01-01

    RanGTP is important for chromosome-dependent spindle assembly in Xenopus extracts. Here we report on experiments to determine the role of the Ran pathway on microtubule dynamics in Drosophila oocytes and embryos. Females expressing a dominant-negative form of Ran have fertility defects, suggesting that RanGTP is required for normal fertility. This is not, however, because of a defect in acentrosomal meiotic spindle assembly. Therefore, RanGTP does not appear to be essential or sufficient for the formation of the acentrosomal spindle. Instead, the most important function of the Ran pathway in spindle assembly appears to be in the tapering of microtubules at the spindle poles, which might be through regulation of proteins such as TACC and the HURP homolog, Mars. One consequence of this spindle organization defect is an increase in the nondisjunction of achiasmate chromosomes. However, the meiotic defects are not severe enough to cause the decreased fertility. Reductions in fertility occur because RanGTP has a role in microtubule assembly that is not directly nucleated by the chromosomes. This includes microtubules nucleated from the sperm aster, which are required for pronuclear fusion. We propose that following nuclear envelope breakdown, RanGTP is released from the nucleus and creates a cytoplasm that is activated for assembling microtubules, which is important for processes such as pronuclear fusion. Around the chromosomes, however, RanGTP might be redundant with other factors such as the chromosome passenger complex. PMID:22100918

  15. Planar cell polarity: the Dachsous/Fat system contributes differently to the embryonic and larval stages of Drosophila

    PubMed Central

    Saavedra, Pedro; Brittle, Amy; Palacios, Isabel M.; Strutt, David; Casal, José; Lawrence, Peter A.

    2016-01-01

    ABSTRACT The epidermal patterns of all three larval instars (L1–L3) of Drosophila are made by one unchanging set of cells. The seven rows of cuticular denticles of all larval stages are consistently planar polarised, some pointing forwards, others backwards. In L1 all the predenticles originate at the back of the cells but, in L2 and L3, they form at the front or the back of the cell depending on the polarity of the forthcoming denticles. We find that, to polarise all rows, the Dachsous/Fat system is differentially utilised; in L1 it is active in the placement of the actin-based predenticles but is not crucial for the final orientation of the cuticular denticles, in L2 and L3 it is needed for placement and polarity. We find Four-jointed to be strongly expressed in the tendon cells and show how this might explain the orientation of all seven rows. Unexpectedly, we find that L3 that lack Dachsous differ from larvae lacking Fat and we present evidence that this is due to differently mislocalised Dachs. We make some progress in understanding how Dachs contributes to phenotypes of wildtype and mutant larvae and adults. PMID:26935392

  16. Gene expression profiles uncover individual identities of gnathal neuroblasts and serial homologies in the embryonic CNS of Drosophila

    PubMed Central

    Urbach, Rolf; Jussen, David; Technau, Gerhard M.

    2016-01-01

    The numbers and types of progeny cells generated by neural stem cells in the developing CNS are adapted to its region-specific functional requirements. In Drosophila, segmental units of the CNS develop from well-defined patterns of neuroblasts. Here we constructed comprehensive neuroblast maps for the three gnathal head segments. Based on the spatiotemporal pattern of neuroblast formation and the expression profiles of 46 marker genes (41 transcription factors), each neuroblast can be uniquely identified. Compared with the thoracic ground state, neuroblast numbers are progressively reduced in labial, maxillary and mandibular segments due to smaller sizes of neuroectodermal anlagen and, partially, to suppression of neuroblast formation and induction of programmed cell death by the Hox gene Deformed. Neuroblast patterns are further influenced by segmental modifications in dorsoventral and proneural gene expression. With the previously published neuroblast maps and those presented here for the gnathal region, all neuroectodermal neuroblasts building the CNS of the fly (ventral nerve cord and brain, except optic lobes) are now individually identified (in total 2×567 neuroblasts). This allows, for the first time, a comparison of the characteristics of segmental populations of stem cells and to screen for serially homologous neuroblasts throughout the CNS. We show that approximately half of the deutocerebral and all of the tritocerebral (posterior brain) and gnathal neuroblasts, but none of the protocerebral (anterior brain) neuroblasts, display serial homology to neuroblasts in thoracic/abdominal neuromeres. Modifications in the molecular signature of serially homologous neuroblasts are likely to determine the segment-specific characteristics of their lineages. PMID:27095493

  17. P-Element Insertion Alleles of Essential Genes on the Third Chromosome of Drosophila Melanogaster: Mutations Affecting Embryonic Pns Development

    PubMed Central

    Salzberg, A.; Prokopenko, S. N.; He, Y.; Tsai, P.; Pal, M.; Maroy, P.; Glover, D. M.; Deak, P.; Bellen, H. J.

    1997-01-01

    To identify novel genes and to isolate tagged mutations in known genes that are required for the development of the peripheral nervous system (PNS), we have screened a novel collection of 2460 strains carrying lethal or semilethal P-element insertions on the third chromosome. Monoclonal antibody 22C10 was used as a marker to visualize the embryonic PNS. We identified 109 mutant strains that exhibited reproducible phenotypes in the PNS. Cytological and genetic analyses of these strains indicated that 87 mutations affect previously identified genes: tramtrack (n = 18 alleles), string (n = 15), cyclin A (n = 13), single-minded (n = 13), Delta (n = 9), neuralized (n = 4), pointed (n = 4), extra macrochaetae (n = 4), prospero (n = 3), tartan (n = 2), and pebble (n = 2). In addition, 13 mutations affect genes that we identified recently in a chemical mutagenesis screen designed to isolate similar mutants: hearty (n = 3), dorsotonals (n = 2), pavarotti (n = 2), sanpodo (n = 2), dalmatian (n = 1), missensed (n = 1), senseless (n = 1), and sticky ch1 (n = 1). The remaining nine mutations define seven novel complementation groups. The data presented here demonstrate that this collection of P elements will be useful for the identification and cloning of novel genes on the third chromosome, since >70% of mutations identified in the screen are caused by the insertion of a P element. A comparison between this screen and a chemical mutagenesis screen undertaken earlier highlights the complementarity of the two types of genetic screens. PMID:9409832

  18. Cell-Autonomous and Non-cell-autonomous Function of Hox Genes Specify Segmental Neuroblast Identity in the Gnathal Region of the Embryonic CNS in Drosophila

    PubMed Central

    Becker, Henrike; Renner, Simone; Technau, Gerhard M.; Berger, Christian

    2016-01-01

    During central nervous system (CNS) development neural stem cells (Neuroblasts, NBs) have to acquire an identity appropriate to their location. In thoracic and abdominal segments of Drosophila, the expression pattern of Bithorax-Complex Hox genes is known to specify the segmental identity of NBs prior to their delamination from the neuroectoderm. Compared to the thoracic, ground state segmental units in the head region are derived to different degrees, and the precise mechanism of segmental specification of NBs in this region is still unclear. We identified and characterized a set of serially homologous NB-lineages in the gnathal segments and used one of them (NB6-4 lineage) as a model to investigate the mechanism conferring segment-specific identities to gnathal NBs. We show that NB6-4 is primarily determined by the cell-autonomous function of the Hox gene Deformed (Dfd). Interestingly, however, it also requires a non-cell-autonomous function of labial and Antennapedia that are expressed in adjacent anterior or posterior compartments. We identify the secreted molecule Amalgam (Ama) as a downstream target of the Antennapedia-Complex Hox genes labial, Dfd, Sex combs reduced and Antennapedia. In conjunction with its receptor Neurotactin (Nrt) and the effector kinase Abelson tyrosine kinase (Abl), Ama is necessary in parallel to the cell-autonomous Dfd pathway for the correct specification of the maxillary identity of NB6-4. Both pathways repress CyclinE (CycE) and loss of function of either of these pathways leads to a partial transformation (40%), whereas simultaneous mutation of both pathways leads to a complete transformation (100%) of NB6-4 segmental identity. Finally, we provide genetic evidences, that the Ama-Nrt-Abl-pathway regulates CycE expression by altering the function of the Hippo effector Yorkie in embryonic NBs. The disclosure of a non-cell-autonomous influence of Hox genes on neural stem cells provides new insight into the process of segmental

  19. Cell-Autonomous and Non-cell-autonomous Function of Hox Genes Specify Segmental Neuroblast Identity in the Gnathal Region of the Embryonic CNS in Drosophila.

    PubMed

    Becker, Henrike; Renner, Simone; Technau, Gerhard M; Berger, Christian

    2016-03-01

    During central nervous system (CNS) development neural stem cells (Neuroblasts, NBs) have to acquire an identity appropriate to their location. In thoracic and abdominal segments of Drosophila, the expression pattern of Bithorax-Complex Hox genes is known to specify the segmental identity of NBs prior to their delamination from the neuroectoderm. Compared to the thoracic, ground state segmental units in the head region are derived to different degrees, and the precise mechanism of segmental specification of NBs in this region is still unclear. We identified and characterized a set of serially homologous NB-lineages in the gnathal segments and used one of them (NB6-4 lineage) as a model to investigate the mechanism conferring segment-specific identities to gnathal NBs. We show that NB6-4 is primarily determined by the cell-autonomous function of the Hox gene Deformed (Dfd). Interestingly, however, it also requires a non-cell-autonomous function of labial and Antennapedia that are expressed in adjacent anterior or posterior compartments. We identify the secreted molecule Amalgam (Ama) as a downstream target of the Antennapedia-Complex Hox genes labial, Dfd, Sex combs reduced and Antennapedia. In conjunction with its receptor Neurotactin (Nrt) and the effector kinase Abelson tyrosine kinase (Abl), Ama is necessary in parallel to the cell-autonomous Dfd pathway for the correct specification of the maxillary identity of NB6-4. Both pathways repress CyclinE (CycE) and loss of function of either of these pathways leads to a partial transformation (40%), whereas simultaneous mutation of both pathways leads to a complete transformation (100%) of NB6-4 segmental identity. Finally, we provide genetic evidences, that the Ama-Nrt-Abl-pathway regulates CycE expression by altering the function of the Hippo effector Yorkie in embryonic NBs. The disclosure of a non-cell-autonomous influence of Hox genes on neural stem cells provides new insight into the process of segmental

  20. Coordination of insulin and Notch pathway activities by microRNA miR-305 mediates adaptive homeostasis in the intestinal stem cells of the Drosophila gut

    PubMed Central

    Foronda, David; Weng, Ruifen; Verma, Pushpa; Chen, Ya-Wen

    2014-01-01

    Homeostasis of the intestine is maintained by dynamic regulation of a pool of intestinal stem cells. The balance between stem cell self-renewal and differentiation is regulated by the Notch and insulin signaling pathways. Dependence on the insulin pathway places the stem cell pool under nutritional control, allowing gut homeostasis to adapt to environmental conditions. Here we present evidence that miR-305 is required for adaptive homeostasis of the gut. miR-305 regulates the Notch and insulin pathways in the intestinal stem cells. Notably, miR-305 expression in the stem cells is itself under nutritional control via the insulin pathway. This link places regulation of Notch pathway activity under nutritional control. These findings provide a mechanism through which the insulin pathway controls the balance between stem cell self-renewal and differentiation that is required for adaptive homeostasis in the gut in response to changing environmental conditions. PMID:25367037

  1. Loss of function of the Drosophila Ninein-related centrosomal protein Bsg25D causes mitotic defects and impairs embryonic development.

    PubMed

    Kowanda, Michelle; Bergalet, Julie; Wieczorek, Michal; Brouhard, Gary; Lécuyer, Éric; Lasko, Paul

    2016-01-01

    The centrosome-associated proteins Ninein (Nin) and Ninein-like protein (Nlp) play significant roles in microtubule stability, nucleation and anchoring at the centrosome in mammalian cells. Here, we investigate Blastoderm specific gene 25D (Bsg25D), which encodes the only Drosophila protein that is closely related to Nin and Nlp. In early embryos, we find that Bsg25D mRNA and Bsg25D protein are closely associated with centrosomes and astral microtubules. We show that sequences within the coding region and 3'UTR of Bsg25D mRNAs are important for proper localization of this transcript in oogenesis and embryogenesis. Ectopic expression of eGFP-Bsg25D from an unlocalized mRNA disrupts microtubule polarity in mid-oogenesis and compromises the distribution of the axis polarity determinant Gurken. Using total internal reflection fluorescence microscopy, we show that an N-terminal fragment of Bsg25D can bind microtubules in vitro and can move along them, predominantly toward minus-ends. While flies homozygous for a Bsg25D null mutation are viable and fertile, 70% of embryos lacking maternal and zygotic Bsg25D do not hatch and exhibit chromosome segregation defects, as well as detachment of centrosomes from mitotic spindles. We conclude that Bsg25D is a centrosomal protein that, while dispensable for viability, nevertheless helps ensure the integrity of mitotic divisions in Drosophila. PMID:27422905

  2. Drosophila RhoGEF4 encodes a novel RhoA-specific guanine exchange factor that is highly expressed in the embryonic central nervous system.

    PubMed

    Nahm, Minyeop; Lee, Mihye; Baek, Seung-Hak; Yoon, Jin-Ho; Kim, Hong-Hee; Lee, Zang Hee; Lee, Seungbok

    2006-12-15

    Rho family small GTPases act as molecular switches that regulate neuronal morphogenesis, including axon growth and guidance, dendritic spine formation, and synapse formation. These proteins are positively regulated by guanine nucleotide exchange factors (GEFs) of the Dbl family. This study describes the identification and characterization of Drosophila RhoGEF4 (DRhoGEF4), a novel Dbl family protein that is specifically expressed in the central nervous system during Drosophila embryogenesis. The predicted amino acid sequence of DRhoGEF4 contains a Dbl homology (DH) domain and an adjacent C-terminal pleckstrin homology (PH) domain, which are most closely related to those of mammalian frabins. In this study, the DH-PH motif is shown to enhance the dissociation of GDP from either RhoA or Rac1 but not from Cdc42 in vitro. In addition, p21-binding domain pull-down assays demonstrate that DRhoGEF4 activates RhoA, but neither Rac1 nor Cdc42 in HEK293 cells. Finally, overexpression of DRhoGEF4 is able to induce assembly of stress fibers in cultured NIH3T3 cells. Taken together, these findings suggest that DRhoGEF4 may participate in cytoskeleton-related cellular events by specifically activating RhoA in neuronal morphogenesis. PMID:17011730

  3. Loss of function of the Drosophila Ninein-related centrosomal protein Bsg25D causes mitotic defects and impairs embryonic development

    PubMed Central

    Kowanda, Michelle; Bergalet, Julie; Wieczorek, Michal; Brouhard, Gary; Lécuyer, Éric

    2016-01-01

    ABSTRACT The centrosome-associated proteins Ninein (Nin) and Ninein-like protein (Nlp) play significant roles in microtubule stability, nucleation and anchoring at the centrosome in mammalian cells. Here, we investigate Blastoderm specific gene 25D (Bsg25D), which encodes the only Drosophila protein that is closely related to Nin and Nlp. In early embryos, we find that Bsg25D mRNA and Bsg25D protein are closely associated with centrosomes and astral microtubules. We show that sequences within the coding region and 3′UTR of Bsg25D mRNAs are important for proper localization of this transcript in oogenesis and embryogenesis. Ectopic expression of eGFP-Bsg25D from an unlocalized mRNA disrupts microtubule polarity in mid-oogenesis and compromises the distribution of the axis polarity determinant Gurken. Using total internal reflection fluorescence microscopy, we show that an N-terminal fragment of Bsg25D can bind microtubules in vitro and can move along them, predominantly toward minus-ends. While flies homozygous for a Bsg25D null mutation are viable and fertile, 70% of embryos lacking maternal and zygotic Bsg25D do not hatch and exhibit chromosome segregation defects, as well as detachment of centrosomes from mitotic spindles. We conclude that Bsg25D is a centrosomal protein that, while dispensable for viability, nevertheless helps ensure the integrity of mitotic divisions in Drosophila. PMID:27422905

  4. Expression patterns of two murine homologs of Drosophila single-minded suggest possible roles in embryonic patterning and in the pathogenesis of Down syndrome.

    PubMed

    Fan, C M; Kuwana, E; Bulfone, A; Fletcher, C F; Copeland, N G; Jenkins, N A; Crews, S; Martinez, S; Puelles, L; Rubenstein, J L; Tessier-Lavigne, M

    1996-01-01

    The single-minded (sim) gene encodes a transcriptional regulator that functions as a key determinant of central nervous system (CNS) midline development in Drosophila. We report here the identification of two murine homologs of sim, Sim1 and Sim2, whose products show a high degree of sequence conservation with Drosophila SIM in their amino-terminal halves, with each containing a basic helix-loop-helix domain as well as a PAS domain. Sim1 maps to the proximal region of mouse chromosome 10, whereas Sim2 maps to a portion of the distal end of chromosome 16 that is syntenic to the Down syndrome critical region of human chromosome 21. Recent exon-trapping studies have identified in the critical region several exons of a human sim homolog which appears to be the homolog of murine Sim2; this has led to the hypothesis that increased dosage of this sim homolog in cases of trisomy 21 might be a causal factor in the pathogenesis of Down syndrome. We have examined the expression patterns of the Sim genes during embryogenesis. Both genes are expressed in dynamic and selective fashion in specific neuromeric compartments of the developing forebrain, and the expression pattern of Sim2 provides evidence for early regionalization of the diencephalon prior to any overt morphological differentiation in this region. Outside the CNS, Sim1 is expressed in mesodermal and endodermal tissues, including developing somites, mesonephric duct, and foregut. Sim2 is expressed in facial and trunk cartilage, as well as trunk muscles. Both murine Sim genes are also expressed in the developing kidney. Our data suggest that the Sim genes play roles in directing the regionalization of tissues where they are expressed. Moreover, the expression pattern documented for Sim2 may provide insights into its potential roles in Down syndrome. PMID:8812055

  5. The multilayered innate immune defense of the gut.

    PubMed

    El Chamy, Laure; Matt, Nicolas; Ntwasa, Monde; Reichhart, Jean-Marc

    2015-01-01

    In the wild, the fruit fly Drosophila melanogaster thrives on rotten fruit. The digestive tract maintains a powerful gut immune barrier to regulate the ingested microbiota, including entomopathogenic bacteria. This gut immune barrier includes a chitinous peritrophic matrix that isolates the gut contents from the epithelial cells. In addition, the epithelial cells are tightly sealed by septate junctions and can mount an inducible immune response. This local response can be activated by invasive bacteria, or triggered by commensal bacteria in the gut lumen. As with chronic inflammation in mammals, constitutive activation of the gut innate immune response is detrimental to the health of flies. Accordingly, the Drosophila gut innate immune response is tightly regulated to maintain the endogenous microbiota, while preventing infections by pathogenic microorganisms. PMID:26068126

  6. Developmental expression pattern of D-ets4, the Drosophila homologue of human Pdef.

    PubMed

    Hsouna, Anita; Watson, Dennis K; Hsu, Tien

    2004-12-01

    Primordial germ cells (PGCs) are the first cells specified in many organisms. In Drosophila, as in mammals, PGCs are formed at the posterior end outside of the embryonic proper. They are brought into the gut during gastrulation and then actively migrate through the gut epithelium into the mesoderm. They attach to the future gonadal mesoderm and coalesce, forming the gonads. Control of this migratory process is not yet completely understood. D-ets4 and its mammalian homologue Pdef are members of the evolutionarily conserved Ets family of transcription factors. Pdef has been shown to down-regulate the invasive and migratory potential of breast tumors. Our results show that the Drosophila D-ets4 protein is specifically expressed in PGCs before the onset of migration and is lost in the migratory and post-migratory PGCs. We also show that D-ets4 is not involved in other migratory events such as border cell migration during oogenesis. It is, however, expressed strongly in the pre-stage 10 oocyte nuclei and modestly in larval tissues such as imaginal discs and salivary glands, but not in the brain. PMID:15567727

  7. Crystallization of Spätzle, a cystine-knot protein involved in embryonic development and innate immunity in Drosophila melanogaster

    SciTech Connect

    Hoffmann, Anita; Neumann, Piotr; Schierhorn, Angelika; Stubbs, Milton T.

    2008-08-01

    Crystallization of the cystine-knot protein Spätzle occurred following serendipitous limited degradation of the pro-Spätzle propeptide during the crystallization experiment. The Spätzle protein is involved in both the definition of the dorsal–ventral axis during embryonic development and in the adult innate immune response. The disulfide-linked dimeric cystine-knot protein has been expressed as a proprotein in inclusion bodies in Escherichia coli and refolded in vitro by rapid dilution. Initial orthorhombic crystals that diffracted to 7 Å resolution were obtained after three months by the sitting-drop vapour-diffusion method. Optimization of the crystallization conditions resulted in orthorhombic crystals (space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 53.0, b = 59.2, c = 62.5 Å) that diffracted to 2.8 Å resolution in-house. The small volume of the asymmetric unit indicated that it was not possible for the crystals to contain the complete pro-Spätzle dimer. Mass spectrometry, N-terminal sequencing and Western-blot analysis revealed that the crystals contained the C-terminal disulfide-linked cystine-knot dimer. Comparison of various crystallization experiments indicated that degradation of the N-terminal prodomain was dependent on the buffer conditions.

  8. Impact of gut microbiota on the fly's germ line.

    PubMed

    Elgart, Michael; Stern, Shay; Salton, Orit; Gnainsky, Yulia; Heifetz, Yael; Soen, Yoav

    2016-01-01

    Unlike vertically transmitted endosymbionts, which have broad effects on their host's germ line, the extracellular gut microbiota is transmitted horizontally and is not known to influence the germ line. Here we provide evidence supporting the influence of these gut bacteria on the germ line of Drosophila melanogaster. Removal of the gut bacteria represses oogenesis, expedites maternal-to-zygotic-transition in the offspring and unmasks hidden phenotypic variation in mutants. We further show that the main impact on oogenesis is linked to the lack of gut Acetobacter species, and we identify the Drosophila Aldehyde dehydrogenase (Aldh) gene as an apparent mediator of repressed oogenesis in Acetobacter-depleted flies. The finding of interactions between the gut microbiota and the germ line has implications for reproduction, developmental robustness and adaptation. PMID:27080728

  9. Impact of gut microbiota on the fly's germ line

    PubMed Central

    Elgart, Michael; Stern, Shay; Salton, Orit; Gnainsky, Yulia; Heifetz, Yael; Soen, Yoav

    2016-01-01

    Unlike vertically transmitted endosymbionts, which have broad effects on their host's germ line, the extracellular gut microbiota is transmitted horizontally and is not known to influence the germ line. Here we provide evidence supporting the influence of these gut bacteria on the germ line of Drosophila melanogaster. Removal of the gut bacteria represses oogenesis, expedites maternal-to-zygotic-transition in the offspring and unmasks hidden phenotypic variation in mutants. We further show that the main impact on oogenesis is linked to the lack of gut Acetobacter species, and we identify the Drosophila Aldehyde dehydrogenase (Aldh) gene as an apparent mediator of repressed oogenesis in Acetobacter-depleted flies. The finding of interactions between the gut microbiota and the germ line has implications for reproduction, developmental robustness and adaptation. PMID:27080728

  10. Measuring time during early embryonic development.

    PubMed

    Ferree, Patrick L; Deneke, Victoria E; Di Talia, Stefano

    2016-07-01

    In most metazoans, embryonic development is orchestrated by a precise series of cellular behaviors. Understanding how such events are regulated to achieve a stereotypical temporal progression is a fundamental problem in developmental biology. In this review, we argue that studying the regulation of the cell cycle in early embryonic development will reveal novel principles of how embryos accurately measure time. We will discuss the strategies that have emerged from studying early development of Drosophila embryos. By comparing the development of flies to that of other metazoans, we will highlight both conserved and alternative mechanisms to generate precision during embryonic development. PMID:26994526

  11. Initial neurogenesis in Drosophila

    PubMed Central

    Hartenstein, Volker; Wodarz, Andreas

    2014-01-01

    Early neurogenesis comprises the phase of nervous system development during which neural progenitor cells are born. In early development, the embryonic ectoderm is subdivided by a conserved signaling mechanism into two main domains, the epidermal ectoderm and the neurectoderm. Subsequently, cells of the neurectoderm are internalized and form a cell layer of proliferating neural progenitors. In vertebrates, the entire neurectoderm folds into the embryo to give rise to the neural tube. In Drosophila and many other invertebrates, a subset of neurectodermal cells, called neuroblasts (NBs), delaminates and forms the neural primordium inside the embryo where they divide in an asymmetric, stem cell-like mode. The remainder of the neuroectodermal cells that stay behind at the surface loose their neurogenic potential and later give rise to the ventral part of the epidermis. The genetic and molecular analysis of the mechanisms controlling specification and proliferation of NBs in the Drosophila embryo, which played a significant part in pioneering the field of modern developmental neurobiology, represents the topic of this review. PMID:24014455

  12. Initial neurogenesis in Drosophila.

    PubMed

    Hartenstein, Volker; Wodarz, Andreas

    2013-01-01

    Early neurogenesis comprises the phase of nervous system development during which neural progenitor cells are born. In early development, the embryonic ectoderm is subdivided by a conserved signaling mechanism into two main domains, the epidermal ectoderm and the neurectoderm. Subsequently, cells of the neurectoderm are internalized and form a cell layer of proliferating neural progenitors. In vertebrates, the entire neurectoderm folds into the embryo to give rise to the neural tube. In Drosophila and many other invertebrates, a subset of neurectodermal cells, called neuroblasts (NBs), delaminates and forms the neural primordium inside the embryo where they divide in an asymmetric, stem cell-like mode. The remainder of the neurectodermal cells that stay behind at the surface loose their neurogenic potential and later give rise to the ventral part of the epidermis. The genetic and molecular analysis of the mechanisms controlling specification and proliferation of NBs in the Drosophila embryo, which played a significant part in pioneering the field of modern developmental neurobiology, represents the topic of this review. PMID:24014455

  13. Embryonic hematopoiesis.

    PubMed

    Golub, Rachel; Cumano, Ana

    2013-12-01

    Blood cells are continually produced from a pool of progenitors that derive from hematopoietic stem cells (HSCs). In vertebrates, the hematopoietic system develops from two distinct waves or generation of precursors. The first wave occurs in the yolk sac, in mammals or equivalent embryonic structure, and produces nucleated primitive erythrocytes that provide the embryo with the first oxygen transporter and are, therefore, essential for the viability of the embryo. The yolk sac also produces myeloid cells that migrate to the central nervous system and to the skin to form the microglia and skin specific macrophages, the Langerhans cells. The second wave occurs in the dorsal aorta and produces multipotential hematopoietic progenitors. These cells are generated once in the lifetime from mesoderm derivatives closely related to endothelial cells, during a short period of embryonic development. Newly generated cells do not reconstitute the hematopoietic compartment of conventional recipients; therefore, they are designated as immature or pre-HSCs. They undergo maturation into adult HSCs in the aorta or in the fetal liver accompanied by the expression of MHC class I, CD45, CD150, Sca-1 and the absence of CD48. Differentiation of HSCs first occurs in the fetal liver, giving rise to mature blood cells. HSCs also expand in the fetal liver, and in a short time period (four days in the mouse embryo), they increase over 40-fold. HSCs and progenitor cells exit the fetal liver and colonize the spleen, where differentiation to the myeloid lineage and particular lymphoid subsets is favored. PMID:24041595

  14. Conservation of the TGFβ/Labial Homeobox Signaling Loop in Endoderm-Derived Cells between Drosophila and Mammals

    PubMed Central

    Lomberk, Gwen A.; Imoto, Issei; Gebelein, Brian; Urrutia, Raul; Cook, Tiffany A.

    2010-01-01

    Background/Aims Midgut formation in Drosophila melanogaster is dependent upon the integrity of a signaling loop in the endoderm which requires the TGFβ-related peptide, Decapentaplegic, and the Hox transcription factor, Labial. Interestingly, although Labial-like homeobox genes are present in mammals, their participation in endoderm morphogenesis is not clearly understood. Methods We report the cloning, expression, localization, TGFβ inducibility, and biochemical properties of the mammalian Labial-like homeobox, HoxA1, in exocrine pancreatic cells that are embryologically derived from the gut endoderm. Results HoxA1 is expressed in pancreatic cell populations as two alternatively spliced messages, encoding proteins that share their N-terminal domain, but either lack or include the homeobox at the C-terminus. Transcriptional regulatory assays demonstrate that the shared N-terminal domain behaves as a strong transcriptional activator in exocrine pancreatic cells. HoxA1 is an early response gene for TGFβ1 in pancreatic epithelial cell populations and HoxA1 protein co-localizes with TGFβ1 receptors in the embryonic pancreatic epithelium at a time when exocrine pancreatic morphogenesis occurs (days E16 and E17). Conclusions These results report a role for HoxA1 in linking TGFβ-mediated signaling to gene expression in pancreatic epithelial cell populations, thus suggesting a high degree of conservation for a TGFβ/labial signaling loop in endoderm-derived cells between Drosophila and mammals. PMID:20339309

  15. The digestive tract of Drosophila melanogaster.

    PubMed

    Lemaitre, Bruno; Miguel-Aliaga, Irene

    2013-01-01

    The digestive tract plays a central role in the digestion and absorption of nutrients. Far from being a passive tube, it provides the first line of defense against pathogens and maintains energy homeostasis by exchanging neuronal and endocrine signals with other organs. Historically neglected, the gut of the fruit fly Drosophila melanogaster has recently come to the forefront of Drosophila research. Areas as diverse as stem cell biology, neurobiology, metabolism, and immunity are benefitting from the ability to study the genetics of development, growth regulation, and physiology in the same organ. In this review, we summarize our knowledge of the Drosophila digestive tract, with an emphasis on the adult midgut and its functional underpinnings. PMID:24016187

  16. A novel, tissue-specific, Drosophila homeobox gene.

    PubMed Central

    Barad, M; Jack, T; Chadwick, R; McGinnis, W

    1988-01-01

    The homeobox gene family of Drosophila appears to control a variety of position-specific patterning decisions during embryonic and imaginal development. Most of these patterning decisions determine groups of cells on the anterior-posterior axis of the Drosophila germ band. We have isolated a novel homeobox gene from Drosophila, designated H2.0. H2.0 has the most diverged homeobox so far characterized in metazoa, and, in contrast to all previously isolated homeobox genes, H2.0 exhibits a tissue-specific pattern of expression. The cells that accumulate transcripts for this novel gene correspond to the visceral musculature and its anlagen. Images PMID:2901348

  17. Imaging Calcium in Drosophila at Egg Activation.

    PubMed

    Derrick, Christopher J; York-Andersen, Anna H; Weil, Timothy T

    2016-01-01

    Egg activation is a universal process that includes a series of events to allow the fertilized egg to complete meiosis and initiate embryonic development. One aspect of egg activation, conserved across all organisms examined, is a change in the intracellular concentration of calcium (Ca(2+)) often termed a 'Ca(2+) wave'. While the speed and number of oscillations of the Ca(2+) wave varies between species, the change in intracellular Ca(2+) is key in bringing about essential events for embryonic development. These changes include resumption of the cell cycle, mRNA regulation, cortical granule exocytosis, and rearrangement of the cytoskeleton. In the mature Drosophila egg, activation occurs in the female oviduct prior to fertilization, initiating a series of Ca(2+)-dependent events. Here we present a protocol for imaging the Ca(2+) wave in Drosophila. This approach provides a manipulable model system to interrogate the mechanism of the Ca(2+) wave and the downstream changes associated with it. PMID:27584955

  18. Drosophila spermiogenesis

    PubMed Central

    Fabian, Lacramioara; Brill, Julie A.

    2012-01-01

    Drosophila melanogaster spermatids undergo dramatic morphological changes as they differentiate from small round cells approximately 12 μm in diameter into highly polarized, 1.8 mm long, motile sperm capable of participating in fertilization. During spermiogenesis, syncytial cysts of 64 haploid spermatids undergo synchronous differentiation. Numerous changes occur at a subcellular level, including remodeling of existing organelles (mitochondria, nuclei), formation of new organelles (flagellar axonemes, acrosomes), polarization of elongating cysts and plasma membrane addition. At the end of spermatid morphogenesis, organelles, mitochondrial DNA and cytoplasmic components not needed in mature sperm are stripped away in a caspase-dependent process called individualization that results in formation of individual sperm. Here, we review the stages of Drosophila spermiogenesis and examine our current understanding of the cellular and molecular mechanisms involved in shaping male germ cell-specific organelles and forming mature, fertile sperm. PMID:23087837

  19. SUSY GUT Model Building

    SciTech Connect

    Raby, Stuart

    2008-11-23

    In this talk I discuss the evolution of SUSY GUT model building as I see it. Starting with 4 dimensional model building, I then consider orbifold GUTs in 5 dimensions and finally orbifold GUTs embedded into the E{sub 8}xE{sub 8} heterotic string.

  20. The protein 4.1, ezrin, radixin, moesin (FERM) domain of Drosophila Coracle, a cytoplasmic component of the septate junction, provides functions essential for embryonic development and imaginal cell proliferation.

    PubMed Central

    Ward, R E; Schweizer, L; Lamb, R S; Fehon, R G

    2001-01-01

    Coracle is a member of the Protein 4.1 superfamily of proteins, whose members include Protein 4.1, the Neurofibromatosis 2 tumor suppressor Merlin, Expanded, the ERM proteins, protein tyrosine phosphatases, and unconventional myosins. Recent evidence suggests that members of this family participate in cell signaling events, including those that regulate cell proliferation and the cytoskeleton. Previously, we demonstrated that Coracle protein is localized to the septate junction in epithelial cells and is required for septate junction integrity. Loss of coracle function leads to defects in embryonic development, including failure in dorsal closure, and to proliferation defects. In addition, we determined that the N-terminal 383 amino acids define an essential functional domain possessing membrane-organizing properties. Here we investigate the full range of functions provided by this highly conserved domain and find that it is sufficient to rescue all embryonic defects associated with loss of coracle function. In addition, this domain is sufficient to rescue the reduced cell proliferation defect in imaginal discs, although it is incapable of rescuing null mutants to the adult stage. This result suggests the presence of a second functional domain within Coracle, a notion supported by molecular characterization of a series of coracle alleles. PMID:11560899

  1. The protein 4.1, ezrin, radixin, moesin (FERM) domain of Drosophila Coracle, a cytoplasmic component of the septate junction, provides functions essential for embryonic development and imaginal cell proliferation.

    PubMed

    Ward, R E; Schweizer, L; Lamb, R S; Fehon, R G

    2001-09-01

    Coracle is a member of the Protein 4.1 superfamily of proteins, whose members include Protein 4.1, the Neurofibromatosis 2 tumor suppressor Merlin, Expanded, the ERM proteins, protein tyrosine phosphatases, and unconventional myosins. Recent evidence suggests that members of this family participate in cell signaling events, including those that regulate cell proliferation and the cytoskeleton. Previously, we demonstrated that Coracle protein is localized to the septate junction in epithelial cells and is required for septate junction integrity. Loss of coracle function leads to defects in embryonic development, including failure in dorsal closure, and to proliferation defects. In addition, we determined that the N-terminal 383 amino acids define an essential functional domain possessing membrane-organizing properties. Here we investigate the full range of functions provided by this highly conserved domain and find that it is sufficient to rescue all embryonic defects associated with loss of coracle function. In addition, this domain is sufficient to rescue the reduced cell proliferation defect in imaginal discs, although it is incapable of rescuing null mutants to the adult stage. This result suggests the presence of a second functional domain within Coracle, a notion supported by molecular characterization of a series of coracle alleles. PMID:11560899

  2. Drosophila myogenesis.

    PubMed

    Bothe, Ingo; Baylies, Mary K

    2016-09-12

    The skeletal muscle system is the largest organ in motile animals, constituting between 35 and 55% of the human body mass, and up to 75% of the body mass in flying organisms like Drosophila. The flight muscles alone in flying insects comprise up to 65% of total body mass. Not only is the musculature the largest organ system, it is also exquisitely complex, with single muscles existing in different shapes and sizes. These different morphologies allow for such different functions as the high-frequency beating of a wing in a hummingbird, the dilation of the pupil in a human eye, or the maintenance of posture in a giraffe's neck. PMID:27623256

  3. SOX17 links gut endoderm morphogenesis and germ layer segregation.

    PubMed

    Viotti, Manuel; Nowotschin, Sonja; Hadjantonakis, Anna-Katerina

    2014-12-01

    Gastrulation leads to three germ layers--ectoderm, mesoderm and endoderm--that are separated by two basement membranes. In the mouse embryo, the emergent gut endoderm results from the widespread intercalation of cells of two distinct origins: pluripotent epiblast-derived definitive endoderm (DE) and extra-embryonic visceral endoderm (VE). Here we image the trajectory of prospective DE cells before intercalating into the VE epithelium. We show that the transcription factor SOX17, which is activated in prospective DE cells before intercalation, is necessary for gut endoderm morphogenesis and the assembly of the basement membrane that separates gut endoderm from mesoderm. Our results mechanistically link gut endoderm morphogenesis and germ layer segregation, two central and conserved features of gastrulation. PMID:25419850

  4. Invasive and indigenous microbiota impact intestinal stem cell activity through multiple pathways in Drosophila

    PubMed Central

    Buchon, Nicolas; Broderick, Nichole A.; Chakrabarti, Sveta; Lemaitre, Bruno

    2009-01-01

    Gut homeostasis is controlled by both immune and developmental mechanisms, and its disruption can lead to inflammatory disorders or cancerous lesions of the intestine. While the impact of bacteria on the mucosal immune system is beginning to be precisely understood, little is known about the effects of bacteria on gut epithelium renewal. Here, we addressed how both infectious and indigenous bacteria modulate stem cell activity in Drosophila. We show that the increased epithelium renewal observed upon some bacterial infections is a consequence of the oxidative burst, a major defense of the Drosophila gut. Additionally, we provide evidence that the JAK–STAT (Janus kinase–signal transducers and activators of transcription) and JNK (c-Jun NH2 terminal kinase) pathways are both required for bacteria-induced stem cell proliferation. Similarly, we demonstrate that indigenous gut microbiota activate the same, albeit reduced, program at basal levels. Altered control of gut microbiota in immune-deficient or aged flies correlates with increased epithelium renewal. Finally, we show that epithelium renewal is an essential component of Drosophila defense against oral bacterial infection. Altogether, these results indicate that gut homeostasis is achieved by a complex interregulation of the immune response, gut microbiota, and stem cell activity. PMID:19797770

  5. Class I Myosins Have Overlapping and Specialized Functions in Left-Right Asymmetric Development in Drosophila

    PubMed Central

    Okumura, Takashi; Sasamura, Takeshi; Inatomi, Momoko; Hozumi, Shunya; Nakamura, Mitsutoshi; Hatori, Ryo; Taniguchi, Kiichiro; Nakazawa, Naotaka; Suzuki, Emiko; Maeda, Reo; Yamakawa, Tomoko; Matsuno, Kenji

    2015-01-01

    The class I myosin genes are conserved in diverse organisms, and their gene products are involved in actin dynamics, endocytosis, and signal transduction. Drosophila melanogaster has three class I myosin genes, Myosin 31DF (Myo31DF), Myosin 61F (Myo61F), and Myosin 95E (Myo95E). Myo31DF, Myo61F, and Myo95E belong to the Myosin ID, Myosin IC, and Myosin IB families, respectively. Previous loss-of-function analyses of Myo31DF and Myo61F revealed important roles in left–right (LR) asymmetric development and enterocyte maintenance, respectively. However, it was difficult to elucidate their roles in vivo, because of potential redundant activities. Here we generated class I myosin double and triple mutants to address this issue. We found that the triple mutant was viable and fertile, indicating that all three class I myosins were dispensable for survival. A loss-of-function analysis revealed further that Myo31DF and Myo61F, but not Myo95E, had redundant functions in promoting the dextral LR asymmetric development of the male genitalia. Myo61F overexpression is known to antagonize the dextral activity of Myo31DF in various Drosophila organs. Thus, the LR-reversing activity of overexpressed Myo61F may not reflect its physiological function. The endogenous activity of Myo61F in promoting dextral LR asymmetric development was observed in the male genitalia, but not the embryonic gut, another LR asymmetric organ. Thus, Myo61F and Myo31DF, but not Myo95E, play tissue-specific, redundant roles in LR asymmetric development. Our studies also revealed differential colocalization of the class I myosins with filamentous (F)-actin in the brush border of intestinal enterocytes. PMID:25659376

  6. Retinal differentiation in Drosophila.

    PubMed

    Treisman, Jessica E

    2013-07-01

    Drosophila eye development has been extensively studied, due to the ease of genetic screens for mutations disrupting this process. The eye imaginal disc is specified during embryonic and larval development by the Pax6 homolog Eyeless and a network of downstream transcription factors. Expression of these factors is regulated by signaling molecules and also indirectly by growth of the eye disc. Differentiation of photoreceptor clusters initiates in the third larval instar at the posterior of the eye disc and progresses anteriorly, driven by the secreted protein Hedgehog. Within each cluster, the combined activities of Hedgehog signaling and Notch-mediated lateral inhibition induce and refine the expression of the transcription factor Atonal, which specifies the founding R8 photoreceptor of each ommatidium. Seven additional photoreceptors, followed by cone and pigment cells, are successively recruited by the signaling molecules Spitz, Delta, and Bride of sevenless. Combinations of these signals and of intrinsic transcription factors give each ommatidial cell its specific identity. During the pupal stages, rhodopsins are expressed, and the photoreceptors and accessory cells take on their final positions and morphologies to form the adult retina. Over the past few decades, the genetic analysis of this small number of cell types arranged in a repetitive structure has allowed a remarkably detailed understanding of the basic mechanisms controlling cell differentiation and morphological rearrangement. PMID:24014422

  7. Developmental derivation of embryonic and adult macrophages.

    PubMed

    Shepard, J L; Zon, L I

    2000-01-01

    The macrophage cell lineage continually arises from hematopoietic stem cells during embryonic, fetal, and adult life. Previous theories proposed that macrophages are the recent progeny of bone marrow-derived monocytes and that they function primarily in phagocytosis. More recently, however, observations have shown that the ontogeny of macrophages in early mouse and human embryos is different from that occurring during adult development, and that the embryonic macrophages do not follow the monocyte pathway. Fetal macrophages are thought to differentiate from yolk sac-derived primitive macrophages before the development of adult monocytes. Further support for a separate lineage of fetal macrophages has come from studies of several species, including chicken, zebrafish, Xenopus, Drosophila, and C. elegans. The presence of fetal macrophages in PU.1-null mice indicates their independence from monocyte precursors and their existence as an alternative macrophage lineage. PMID:10608497

  8. Oxygen changes drive non-uniform scaling in Drosophila melanogaster embryogenesis

    PubMed Central

    Kuntz, Steven G.; Eisen, Michael B.

    2015-01-01

    We previously demonstrated that, while changes in temperature produce dramatic shifts in the time elapsed during Drosophila melanogaster embryogenesis, the relative timing of events within embryogenesis does not change. However, it was unclear if this uniform scaling is an intrinsic property of developing embryos, or if it is specific to thermal fluctuations. To investigate this, here we characterize the embryonic response to changes in oxygen concentration, which also impact developmental rate, using time-lapse imaging, and find it fundamentally different from the temperature response. Most notably, changes in oxygen levels drive developmental heterochrony, with the timing of several morphological processes showing distinct scaling behaviors. Gut formation is severely slowed by decreases in oxygen, while head involution and syncytial development are less impacted than the rest of development, and the order of several developmental landmarks is inverted at different oxygen levels. These data reveal that the uniform scaling seen with changes in temperature is not a trivial consequence of adjusting developmental rate. The developmental rate changes produced by changing oxygen concentrations dwarf those induced by temperature, and greatly impact survival. While extreme temperatures increase early embryo mortality, mild hypoxia increases arrest and death during mid-embryogenesis and mild hyperoxia increases survival over normoxia. PMID:26673611

  9. Gut microbiota and obesity.

    PubMed

    Gérard, Philippe

    2016-01-01

    The human intestine harbors a complex bacterial community called the gut microbiota. This microbiota is specific to each individual despite the existence of several bacterial species shared by the majority of adults. The influence of the gut microbiota in human health and disease has been revealed in the recent years. Particularly, the use of germ-free animals and microbiota transplant showed that the gut microbiota may play a causal role in the development of obesity and associated metabolic disorders, and lead to identification of several mechanisms. In humans, differences in microbiota composition, functional genes and metabolic activities are observed between obese and lean individuals suggesting a contribution of the gut microbiota to these phenotypes. Finally, the evidence linking gut bacteria to host metabolism could allow the development of new therapeutic strategies based on gut microbiota modulation to treat or prevent obesity. PMID:26459447

  10. The 5S genes of Drosophila melanogaster.

    PubMed

    Artavanis-Tsakonas, S; Schedl, P; Tschudi, C; Pirrotta, V; Steward, R; Gehring, W J

    1977-12-01

    We have cloned embryonic Drosophila DNA using the poly (dA-DT) connector method (Lobban and Kaiser, 1973) and the ampicillin-resistant plasmid pSF2124 (So, Gill and Falkow, 1975) as a cloning vehicle. Two clones, containing hybrid plasmids with sequences complementary to a 5S RNA probe isolated from Drosophila tissue culture cells, were identified by the Grunstein and Hogness (1975) colony hybridization procedure. One hybrid plasmid has a Drosophila insert which is comprised solely of tandem repeats of the 5S gene plus spacer sequences. The other plasmid contains an insert which has about 20 tandem 5S repeat units plus an additional 4 kilobases of adjacent sequences. The size of the 5S repeat unit was determined by gel electrophoresis and was found to be approximately 375 base pairs. We present a restriction map of both plasmids, and a detailed map of of the5S repeat unit. The 5S repat unit shows slight length and sequence heterogeneity. We present evidence suggesting that the 5S genes in Drosophila melanogaster may be arranged in a single continuous cluster. PMID:413625

  11. Frequent Replenishment Sustains the Beneficial Microbiome of Drosophila melanogaster

    PubMed Central

    Blum, Jessamina E.; Fischer, Caleb N.; Miles, Jessica; Handelsman, Jo

    2013-01-01

    ABSTRACT We report that establishment and maintenance of the Drosophila melanogaster microbiome depend on ingestion of bacteria. Frequent transfer of flies to sterile food prevented establishment of the microbiome in newly emerged flies and reduced the predominant members, Acetobacter and Lactobacillus spp., by 10- to 1,000-fold in older flies. Flies with a normal microbiome were less susceptible than germfree flies to infection by Serratia marcescens and Pseudomonas aeruginosa. Augmentation of the normal microbiome with higher populations of Lactobacillus plantarum, a Drosophila commensal and probiotic used in humans, further protected the fly from infection. Replenishment represents an unexplored strategy by which animals can sustain a gut microbial community. Moreover, the population behavior and health benefits of L. plantarum resemble features of certain probiotic bacteria administered to humans. As such, L. plantarum in the fly gut may serve as a simple model for dissecting the population dynamics and mode of action of probiotics in animal hosts. PMID:24194543

  12. Mammalian homologues of the Drosophila eye specification genes.

    PubMed

    Hanson, I M

    2001-12-01

    The Drosophila compound eye is specified by the simultaneous and interdependent activity of transcriptional regulatory genes from four families: PAX6 (eyeless, twin of eyeless, eyegone), EYA (eyes absent), SIX (sine oculis, Optix) and DACH (dachshund). Mammals have homologues of all these genes, and many of them are expressed in the embryonic or adult eye, but the functional relationships between them are currently much less clear than in Drosophila. Nevertheless, mutations in the mammalian genes highlight their requirement both within and outside the eye in embryos and adults, and emphasize that they can be deployed in many different contexts. PMID:11735383

  13. A Drosophila gene encoding a protein resembling the human. beta. -amyloid protein precursor

    SciTech Connect

    Rosen, D.R.; Martin-Morris, L.; Luo, L.; White, K. )

    1989-04-01

    The authors have isolated genomic and cDNA clones for a Drosophila gene resembling the human {beta}-amyloid precursor protein (APP). This gene produces a nervous system-enriched 6.5-kilobase transcript. Sequencing of cDNAs derived from the 6.5-kilobase transcript predicts an 886-amino acid polypeptide. This polypeptide contains a putative transmembrane domain and exhibits strong sequence similarity to cytoplasmic and extracellular regions of the human {beta}-amyloid precursor protein. There is a high probability that this Drosophila gene corresponds to the essential Drosophila locus vnd, a gene required for embryonic nervous system development.

  14. Drosophila PS1 integrin is a laminin receptor and differs in ligand specificity from PS2.

    PubMed Central

    Gotwals, P J; Fessler, L I; Wehrli, M; Hynes, R O

    1994-01-01

    We have expressed Drosophila position-specific (PS) integrins on the surfaces of Schneider S2 cells and tested for adhesion and spreading on various matrix molecules. We report that PS1 integrin is a laminin receptor and that PS1 and PS2 integrins promote cell spreading on two different Drosophila extracellular matrix molecules, laminin and tiggrin, respectively. The differing ligand specificities of these two integrins, combined with data on the in vivo expression patterns of the integrins and their ligands, lead to a model for the structure of integrin-dependent attachments in the pupal wings and embryonic muscles of Drosophila. Images PMID:7972082

  15. Fluorescent visualization of macromolecules in Drosophila whole mounts.

    PubMed

    Ramos, Ricardo Guelerman Pinheiro; Machado, Luciana Claudia Herculano; Moda, Livia Maria Rosatto

    2010-01-01

    The ability to determine the expression dynamics of individual genes "in situ" by visualizing the precise spatial and temporal distribution of their products in whole mounts by histochemical and immunocytochemical reactions has revolutionized our understanding of cellular processes. Drosophila developmental genetics was one of the fields that benefited most from these technologies, and a variety of fluorescent methods were specifically designed for investigating the localization of developmentally important proteins and cell markers during embryonic and post embryonic stages of this model organism. In this chapter we present detailed protocols for fluorescence immunocytochemistry of whole mount embryos, imaginal discs, pupal retinas, and salivary glands of Drosophila melanogaster, as well as methods for fluorescent visualization of specific subcellular structures in these tissues. PMID:20012830

  16. Mechanisms of systemic wound response in Drosophila.

    PubMed

    Lee, Won-Jae; Miura, Masayuki

    2014-01-01

    In response to cellular and tissue losses caused by physical or chemical injuries, organisms must activate multiple wound repair systems at the cellular, tissue, and organismal levels. The systemic wound response (SWR) that occurs via interorgan communication between local wound sites and remote organs ensures that the host is protected efficiently in response to a local wound. The local wound response around the wound site is fairly well documented, but the molecular mechanisms that allow the host to launch SWR are poorly understood. Recent studies on the Drosophila adult model system have shown that the local wound response is not restricted to the wound site because it plays an essential role in generating signals transmitted to remote organs that subsequently achieve SWR. By exploiting the genetic methods available for investigating Drosophila, we are just beginning to understand the complex interorgan networks that operate during SWRs. This review discusses the basic processes involved with classical integumental wound responses and tissue regeneration, such as epithelial cell movement, hemocyte recruitment, apoptosis, melanization, and generation of reactive oxygen species, as well as the recently described intestinal epithelial cell renewal program that occurs in response to gut cell damages. Furthermore, we discuss how these local wound responses integrate with organ-to-organ communication to launch SWR. Genetic analysis of SWRs using the Drosophila model system will provide a unique opportunity to dissect the molecular mechanisms that control wound-induced organ-to-organ communication. PMID:24512709

  17. Hadronic EDMs in SUSY GUTs

    SciTech Connect

    Kakizaki, Mitsuru

    2005-12-02

    We investigate the constraints from the null results of the hadronic electric dipole moment (EDM) searches on supersymmetric grand unified theories (SUSY GUTs). Especially we focus on (i) SUSY SU(5) GUTs with right-handed neutrinos and (ii) orbifold GUTs, where the GUT symmetry and SUSY are both broken by boundary conditions in the compactified extra dimensions. We demonstrate that the hadronic EDM experiments severely constrain SUSY GUT models. The interplay between future EDM and LFV experiments will probe the structures of the GUTs and the SUSY breaking mediation mechanism.

  18. Healthy human gut phageome.

    PubMed

    Manrique, Pilar; Bolduc, Benjamin; Walk, Seth T; van der Oost, John; de Vos, Willem M; Young, Mark J

    2016-09-13

    The role of bacteriophages in influencing the structure and function of the healthy human gut microbiome is unknown. With few exceptions, previous studies have found a high level of heterogeneity in bacteriophages from healthy individuals. To better estimate and identify the shared phageome of humans, we analyzed a deep DNA sequence dataset of active bacteriophages and available metagenomic datasets of the gut bacteriophage community from healthy individuals. We found 23 shared bacteriophages in more than one-half of 64 healthy individuals from around the world. These shared bacteriophages were found in a significantly smaller percentage of individuals with gastrointestinal/irritable bowel disease. A network analysis identified 44 bacteriophage groups of which 9 (20%) were shared in more than one-half of all 64 individuals. These results provide strong evidence of a healthy gut phageome (HGP) in humans. The bacteriophage community in the human gut is a mixture of three classes: a set of core bacteriophages shared among more than one-half of all people, a common set of bacteriophages found in 20-50% of individuals, and a set of bacteriophages that are either rarely shared or unique to a person. We propose that the core and common bacteriophage communities are globally distributed and comprise the HGP, which plays an important role in maintaining gut microbiome structure/function and thereby contributes significantly to human health. PMID:27573828

  19. Gut feeling is electric

    NASA Astrophysics Data System (ADS)

    Familoni, Jide

    2011-06-01

    Although "gut feeling" is a cliché in English parlance, there are neuro-physiological basis for registration of emotions in the gut. Control of the gastro-intestinal (GI) tract is by an integration of neuro-hormonal factors from the local myogenic to the central nervous system. Gastric contractile activity, which is responsible for the motor properties of the stomach, is regulated by this integrated complex. Signatures of the activity include gastric electrical activity (GEA) and bowel sounds. GEA has two distinct components: a high-frequency spike activity or post depolarization potential termed the electrical response activity superimposed on a lower frequency, rhythmic depolarization termed the control activity. These signatures are measured in the clinic with contact sensors and well understood for diagnosis of gut dysmotility. Can these signatures be measured at standoff and employed for purposes of biometrics, malintent and wellness assessment?

  20. Gut stem cells, a story of snails, flies and mice

    PubMed Central

    Amoyel, Marc

    2015-01-01

    Intestinal stem cells (ISCs) replenish and regenerate several types of cells in the gut, both during normal homeostasis and in response to various insults such as infections. Although gut structure and complexity vary across phyla, two functional categories of differentiated cell types are always present: absorptive cells and those of the secretory lineage. A series of studies in Drosophila and mouse published in The EMBO Journal, including one in this issue, identifies conserved roles for the Snail family of zinc finger transcription factors in regulating self-renewal and differentiation of ISCs (Korzelius et al, 2014; Loza-Coll et al, 2014; Horvay et al, 2015). PMID:25863942

  1. Embryonic development of the cricket Gryllus bimaculatus.

    PubMed

    Donoughe, Seth; Extavour, Cassandra G

    2016-03-01

    Extensive research into Drosophila melanogaster embryogenesis has improved our understanding of insect developmental mechanisms. However, Drosophila development is thought to be highly divergent from that of the ancestral insect and arthropod in many respects. We therefore need alternative models for arthopod development that are likely to be more representative of basally-branching clades. The cricket Gryllus bimaculatus is such a model, and currently has the most sophisticated functional genetic toolkit of any hemimetabolous insect. The existing cricket embryonic staging system is fragmentary, and it is based on morphological landmarks that are not easily visible on a live, undissected egg. To address this problem, here we present a complementary set of "egg stages" that serve as a guide for identifying the developmental progress of a cricket embryo from fertilization to hatching, based solely on the external appearance of the egg. These stages were characterized using a combination of brightfield timelapse microscopy, timed brightfield micrographs, confocal microscopy, and measurements of egg dimensions. These egg stages are particularly useful in experiments that involve egg injection (including RNA interference, targeted genome modification, and transgenesis), as injection can alter the speed of development, even in control treatments. We also use 3D reconstructions of fixed embryo preparations to provide a comprehensive description of the morphogenesis and anatomy of the cricket embryo during embryonic rudiment assembly, germ band formation, elongation, segmentation, and appendage formation. Finally, we aggregate and schematize a variety of published developmental gene expression patterns. This work will facilitate further studies on G. bimaculatus development, and serve as a useful point of reference for other studies of wild type and experimentally manipulated insect development in fields from evo-devo to disease vector and pest management. PMID:25907229

  2. Gut chemosensing mechanisms

    PubMed Central

    Psichas, Arianna; Reimann, Frank; Gribble, Fiona M.

    2015-01-01

    The enteroendocrine system is the primary sensor of ingested nutrients and is responsible for secreting an array of gut hormones, which modulate multiple physiological responses including gastrointestinal motility and secretion, glucose homeostasis, and appetite. This Review provides an up-to-date synopsis of the molecular mechanisms underlying enteroendocrine nutrient sensing and highlights our current understanding of the neuro-hormonal regulation of gut hormone secretion, including the interaction between the enteroendocrine system and the enteric nervous system. It is hoped that a deeper understanding of how these systems collectively regulate postprandial physiology will further facilitate the development of novel therapeutic strategies. PMID:25664852

  3. Ferritin Is Required in Multiple Tissues during Drosophila melanogaster Development

    PubMed Central

    Blowes, Liisa M.; Missirlis, Fanis; Riesgo-Escovar, Juan R.

    2015-01-01

    In Drosophila melanogaster, iron is stored in the cellular endomembrane system inside a protein cage formed by 24 ferritin subunits of two types (Fer1HCH and Fer2LCH) in a 1:1 stoichiometry. In larvae, ferritin accumulates in the midgut, hemolymph, garland, pericardial cells and in the nervous system. Here we present analyses of embryonic phenotypes for mutations in Fer1HCH, Fer2LCH and in both genes simultaneously. Mutations in either gene or deletion of both genes results in a similar set of cuticular embryonic phenotypes, ranging from non-deposition of cuticle to defects associated with germ band retraction, dorsal closure and head involution. A fraction of ferritin mutants have embryonic nervous systems with ventral nerve cord disruptions, misguided axonal projections and brain malformations. Ferritin mutants die with ectopic apoptotic events. Furthermore, we show that ferritin maternal contribution, which varies reflecting the mother’s iron stores, is used in early development. We also evaluated phenotypes arising from the blockage of COPII transport from the endoplasmic reticulum to the Golgi apparatus, feeding the secretory pathway, plus analysis of ectopically expressed and fluorescently marked Fer1HCH and Fer2LCH. Overall, our results are consistent with insect ferritin combining three functions: iron storage, intercellular iron transport, and protection from iron-induced oxidative stress. These functions are required in multiple tissues during Drosophila embryonic development. PMID:26192321

  4. Molecular mechanism and functional significance of acid generation in the Drosophila midgut

    PubMed Central

    Overend, Gayle; Luo, Yuan; Henderson, Louise; Douglas, Angela E.; Davies, Shireen A.; Dow, Julian A. T.

    2016-01-01

    The gut of Drosophila melanogaster includes a proximal acidic region (~pH 2), however the genome lacks the H+/K+ ATPase characteristic of the mammalian gastric parietal cell, and the molecular mechanisms of acid generation are poorly understood. Here, we show that maintenance of the low pH of the acidic region is dependent on H+ V-ATPase, together with carbonic anhydrase and five further transporters or channels that mediate K+, Cl− and HCO3− transport. Abrogation of the low pH did not influence larval survival under standard laboratory conditions, but was deleterious for insects subjected to high Na+ or K+ load. Insects with elevated pH in the acidic region displayed increased susceptibility to Pseudomonas pathogens and increased abundance of key members of the gut microbiota (Acetobacter and Lactobacillus), suggesting that the acidic region has bacteriostatic or bacteriocidal activity. Conversely, the pH of the acidic region was significantly reduced in germ-free Drosophila, indicative of a role of the gut bacteria in shaping the pH conditions of the gut. These results demonstrate that the acidic gut region protects the insect and gut microbiome from pathological disruption, and shed light on the mechanisms by which low pH can be maintained in the absence of H+, K+ ATPase. PMID:27250760

  5. Molecular mechanism and functional significance of acid generation in the Drosophila midgut.

    PubMed

    Overend, Gayle; Luo, Yuan; Henderson, Louise; Douglas, Angela E; Davies, Shireen A; Dow, Julian A T

    2016-01-01

    The gut of Drosophila melanogaster includes a proximal acidic region (~pH 2), however the genome lacks the H(+)/K(+) ATPase characteristic of the mammalian gastric parietal cell, and the molecular mechanisms of acid generation are poorly understood. Here, we show that maintenance of the low pH of the acidic region is dependent on H(+) V-ATPase, together with carbonic anhydrase and five further transporters or channels that mediate K(+), Cl(-) and HCO3(-) transport. Abrogation of the low pH did not influence larval survival under standard laboratory conditions, but was deleterious for insects subjected to high Na(+) or K(+) load. Insects with elevated pH in the acidic region displayed increased susceptibility to Pseudomonas pathogens and increased abundance of key members of the gut microbiota (Acetobacter and Lactobacillus), suggesting that the acidic region has bacteriostatic or bacteriocidal activity. Conversely, the pH of the acidic region was significantly reduced in germ-free Drosophila, indicative of a role of the gut bacteria in shaping the pH conditions of the gut. These results demonstrate that the acidic gut region protects the insect and gut microbiome from pathological disruption, and shed light on the mechanisms by which low pH can be maintained in the absence of H(+), K(+) ATPase. PMID:27250760

  6. Philosophy with Guts

    ERIC Educational Resources Information Center

    Sherman, Robert R.

    2014-01-01

    Western philosophy, from Plato on, has had the tendency to separate feeling and thought, affect and cognition. This article argues that a strong philosophy (metaphorically, with "guts") utilizes both in its work. In fact, a "complete act of thought" also will include action. Feeling motivates thought, which formulates ideas,…

  7. The Human Gut Microbiota.

    PubMed

    Harmsen, Hermie J M; de Goffau, Marcus C

    2016-01-01

    The microbiota in our gut performs many different essential functions that help us to stay healthy. These functions include vitamin production, regulation of lipid metabolism and short chain fatty acid production as fuel for epithelial cells and regulation of gene expression. There is a very numerous and diverse microbial community present in the gut, especially in the colon, with reported numbers of species that vary between 400 and 1500, for some those we even do not yet have culture representatives.A healthy gut microbiota is important for maintaining a healthy host. An aberrant microbiota can cause diseases of different nature and at different ages ranging from allergies at early age to IBD in young adults. This shows that our gut microbiota needs to be treated well to stay healthy. In this chapter we describe what we consider a healthy microbiota and discuss what the role of the microbiota is in various diseases. Research into these described dysbiosis conditions could lead to new strategies for treatment and/or management of our microbiota to improve health. PMID:27161353

  8. The Drosophila visual system

    PubMed Central

    Zhu, Yan

    2013-01-01

    A compact genome and a tiny brain make Drosophila the prime model to understand the neural substrate of behavior. The neurogenetic efforts to reveal neural circuits underlying Drosophila vision started about half a century ago, and now the field is booming with sophisticated genetic tools, rich behavioral assays, and importantly, a greater number of scientists joining from different backgrounds. This review will briefly cover the structural anatomy of the Drosophila visual system, the animal’s visual behaviors, the genes involved in assembling these circuits, the new and powerful techniques, and the challenges ahead for ultimately identifying the general principles of biological computation in the brain.   A typical brain utilizes a great many compact neural circuits to collect and process information from the internal biological and external environmental worlds and generates motor commands for observable behaviors. The fruit fly Drosophila melanogaster, despite of its miniature body and tiny brain, can survive in almost any corner of the world.1 It can find food, court mate, fight rival conspecific, avoid predators, and amazingly fly without crashing into trees. Drosophila vision and its underlying neuronal machinery has been a key research model for at least half century for neurogeneticists.2 Given the efforts invested on the visual system, this animal model is likely to offer the first full understanding of how visual information is computed by a multi-cellular organism. Furthermore, research in Drosophila has revealed many genes that play crucial roles in the formation of functional brains across species. The architectural similarities between the visual systems of Drosophila and vertebrate at the molecular, cellular, and network levels suggest new principles discovered at the circuit level on the relationship between neurons and behavior in Drosophila shall also contribute greatly to our understanding of the general principles for how bigger brains work.3

  9. Drosophila Blastorderm Analysis Software

    SciTech Connect

    2006-10-25

    PointCloudMake analyzes 3D fluorescent images of whole Drosophila embryo and produces a table-style "PointCloud" file which contains the coordinates and volumes of all the nuclei, cells, their associated relative gene expression levels along with morphological features of the embryo. See: Luengo Hendrix et at 2006 3D Morphology and Gene Expression in the Drosophila Blastoderm at Cellular Resolution manuscript submitted LBNL # LBNL-60178 Knowles DW, Keranen SVE, Biggin M. Sudar S (2002) Mapping organism expression levels at cellular resolution in developing Drosophila. In: Conchello JA, Cogswell CJ, Wilson T, editors. Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing IX. pp. 57-64

  10. Maternal control of the Drosophila dorsal–ventral body axis

    PubMed Central

    Stein, David S.; Stevens, Leslie M.

    2016-01-01

    The pathway that generates the dorsal–ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity. PMID:25124754

  11. Meiosis in male Drosophila

    PubMed Central

    McKee, Bruce D.; Yan, Rihui; Tsai, Jui-He

    2012-01-01

    Meiosis entails sorting and separating both homologous and sister chromatids. The mechanisms for connecting sister chromatids and homologs during meiosis are highly conserved and include specialized forms of the cohesin complex and a tightly regulated homolog synapsis/recombination pathway designed to yield regular crossovers between homologous chromatids. Drosophila male meiosis is of special interest because it dispenses with large segments of the standard meiotic script, particularly recombination, synapsis and the associated structures. Instead, Drosophila relies on a unique protein complex composed of at least two novel proteins, SNM and MNM, to provide stable connections between homologs during meiosis I. Sister chromatid cohesion in Drosophila is mediated by cohesins, ring-shaped complexes that entrap sister chromatids. However, unlike other eukaryotes Drosophila does not rely on the highly conserved Rec8 cohesin in meiosis, but instead utilizes two novel cohesion proteins, ORD and SOLO, which interact with the SMC1/3 cohesin components in providing meiotic cohesion. PMID:23087836

  12. In focus: spotted wing drosophila, Drosophila suzukii, across perspectives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An effective response to the invasion of spotted wing Drosophila (SWD), Drosophila suzukii, requires proper taxonomic identification at the initial phase, understanding its basic biology and phenology, developing management tools, transferring information and technology quickly to user groups, and e...

  13. Obesity and the gut microbiota.

    PubMed

    Flint, Harry J

    2011-11-01

    Gut microorganisms have the potential to influence weight gain and fat deposition through a variety of mechanisms. One factor is the ability of microorganisms in the large intestine to release energy by fermenting otherwise indigestible components of the diet ("energy harvest"). This energy becomes available to the host indirectly through the absorption of microbially produced short-chain fatty acids. Energy recovery from fiber will be largely determined by dietary intake and gut transit, but can also depend on the makeup of the gut microbiota. The species composition of the gut microbiota changes with diet composition, as has been shown in studies with obese individuals after reduced carbohydrate weight loss diets, or diets containing different nondigestible carbohydrates. There is conflicting evidence, however, on the extent to which gut microbiota composition differs between obese and nonobese humans. In contrast, there is increasing evidence to suggest that gut microorganisms and their metabolic products can influence gut hormones, inflammation, and gut motility. Any changes in gut microbiota composition that influence energy expenditure, satiety, and food intake have the potential to alter weight gain and weight loss, but a better understanding of the impact of different members of the gut microbial community upon host physiology is needed to establish these relationships. PMID:21992951

  14. Endocannabinoids in the Gut

    PubMed Central

    DiPatrizio, Nicholas V.

    2016-01-01

    Cannabis has been used medicinally for centuries to treat a variety of disorders, including those associated with the gastrointestinal tract. The discovery of our bodies’ own “cannabis-like molecules” and associated receptors and metabolic machinery – collectively called the endocannabinoid system – enabled investigations into the physiological relevance for the system, and provided the field with evidence of a critical function for this endogenous signaling pathway in health and disease. Recent investigations yield insight into a significant participation for the endocannabinoid system in the normal physiology of gastrointestinal function, and its possible dysfunction in gastrointestinal pathology. Many gaps, however, remain in our understanding of the precise neural and molecular mechanisms across tissue departments that are under the regulatory control of the endocannabinoid system. This review highlights research that reveals an important – and at times surprising – role for the endocannabinoid system in the control of a variety of gastrointestinal functions, including motility, gut-brain mediated fat intake and hunger signaling, inflammation and gut permeability, and dynamic interactions with gut microbiota. PMID:27413788

  15. Gut microbiota and liver diseases

    PubMed Central

    Minemura, Masami; Shimizu, Yukihiro

    2015-01-01

    Several studies revealed that gut microbiota are associated with various human diseases, e.g., metabolic diseases, allergies, gastroenterological diseases, and liver diseases. The liver can be greatly affected by changes in gut microbiota due to the entry of gut bacteria or their metabolites into the liver through the portal vein, and the liver-gut axis is important to understand the pathophysiology of several liver diseases, especially non-alcoholic fatty liver disease and hepatic encephalopathy. Moreover, gut microbiota play a significant role in the development of alcoholic liver disease and hepatocarcinogenesis. Based on these previous findings, trials using probiotics have been performed for the prevention or treatment of liver diseases. In this review, we summarize the current understanding of the changes in gut microbiota associated with various liver diseases, and we describe the therapeutic trials of probiotics for those diseases. PMID:25684933

  16. Gut Microbiota and Metabolic Disorders.

    PubMed

    Hur, Kyu Yeon; Lee, Myung-Shik

    2015-06-01

    Gut microbiota plays critical physiological roles in the energy extraction and in the control of local or systemic immunity. Gut microbiota and its disturbance also appear to be involved in the pathogenesis of diverse diseases including metabolic disorders, gastrointestinal diseases, cancer, etc. In the metabolic point of view, gut microbiota can modulate lipid accumulation, lipopolysaccharide content and the production of short-chain fatty acids that affect food intake, inflammatory tone, or insulin signaling. Several strategies have been developed to change gut microbiota such as prebiotics, probiotics, certain antidiabetic drugs or fecal microbiota transplantation, which have diverse effects on body metabolism and on the development of metabolic disorders. PMID:26124989

  17. Localization and possible functions of Drosophila septins.

    PubMed Central

    Fares, H; Peifer, M; Pringle, J R

    1995-01-01

    The septins are a family of homologous proteins that were originally identified in Saccharomyces cerevisiae, where they are associated with the "neck filaments" and are involved in cytokinesis and other aspects of the organization of the cell surface. We report here the identification of Sep1, a Drosophila melanogaster septin, based on its homology to the yeast septins. The predicted Sep1 amino acid sequence is 35-42% identical to the known S. cerevisiae septins; 52% identical to Pnut, a second D. melanogaster septin; and 53-73% identical to the known mammalian septins. Sep1-specific antibodies have been used to characterize its expression and localization. The protein is concentrated at the leading edge of the cleavage furrows of dividing cells and cellularizing embryos, suggesting a role in furrow formation. Other aspects of Sep1 localization suggest roles not directly related to cytokinesis. For example, Sep1 exhibits orderly, cell-cycle-coordinated rearrangements within the cortex of syncytial blastoderm embryos and in the cells of post-gastrulation embryos; Sep1 is also concentrated at the leading edge of the epithelium during dorsal closure in the embryo, in the neurons of the embryonic nervous system, and at the baso-lateral surfaces of ovarian follicle cells. The distribution of Sep1 typically overlaps, but is distinct from, that of actin. Both immunolocalization and biochemical experiments show that Sep1 is intimately associated with Pnut, suggesting that the Drosophila septins, like those in yeast, function as part of a complex. Images PMID:8590810

  18. Gravity and embryonic development

    NASA Technical Reports Server (NTRS)

    Young, R. S.

    1976-01-01

    The relationship between the developing embryo (both plant and animal) and a gravitational field has long been contemplated. The difficulty in designing critical experiments on the surface of the earth because of its background of 1 g, has been an obstacle to a resolution of the problem. Biological responses to gravity (particularly in plants) are obvious in many cases; however, the influence of gravity as an environmental input to the developing embryo is not as obvious and has proven to be extremely difficult to define. In spite of this, over the years numerous attempts have been made using a variety of embryonic materials to come to grips with the role of gravity in development. Three research tools are available: the centrifuge, the clinostat, and the orbiting spacecraft. Experimental results are now available from all three sources. Some tenuous conclusions are drawn, and an attempt at a unifying theory of gravitational influence on embryonic development is made.

  19. Calmodulin Point Mutations Affect Drosophila Development and Behavior

    PubMed Central

    Nelson, H. B.; Heiman, R. G.; Bolduc, C.; Kovalick, G. E.; Whitley, P.; Stern, M.; Beckingham, K.

    1997-01-01

    Calmodulin (CAM) is recognized as a major intermediary in intracellular calcium signaling, but as yet little is known of its role in developmental and behavioral processes. We have generated and studied mutations to the endogenous Cam gene of Drosophila melanogaster that change single amino acids within the protein coding region. One of these mutations produces a striking pupal lethal phenotype involving failure of head eversion. Various mutant combinations produce specific patterns of ectopic wing vein formation or melanotic scabs on the cuticle. Anaphase chromosome bridging is also seen as a maternal effect during the early embryonic nuclear divisions. In addition, specific behavioral defects such as poor climbing and flightlessness are detected among these mutants. Comparisons with other Drosophila mutant phenotypes suggests potential CAM targets that may mediate these developmental and behavioral effects, and analysis of the CAM crystal structure suggests the structural consequences of the individual mutations. PMID:9409836

  20. Drosophila Blastorderm Analysis Software

    Energy Science and Technology Software Center (ESTSC)

    2006-10-25

    PointCloudMake analyzes 3D fluorescent images of whole Drosophila embryo and produces a table-style "PointCloud" file which contains the coordinates and volumes of all the nuclei, cells, their associated relative gene expression levels along with morphological features of the embryo. See: Luengo Hendrix et at 2006 3D Morphology and Gene Expression in the Drosophila Blastoderm at Cellular Resolution manuscript submitted LBNL # LBNL-60178 Knowles DW, Keranen SVE, Biggin M. Sudar S (2002) Mapping organism expression levelsmore » at cellular resolution in developing Drosophila. In: Conchello JA, Cogswell CJ, Wilson T, editors. Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing IX. pp. 57-64« less

  1. GUTs and TOEs

    SciTech Connect

    Lincoln, Don

    2015-01-20

    Albert Einstein said that what he wanted to know was “God’s thoughts,” which is a metaphor for the ultimate and most basic rules of the universe. Once known, all other phenomena would then be a consequence of these simple rules. While modern science is far from that goal, we have some thoughts on how this inquiry might unfold. In this video, Fermilab’s Dr. Don Lincoln tells what we know about GUTs (grand unified theories) and TOEs (theories of everything).

  2. Visualization of clathrin-mediated endocytosis in live Drosophila egg chambers

    PubMed Central

    Jha, Anupma; Traub, Linton M.

    2015-01-01

    Summary In oviparous animals, clathrin-dependent endocytosis is often critical to stockpile a necessary supply of yolk within the maturing oocyte, which enables subsequent embryonic development. In the physically linked chains of maturing egg chambers within the Drosophila melanogaster ovary, a distinct, morphologically discernable, subset undergoes a massive burst clathrin-mediated endocytosis to accumulate yolk in a process termed vitellogenesis. Here, we describe how to prepare isolated ovaries to follow endocytosis, and detail approaches to follow live uptake of soluble reporters into vitellogenic Drosophila egg chambers. PMID:24947394

  3. The giant panda gut microbiome.

    PubMed

    Wei, Fuwen; Wang, Xiao; Wu, Qi

    2015-08-01

    Giant pandas (Ailuropoda melanoleuca) are bamboo specialists that evolved from carnivores. Their gut microbiota probably aids in the digestion of cellulose and this is considered an example of gut microbiota adaptation to a bamboo diet. However, this issue remains unresolved and further functional and compositional studies are needed. PMID:26143242

  4. Metagenomic surveys of gut microbiota.

    PubMed

    Mandal, Rahul Shubhra; Saha, Sudipto; Das, Santasabuj

    2015-06-01

    Gut microbiota of higher vertebrates is host-specific. The number and diversity of the organisms residing within the gut ecosystem are defined by physiological and environmental factors, such as host genotype, habitat, and diet. Recently, culture-independent sequencing techniques have added a new dimension to the study of gut microbiota and the challenge to analyze the large volume of sequencing data is increasingly addressed by the development of novel computational tools and methods. Interestingly, gut microbiota maintains a constant relative abundance at operational taxonomic unit (OTU) levels and altered bacterial abundance has been associated with complex diseases such as symptomatic atherosclerosis, type 2 diabetes, obesity, and colorectal cancer. Therefore, the study of gut microbial population has emerged as an important field of research in order to ultimately achieve better health. In addition, there is a spontaneous, non-linear, and dynamic interaction among different bacterial species residing in the gut. Thus, predicting the influence of perturbed microbe-microbe interaction network on health can aid in developing novel therapeutics. Here, we summarize the population abundance of gut microbiota and its variation in different clinical states, computational tools available to analyze the pyrosequencing data, and gut microbe-microbe interaction networks. PMID:26184859

  5. Metagenomic Surveys of Gut Microbiota

    PubMed Central

    Mandal, Rahul Shubhra; Saha, Sudipto; Das, Santasabuj

    2015-01-01

    Gut microbiota of higher vertebrates is host-specific. The number and diversity of the organisms residing within the gut ecosystem are defined by physiological and environmental factors, such as host genotype, habitat, and diet. Recently, culture-independent sequencing techniques have added a new dimension to the study of gut microbiota and the challenge to analyze the large volume of sequencing data is increasingly addressed by the development of novel computational tools and methods. Interestingly, gut microbiota maintains a constant relative abundance at operational taxonomic unit (OTU) levels and altered bacterial abundance has been associated with complex diseases such as symptomatic atherosclerosis, type 2 diabetes, obesity, and colorectal cancer. Therefore, the study of gut microbial population has emerged as an important field of research in order to ultimately achieve better health. In addition, there is a spontaneous, non-linear, and dynamic interaction among different bacterial species residing in the gut. Thus, predicting the influence of perturbed microbe–microbe interaction network on health can aid in developing novel therapeutics. Here, we summarize the population abundance of gut microbiota and its variation in different clinical states, computational tools available to analyze the pyrosequencing data, and gut microbe–microbe interaction networks. PMID:26184859

  6. Gut Microbiota: The Brain Peacekeeper.

    PubMed

    Mu, Chunlong; Yang, Yuxiang; Zhu, Weiyun

    2016-01-01

    Gut microbiota regulates intestinal and extraintestinal homeostasis. Accumulating evidence suggests that the gut microbiota may also regulate brain function and behavior. Results from animal models indicate that disturbances in the composition and functionality of some microbiota members are associated with neurophysiological disorders, strengthening the idea of a microbiota-gut-brain axis and the role of microbiota as a "peacekeeper" in the brain health. Here, we review recent discoveries on the role of the gut microbiota in central nervous system-related diseases. We also discuss the emerging concept of the bidirectional regulation by the circadian rhythm and gut microbiota, and the potential role of the epigenetic regulation in neuronal cell function. Microbiome studies are also highlighted as crucial in the development of targeted therapies for neurodevelopmental disorders. PMID:27014255

  7. Collective synchronization of divisions in Drosophila development

    NASA Astrophysics Data System (ADS)

    Vergassola, Massimo

    Mitoses in the early development of most metazoans are rapid and synchronized across the entire embryo. While diffusion is too slow, in vitro experiments have shown that waves of the cell-cycle regulator Cdk1 can transfer information rapidly across hundreds of microns. However, the signaling dynamics and the physical properties of chemical waves during embryonic development remain unclear. We develop FRET biosensors for the activity of Cdk1 and the checkpoint kinase Chk1 in Drosophila embryos and exploit them to measure waves in vivo. We demonstrate that Cdk1 chemical waves control mitotic waves and that their speed is regulated by the activity of Cdk1 during the S-phase (and not mitosis). We quantify the progressive slowdown of the waves with developmental cycles and identify its underlying control mechanism by the DNA replication checkpoint through the Chk1/Wee1 pathway. The global dynamics of the mitotic signaling network illustrates a novel control principle: the S-phase activity of Cdk1 regulates the speed of the mitotic wave, while the Cdk1 positive feedback ensures an invariantly rapid onset of mitosis. Mathematical modeling captures the speed of the waves and predicts a fundamental distinction between the S-phase Cdk1 trigger waves and the mitotic phase waves, which is illustrated by embryonic ablation experiments. In collaboration with Victoria Deneke1, Anna Melbinger2, and Stefano Di Talia1 1 Department of Cell Biology, Duke University Medical Center 2 Department of Physics, University of California San Diego.

  8. mRNA Localization and Translational Control in Drosophila Oogenesis

    PubMed Central

    Lasko, Paul

    2012-01-01

    Localization of an mRNA species to a particular subcellular region can complement translational control mechanisms to produce a restricted spatial distribution of the protein it encodes. mRNA localization has been studied most in asymmetric cells such as budding yeast, early embryos, and neurons, but the process is likely to be more widespread. This article reviews the current state of knowledge about the mechanisms of mRNA localization and its functions in early embryonic development, focusing on Drosophila where the relevant knowledge is most advanced. Links between mRNA localization and translational control mechanisms also are examined. PMID:22865893

  9. Isolation of Enteric Nervous System Progenitor Cells from the Aganglionic Gut of Patients with Hirschsprung’s Disease

    PubMed Central

    Wilkinson, David J.; Bethell, George S.; Shukla, Rajeev; Kenny, Simon E.; Edgar, David H.

    2015-01-01

    Enteric nervous system progenitor cells isolated from postnatal human gut and cultured as neurospheres can then be transplanted into aganglionic gut to restore normal patterns of contractility. These progenitor cells may be of future use to treat patients with Hirschprung’s disease, a congenital condition characterized by hindgut dysmotility due to the lack of enteric nervous system ganglia. Here we demonstrate that progenitor cells can also be isolated from aganglionic gut removed during corrective surgery for Hirschsprung’s disease. Although the enteric nervous system marker calretinin is not expressed in the aganglionic gut region, de novo expression is initiated in cultured neurosphere cells isolated from aganglionic Hirschsprung bowel. Furthermore, expression of the neural markers NOS, VIP and GFAP also increased during culture of aganglionic gut neurospheres which we show can be transplantation into cultured embryonic mouse gut explants to restore a normal frequency of contractility. To determine the origin of the progenitor cells in aganglionic region, we used fluorescence-activated cell sorting to demonstrate that only p75-positive neural crest-derived cells present in the thickened nerve trunks characteristic of the aganglionic region of Hirschsprung gut gave rise to neurons in culture. The derivation of enteric nervous system progenitors in the aganglionic gut region of Hirschprung’s patients not only means that this tissue is a potential source of cells for future autologous transplantation, but it also raises the possibility of inducing the differentiation of these endogenous cells in situ to compensate for the aganglionosis. PMID:25992739

  10. NPAS1 regulates branching morphogenesis in embryonic lung.

    PubMed

    Levesque, Bernadette M; Zhou, Shutang; Shan, Lin; Johnston, Pamela; Kong, Yanping; Degan, Simone; Sunday, Mary E

    2007-04-01

    Drosophila trachealess (Trl), master regulator of tracheogenesis, has no known functional mammalian homolog. We hypothesized that genes similar to trachealess regulate lung development. Quantitative (Q)RT-PCR and immunostaining were used to determine spatial and temporal patterns of npas1 gene expression in developing murine lung. Immunostaining for alpha-smooth muscle actin demonstrated myofibroblasts, and protein gene product (PGP)9.5 identified neuroendocrine cells. Branching morphogenesis of embryonic lung buds was analyzed in the presence of antisense or sense oligodeoxynucleotides (ODN). Microarray analyses were performed to screen for changes in gene expression in antisense-treated lungs. QRT-PCR was used to validate the altered expression of key genes identified on the microarrays. We demonstrate that npas1 is expressed in murine embryonic lung. npas1 mRNA peaks early at Embryonic Day (E)10.5-E11.5, then drops to low levels. Sequencing verifies the identity of npas1 transcripts in embryonic lung. NPAS1 immunostaining occurs in nuclei of parabronchial mesenchymal cells, especially at the tracheal bifurcation. Arnt, the murine homolog of Tango (the heterodimerization partner for Trl) is also expressed in developing lung but at constant levels. npas1- or arnt-antisense ODN inhibit lung branching morphogenesis, with altered myofibroblast development and increased pulmonary neuroendocrine cells. On microarrays, we identify > 50 known genes down-regulated by npas1-antisense, including multiple genes regulating cell migration and cell differentiation. QRT-PCR confirms significantly decreased expression of the neurogenic genes RBP-Jk and Tle, and three genes involved in muscle development: beta-ig-h3, claudin-11, and myocardin. Npas1 can regulate myofibroblast distribution, branching morphogenesis, and neuroendocrine cell differentiation in murine embryonic lung. PMID:17110583

  11. Heritable Endosymbionts of Drosophila

    PubMed Central

    Mateos, Mariana; Castrezana, Sergio J.; Nankivell, Becky J.; Estes, Anne M.; Markow, Therese A.; Moran, Nancy A.

    2006-01-01

    Although heritable microorganisms are increasingly recognized as widespread in insects, no systematic screens for such symbionts have been conducted in Drosophila species (the primary insect genetic models for studies of evolution, development, and innate immunity). Previous efforts screened relatively few Drosophila lineages, mainly for Wolbachia. We conducted an extensive survey of potentially heritable endosymbionts from any bacterial lineage via PCR screens of mature ovaries in 181 recently collected fly strains representing 35 species from 11 species groups. Due to our fly sampling methods, however, we are likely to have missed fly strains infected with sex ratio-distorting endosymbionts. Only Wolbachia and Spiroplasma, both widespread in insects, were confirmed as symbionts. These findings indicate that in contrast to some other insect groups, other heritable symbionts are uncommon in Drosophila species, possibly reflecting a robust innate immune response that eliminates many bacteria. A more extensive survey targeted these two symbiont types through diagnostic PCR in 1225 strains representing 225 species from 32 species groups. Of these, 19 species were infected by Wolbachia while only 3 species had Spiroplasma. Several new strains of Wolbachia and Spiroplasma were discovered, including ones divergent from any reported to date. The phylogenetic distribution of Wolbachia and Spiroplasma in Drosophila is discussed. PMID:16783009

  12. Gut microbiota and metabolic syndrome

    PubMed Central

    Festi, Davide; Schiumerini, Ramona; Eusebi, Leonardo Henry; Marasco, Giovanni; Taddia, Martina; Colecchia, Antonio

    2014-01-01

    Gut microbiota exerts a significant role in the pathogenesis of the metabolic syndrome, as confirmed by studies conducted both on humans and animal models. Gut microbial composition and functions are strongly influenced by diet. This complex intestinal “superorganism” seems to affect host metabolic balance modulating energy absorption, gut motility, appetite, glucose and lipid metabolism, as well as hepatic fatty storage. An impairment of the fine balance between gut microbes and host’s immune system could culminate in the intestinal translocation of bacterial fragments and the development of “metabolic endotoxemia”, leading to systemic inflammation and insulin resistance. Diet induced weight-loss and bariatric surgery promote significant changes of gut microbial composition, that seem to affect the success, or the inefficacy, of treatment strategies. Manipulation of gut microbiota through the administration of prebiotics or probiotics could reduce intestinal low grade inflammation and improve gut barrier integrity, thus, ameliorating metabolic balance and promoting weight loss. However, further evidence is needed to better understand their clinical impact and therapeutic use. PMID:25473159

  13. Magnesium and Embryonic Development

    PubMed Central

    Komiya, Yuko; Su, Li-Ting; Chen, Hsiang-Chin; Habas, Raymond; Runnels, Loren W.

    2014-01-01

    Important for energy metabolism, neurotransmission, bone stability, and other cellular functions, Mg2+ has well-established and undisputedly critical roles in adult tissues. Its contributions to early embryonic development are less clearly understood. For decades it has been known that gestational Mg2+ deficiency in rodents produces teratogenic effects. More recent studies have linked deficiency in this vital cation to birth defects in humans, including spina bifida, a neural fold closure defect in humans that occurs at an average rate of 1 per 1000 pregnancies. The first suggestion that Mg2+ may be playing a more specific role in early development arose from studies of the TRPM7 and TRPM6 ion channels. TRPM7 and TRPM6 are divalent-selective ion channels in possession of their own kinase domains that have been implicated in the control of Mg2+ homeostasis in vertebrates. Disruption of the functions of these ion channels in mice as well as in frogs interferes with gastrulation, a pivotal process during early embryonic development that executes the emergence of the body plan and closure of the neural tube. Surprisingly, gastrulation defects produced by depletion of TRPM7 can be prevented by Mg2+ supplementation, indicating an essential role for Mg2+ in gastrulation and neural fold closure. The aim of this review is to summarize the data emerging from molecular genetic, biochemical and electrophysiological studies of TRPM6 and TRPM7 and provide a model of how Mg2+, through these unique channel-kinases, may be impacting early embryonic development. PMID:24721994

  14. Microinjection wound assay and in vivo localization of epidermal wound response reporters in Drosophila embryos.

    PubMed

    Juarez, Michelle T; Patterson, Rachel A; Li, Wilson; McGinnis, William

    2013-01-01

    The Drosophila embryo develops a robust epidermal layer that serves both to protect the internal cells from a harsh external environment as well as to maintain cellular homeostasis. Puncture injury with glass needles provides a direct method to trigger a rapid epidermal wound response that activates wound transcriptional reporters, which can be visualized by a localized reporter signal in living embryos or larvae. Puncture or laser injury also provides signals that promote the recruitment of hemocytes to the wound site. Surprisingly, severe (through and through) puncture injury in late stage embryos only rarely disrupts normal embryonic development, as greater than 90% of such wounded embryos survive to adulthood when embryos are injected in an oil medium that minimizes immediate leakage of hemolymph from puncture sites. The wound procedure does require micromanipulation of the Drosophila embryos, including manual alignment of the embryos on agar plates and transfer of the aligned embryos to microscope slides. The Drosophila epidermal wound response assay provides a quick system to test the genetic requirements of a variety of biological functions that promote wound healing, as well as a way to screen for potential chemical compounds that promote wound healing. The short life cycle and easy culturing routine make Drosophila a powerful model organism. Drosophila clean wound healing appears to coordinate the epidermal regenerative response, with the innate immune response, in ways that are still under investigation, which provides an excellent system to find conserved regulatory mechanisms common to Drosophila and mammalian epidermal wounding. PMID:24300796

  15. biniou (FoxF), a central component in a regulatory network controlling visceral mesoderm development and midgut morphogenesis in Drosophila

    PubMed Central

    Zaffran, Stephane; Küchler, Axel; Lee, Hsiu-Hsiang; Frasch, Manfred

    2001-01-01

    The subdivision of the lateral mesoderm into a visceral (splanchnic) and a somatic layer is a crucial event during early mesoderm development in both arthropod and vertebrate embryos. In Drosophila, this subdivision leads to the differential development of gut musculature versus body wall musculature. Here we report that biniou, the sole Drosophila representative of the FoxF subfamily of forkhead domain genes, has a key role in the development of the visceral mesoderm and the derived gut musculature. biniou expression is activated in the trunk visceral mesoderm primordia downstream of dpp, tinman, and bagpipe and is maintained in all types of developing gut muscles. We show that biniou activity is essential for maintaining the distinction between splanchnic and somatic mesoderm and for differentiation of the splanchnic mesoderm into midgut musculature. biniou is required not only for the activation of differentiation genes that are expressed ubiquitously in the trunk visceral mesoderm but also for the expression of dpp in parasegment 7, which governs proper midgut morphogenesis. Activation of dpp is mediated by specific Biniou binding sites in a dpp enhancer element, which suggests that Biniou serves as a tissue-specific cofactor of homeotic gene products in visceral mesoderm patterning. Based upon these and other data, we propose that the splanchnic mesoderm layers in Drosophila and vertebrate embryos are homologous structures whose development into gut musculature and other visceral organs is critically dependent on FoxF genes. PMID:11691840

  16. Flipped GUT inflation

    SciTech Connect

    Ellis, John; Gonzalo, Tomás E.; Harz, Julia; Huang, Wei-Chih

    2015-03-23

    We analyse the prospects for constructing hybrid models of inflation that provide a dynamical realisation of the apparent closeness between the supersymmetric GUT scale and the possible scale of cosmological inflation. In the first place, we consider models based on the flipped SU(5)×U(1) gauge group, which has no magnetic monopoles. In one model, the inflaton is identified with a sneutrino field, and in the other model it is a gauge singlet. In both cases we find regions of the model parameter spaces that are compatible with the experimental magnitudes of the scalar perturbations, A{sub s}, and the tilt in the scalar perturbation spectrum, n{sub s}, as well as with an indicative upper limit on the tensor-to-scalar perturbation ratio, r. We also discuss embeddings of these models into SO(10), which is broken at a higher scale so that its monopoles are inflated away.

  17. A fatty gut feeling

    PubMed Central

    Piomelli, Daniele

    2013-01-01

    The absorptive epithelium of the proximal small intestine converts oleic acid released during fat digestion into oleoylethanolamide (OEA), an endogenous high-affinity agonist of peroxisome proliferator-activated receptor-α (PPAR-α). OEA interacts with this receptor to cause a state of satiety characterized by prolonged inter-meal intervals and reduced feeding frequency. The two main branches of the autonomic nervous system, sympathetic and parasympathetic, contribute to this effect: the former by enabling OEA mobilization in the gut and the latter by relaying the OEA signal to brain structures, such as the hypothalamus, that are involved in feeding regulation. OEA signaling may be a key component of the physiological system devoted to the monitoring of dietary fat intake, and its dysfunction might contribute to overweight and obesity. PMID:23567058

  18. The gut microbiome.

    PubMed

    Actis, Giovanni C

    2014-01-01

    Since the discovery and use of the microscope in the 17(th) century, we know that we host trillions of micro-organisms mostly in the form of bacteria indwelling the "barrier organs" skin, gut, and airways. They exert regulatory functions, are in a continuous dialogue with the intestinal epithelia, influence energy handling, produce nutrients, and may cause diabetes and obesity. The human microbiome has developed by modulating or avoiding inflammatory responses; the host senses bacterial presence through cell surface sensors (the Toll-like receptors) as well as by refining mucous barriers as passive defense mechanisms. The cell density and composition of the microbiome are variable and multifactored. The way of delivery establishes the type of initial flora; use of antibiotics is another factor; diet composition after weaning will shape the adult's microbiome composition, depending on the subject's life-style. Short-chain fatty acids participate in the favoring action exerted by microbiome in the pathogenesis of type-2 diabetes and obesity. Clinical observation has pinpointed a sharp rise of various dysimmune conditions in the last decades, including IBD and rheumatoid arthritis, changes that outweigh the input of simple heritability. It is nowadays proposed that the microbiome, incapable to keep up with the changes of our life-style and feeding sources in the past few decades might have contributed to these immune imbalances, finding itself inadequate to handle the changed gut environment. Another pathway to pathology is the rise of directly pathogenic phyla within a given microbiome: growth of adherent E. coli, of C. concisus, and of C. jejuni, might be examples of causes of local enteropathy, whereas the genus Prevotella copri is now suspected to be linked to rise of arthritic disorders. Inflammasomes are required to shape a non colitogenic flora. Treatment of IBD and infectious enteritides by the use of fecal transplant is warranted by this knowledge. PMID

  19. Links between diet, gut microbiota composition and gut metabolism.

    PubMed

    Flint, Harry J; Duncan, Sylvia H; Scott, Karen P; Louis, Petra

    2015-02-01

    The gut microbiota and its metabolic products interact with the host in many different ways, influencing gut homoeostasis and health outcomes. The species composition of the gut microbiota has been shown to respond to dietary change, determined by competition for substrates and by tolerance of gut conditions. Meanwhile, the metabolic outputs of the microbiota, such as SCFA, are influenced both by the supply of dietary components and via diet-mediated changes in microbiota composition. There has been significant progress in identifying the phylogenetic distribution of pathways responsible for formation of particular metabolites among human colonic bacteria, based on combining cultural microbiology and sequence-based approaches. Formation of butyrate and propionate from hexose sugars, for example, can be ascribed to different bacterial groups, although propionate can be formed via alternative pathways from deoxy-sugars and from lactate by a few species. Lactate, which is produced by many gut bacteria in pure culture, can also be utilised by certain Firmicutes to form butyrate, and its consumption may be important for maintaining a stable community. Predicting the impact of diet upon such a complex and interactive system as the human gut microbiota not only requires more information on the component groups involved but, increasingly, the integration of such information through modelling approaches. PMID:25268552

  20. GUTs and supersymmetric GUTs in the very early universe

    SciTech Connect

    Ellis, J.

    1982-10-01

    This talk is intended as background material for many of the other talks treating the possible applications of GUTs to the very early universe. I start with a review of the present theoretical and phenomenological status of GUTs before going on to raise some new issues for their prospective cosmological applications which arise in supersymmetric (susy) GUTs. The first section is an update on conventional GUTs, which is followed by a reminder of some of the motivations for going supersymmetric. There then follows a simple primer on susy and a discussion of the structure and phenomenology of simple sysy GUTs. Finally we come to the cosmological issues, including problems arising from the degeneracy of susy minima, baryosynthesis and supersymmetric inflation, the possibility that gravity is an essential complication in constructing susy GUTs and discussing their cosmology, and the related question of what mass range is allowed for the gravitino. Several parts of this write-up contain new material which has emerged either during the Workshop or subsequently. They are included here for completeness and the convenience of the prospective reader. Wherever possible, these anachronisms will be flagged so as to keep straight the historical record.

  1. Phylogenetic Characterization of Two Novel Commensal Bacteria Involved with Innate Immune Homeostasis in Drosophila melanogaster▿

    PubMed Central

    Roh, Seong Woon; Nam, Young-Do; Chang, Ho-Won; Kim, Kyoung-Ho; Kim, Min-Soo; Ryu, Ji-Hwan; Kim, Sung-Hee; Lee, Won-Jae; Bae, Jin-Woo

    2008-01-01

    During a previous study on the molecular interaction between commensal bacteria and host gut immunity, two novel bacterial strains, A911T and G707T, were isolated from the gut of Drosophila melanogaster. In this study, these strains were characterized in a polyphasic taxonomic study using phenotypic, genetic, and chemotaxonomic analyses. We show that the strains represent novel species in the family Acetobacteraceae. Strain G707T, a highly pathogenic organism, represents a new species in the genus Gluconobacter, “Gluconobacter morbifer” sp. nov. (type strain G707 = KCTC 22116T = JCM 15512T). Strain A911T, dominantly present in the normal Drosphila gut community, represents a novel genus and species, designated “Commensalibacter intestini” gen. nov., sp. nov. (type strain A911 = KCTC 22117T = JCM 15511T). PMID:18723651

  2. Aging Studies in Drosophila melanogaster

    PubMed Central

    Sun, Yaning; Yolitz, Jason; Wang, Cecilia; Spangler, Edward; Zhan, Ming; Zou, Sige

    2015-01-01

    Summary Drosophila is a genetically tractable system ideal for investigating the mechanisms of aging and developing interventions for promoting healthy aging. Here we describe methods commonly used in Drosophila aging research. These include basic approaches for preparation of diets and measurements of lifespan, food intake and reproductive output. We also describe some commonly used assays to measure changes in physiological and behavioral functions of Drosophila in aging, such as stress resistance and locomotor activity. PMID:23929099

  3. Functional Evolution of cis-Regulatory Modules at a Homeotic Gene in Drosophila

    PubMed Central

    Schiller, Benjamin J.; Bae, Esther; Tran, Diana A.; Shur, Andrey S.; Allen, John M.; Rau, Christoph; Bender, Welcome; Fisher, William W.; Celniker, Susan E.; Drewell, Robert A.

    2009-01-01

    It is a long-held belief in evolutionary biology that the rate of molecular evolution for a given DNA sequence is inversely related to the level of functional constraint. This belief holds true for the protein-coding homeotic (Hox) genes originally discovered in Drosophila melanogaster. Expression of the Hox genes in Drosophila embryos is essential for body patterning and is controlled by an extensive array of cis-regulatory modules (CRMs). How the regulatory modules functionally evolve in different species is not clear. A comparison of the CRMs for the Abdominal-B gene from different Drosophila species reveals relatively low levels of overall sequence conservation. However, embryonic enhancer CRMs from other Drosophila species direct transgenic reporter gene expression in the same spatial and temporal patterns during development as their D. melanogaster orthologs. Bioinformatic analysis reveals the presence of short conserved sequences within defined CRMs, representing gap and pair-rule transcription factor binding sites. One predicted binding site for the gap transcription factor KRUPPEL in the IAB5 CRM was found to be altered in Superabdominal (Sab) mutations. In Sab mutant flies, the third abdominal segment is transformed into a copy of the fifth abdominal segment. A model for KRUPPEL-mediated repression at this binding site is presented. These findings challenge our current understanding of the relationship between sequence evolution at the molecular level and functional activity of a CRM. While the overall sequence conservation at Drosophila CRMs is not distinctive from neighboring genomic regions, functionally critical transcription factor binding sites within embryonic enhancer CRMs are highly conserved. These results have implications for understanding mechanisms of gene expression during embryonic development, enhancer function, and the molecular evolution of eukaryotic regulatory modules. PMID:19893611

  4. Identification of Drosophila Mutants Affecting Defense to an Entomopathogenic Fungus

    PubMed Central

    Lu, Hsiao-Ling; Wang, Jonathan B.; Brown, Markus A.; Euerle, Christopher; St. Leger, Raymond J.

    2015-01-01

    Fungi cause the majority of insect disease. However, to date attempts to model host–fungal interactions with Drosophila have focused on opportunistic human pathogens. Here, we performed a screen of 2,613 mutant Drosophila lines to identify host genes affecting susceptibility to the natural insect pathogen Metarhizium anisopliae (Ma549). Overall, 241 (9.22%) mutant lines had altered resistance to Ma549. Life spans ranged from 3.0 to 6.2 days, with females being more susceptible than males in all lines. Speed of kill correlated with within-host growth and onset of sporulation, but total spore production is decoupled from host genotypes. Results showed that mutations affected the ability of Drosophila to restrain rather than tolerate infections and suggested trade-offs between antifungal and antibacterial genes affecting cuticle and gut structural barriers. Approximately, 13% of mutations where in genes previously associated with host pathogen interactions. These encoded fast-acting immune responses including coagulation, phagocytosis, encapsulation and melanization but not the slow-response induction of anti-fungal peptides. The non-immune genes impact a wide variety of biological functions, including behavioral traits. Many have human orthologs already implicated in human disorders; while others were mutations in protein and non-protein coding genes for which disease resistance was the first biological annotation. PMID:26202798

  5. Gut Microbiota: The Brain Peacekeeper

    PubMed Central

    Mu, Chunlong; Yang, Yuxiang; Zhu, Weiyun

    2016-01-01

    Gut microbiota regulates intestinal and extraintestinal homeostasis. Accumulating evidence suggests that the gut microbiota may also regulate brain function and behavior. Results from animal models indicate that disturbances in the composition and functionality of some microbiota members are associated with neurophysiological disorders, strengthening the idea of a microbiota–gut–brain axis and the role of microbiota as a “peacekeeper” in the brain health. Here, we review recent discoveries on the role of the gut microbiota in central nervous system-related diseases. We also discuss the emerging concept of the bidirectional regulation by the circadian rhythm and gut microbiota, and the potential role of the epigenetic regulation in neuronal cell function. Microbiome studies are also highlighted as crucial in the development of targeted therapies for neurodevelopmental disorders. PMID:27014255

  6. ERK signaling couples nutrient status to antiviral defense in the insect gut.

    PubMed

    Xu, Jie; Hopkins, Kaycie; Sabin, Leah; Yasunaga, Ari; Subramanian, Harry; Lamborn, Ian; Gordesky-Gold, Beth; Cherry, Sara

    2013-09-10

    A unique facet of arthropod-borne virus (arbovirus) infection is that the pathogens are orally acquired by an insect vector during the taking of a blood meal, which directly links nutrient acquisition and pathogen challenge. We show that the nutrient responsive ERK pathway is both induced by and restricts disparate arboviruses in Drosophila intestines, providing insight into the molecular determinants of the antiviral "midgut barrier." Wild-type flies are refractory to oral infection by arboviruses, including Sindbis virus and vesicular stomatitis virus, but this innate restriction can be overcome chemically by oral administration of an ERK pathway inhibitor or genetically via the specific loss of ERK in Drosophila intestinal epithelial cells. In addition, we found that vertebrate insulin, which activates ERK in the mosquito gut during a blood meal, restricts viral infection in Drosophila cells and against viral invasion of the insect gut epithelium. We find that ERK's antiviral signaling activity is likely conserved in Aedes mosquitoes, because genetic or pharmacologic manipulation of the ERK pathway affects viral infection of mosquito cells. These studies demonstrate that ERK signaling has a broadly antiviral role in insects and suggest that insects take advantage of cross-species signals in the meal to trigger antiviral immunity. PMID:23980175

  7. ERK signaling couples nutrient status to antiviral defense in the insect gut

    PubMed Central

    Xu, Jie; Hopkins, Kaycie; Sabin, Leah; Yasunaga, Ari; Subramanian, Harry; Lamborn, Ian; Gordesky-Gold, Beth; Cherry, Sara

    2013-01-01

    A unique facet of arthropod-borne virus (arbovirus) infection is that the pathogens are orally acquired by an insect vector during the taking of a blood meal, which directly links nutrient acquisition and pathogen challenge. We show that the nutrient responsive ERK pathway is both induced by and restricts disparate arboviruses in Drosophila intestines, providing insight into the molecular determinants of the antiviral “midgut barrier.” Wild-type flies are refractory to oral infection by arboviruses, including Sindbis virus and vesicular stomatitis virus, but this innate restriction can be overcome chemically by oral administration of an ERK pathway inhibitor or genetically via the specific loss of ERK in Drosophila intestinal epithelial cells. In addition, we found that vertebrate insulin, which activates ERK in the mosquito gut during a blood meal, restricts viral infection in Drosophila cells and against viral invasion of the insect gut epithelium. We find that ERK’s antiviral signaling activity is likely conserved in Aedes mosquitoes, because genetic or pharmacologic manipulation of the ERK pathway affects viral infection of mosquito cells. These studies demonstrate that ERK signaling has a broadly antiviral role in insects and suggest that insects take advantage of cross-species signals in the meal to trigger antiviral immunity. PMID:23980175

  8. A Circadian Clock Gene, Cry, Affects Heart Morphogenesis and Function in Drosophila as Revealed by Optical Coherence Microscopy

    PubMed Central

    Zeng, Xianxu; Tate, Rebecca E.; McKee, Mary L.; Capen, Diane E.; Zhang, Zhan; Tanzi, Rudolph E.; Zhou, Chao

    2015-01-01

    Circadian rhythms are endogenous, entrainable oscillations of physical, mental and behavioural processes in response to local environmental cues such as daylight, which are present in the living beings, including humans. Circadian rhythms have been related to cardiovascular function and pathology. However, the role that circadian clock genes play in heart development and function in a whole animal in vivo are poorly understood. The Drosophila cryptochrome (dCry) is a circadian clock gene that encodes a major component of the circadian clock negative feedback loop. Compared to the embryonic stage, the relative expression levels of dCry showed a significant increase (>100-fold) in Drosophila during the pupa and adult stages. In this study, we utilized an ultrahigh resolution optical coherence microscopy (OCM) system to perform non-invasive and longitudinal analysis of functional and morphological changes in the Drosophila heart throughout its post-embryonic lifecycle for the first time. The Drosophila heart exhibited major morphological and functional alterations during its development. Notably, heart rate (HR) and cardiac activity period (CAP) of Drosophila showed significant variations during the pupa stage, when heart remodeling took place. From the M-mode (2D + time) OCM images, cardiac structural and functional parameters of Drosophila at different developmental stages were quantitatively determined. In order to study the functional role of dCry on Drosophila heart development, we silenced dCry by RNAi in the Drosophila heart and mesoderm, and quantitatively measured heart morphology and function in those flies throughout its development. Silencing of dCry resulted in slower HR, reduced CAP, smaller heart chamber size, pupal lethality and disrupted posterior segmentation that was related to increased expression of a posterior compartment protein, wingless. Collectively, our studies provided novel evidence that the circadian clock gene, dCry, plays an essential

  9. A Circadian Clock Gene, Cry, Affects Heart Morphogenesis and Function in Drosophila as Revealed by Optical Coherence Microscopy.

    PubMed

    Alex, Aneesh; Li, Airong; Zeng, Xianxu; Tate, Rebecca E; McKee, Mary L; Capen, Diane E; Zhang, Zhan; Tanzi, Rudolph E; Zhou, Chao

    2015-01-01

    Circadian rhythms are endogenous, entrainable oscillations of physical, mental and behavioural processes in response to local environmental cues such as daylight, which are present in the living beings, including humans. Circadian rhythms have been related to cardiovascular function and pathology. However, the role that circadian clock genes play in heart development and function in a whole animal in vivo are poorly understood. The Drosophila cryptochrome (dCry) is a circadian clock gene that encodes a major component of the circadian clock negative feedback loop. Compared to the embryonic stage, the relative expression levels of dCry showed a significant increase (>100-fold) in Drosophila during the pupa and adult stages. In this study, we utilized an ultrahigh resolution optical coherence microscopy (OCM) system to perform non-invasive and longitudinal analysis of functional and morphological changes in the Drosophila heart throughout its post-embryonic lifecycle for the first time. The Drosophila heart exhibited major morphological and functional alterations during its development. Notably, heart rate (HR) and cardiac activity period (CAP) of Drosophila showed significant variations during the pupa stage, when heart remodeling took place. From the M-mode (2D + time) OCM images, cardiac structural and functional parameters of Drosophila at different developmental stages were quantitatively determined. In order to study the functional role of dCry on Drosophila heart development, we silenced dCry by RNAi in the Drosophila heart and mesoderm, and quantitatively measured heart morphology and function in those flies throughout its development. Silencing of dCry resulted in slower HR, reduced CAP, smaller heart chamber size, pupal lethality and disrupted posterior segmentation that was related to increased expression of a posterior compartment protein, wingless. Collectively, our studies provided novel evidence that the circadian clock gene, dCry, plays an essential

  10. Two Ligands Signal Through the Drosophila PDGF/VEGF Receptor to Ensure Proper Salivary Gland Positioning

    PubMed Central

    Harris, Katherine E.; Schnittke, Nikolai; Beckendorf, Steven K.

    2009-01-01

    SUMMARY The Drosophila embryonic salivary gland is a migrating tissue that undergoes a stereotypic pattern of migration into the embryo. We demonstrate that the migratory path of the salivary gland requires the PDGF/VEGF pathway. The PDGF/VEGF receptor, Pvr, is strongly expressed in the salivary glands, and Pvr mutations cause abnormal ventral curving of the glands, suggesting that Pvr is involved in gland migration. Although the Pvr ligands, Pvf1 and Pvf2, have distinct expression patterns in the Drosophila embryo, mutations for either one of the ligands result in salivary gland migration defects similar to those seen in embryos that lack Pvr. Rescue experiments indicate that the PDGF/VEGF pathway functions autonomously in the salivary gland. The results of this study demonstrate that the Drosophila PDGF/VEGF pathway is essential for proper positioning of the salivary glands. PMID:17462868

  11. De Novo Assembly and Characterization of Early Embryonic Transcriptome of the Horseshoe Crab Tachypleus tridentatus.

    PubMed

    Chen, Mingliang; Wang, Chenying; Wang, Wei; Ji, Gubiao; Hu, Bin; Du, Mi; Liu, Guosheng; Li, Zengpeng; Wang, Weiyi; Lin, Xiangzhi; Zheng, Weibing; Chen, Jianming

    2016-01-01

    The horseshoe crab Tachypleus tridentatus is a unique marine species and a potential model for marine invertebrate. Limited genomic and transcriptional data are currently available to understand the molecular mechanisms underlying the embryonic development of T. tridentatus. Here, we reported for the first time the de novo transcriptome assembly for T. tridentatus at embryonic developmental stage using Illumina RNA-seq platform. Approximate 38 million reads were obtained and further assembled into 133,212 unigenes. Sequence homology analysis against public databases revealed that 33,796 unigenes could be annotated with gene descriptions. Of the annotated unigenes, we identified a number of key components of several conserved metazoan signaling pathways (Hedgehog, Wnt, TGF-beta and Notch pathways) and other important regulatory genes involved in embryonic development. Targeted searching of Pax family genes which play critical roles in the formation of tissue and organ during embryonic development identified a complete set of Pax family genes. Moreover, the full length T. tridentatus Pax1/9a (TtPax1/9a) and Pax1/9b (TtPax1/9b) cDNA sequences were determined based on the transcriptome, demonstrating the immediate application of our database. Using quantitative real time PCR, we analyzed the expression patterns of TtPax1/9a and TtPax1/9b in different tissues of horseshoe crab. Taking advantage of Drosophila model, we further found that TtPax1/9b, but not TtPax1/9a, can partly rescue the Drosophila homolog Poxm dysfunction-caused lethality at the larval stage. Our study provides the embryonic transcriptome of T. tridentatus which could be immediately used for gene discovery and characterization, functional genomics studies in T. tridentatus. This transcriptome database will also facilitate the investigations of molecular mechanisms underlying embryonic development of T. tridentatus and other marine arthropods as well. PMID:26731763

  12. De Novo Assembly and Characterization of Early Embryonic Transcriptome of the Horseshoe Crab Tachypleus tridentatus

    PubMed Central

    Ji, Gubiao; Hu, Bin; Du, Mi; Liu, Guosheng; Li, Zengpeng; Wang, Weiyi; Lin, Xiangzhi; Zheng, Weibing; Chen, Jianming

    2016-01-01

    The horseshoe crab Tachypleus tridentatus is a unique marine species and a potential model for marine invertebrate. Limited genomic and transcriptional data are currently available to understand the molecular mechanisms underlying the embryonic development of T. tridentatus. Here, we reported for the first time the de novo transcriptome assembly for T. tridentatus at embryonic developmental stage using Illumina RNA-seq platform. Approximate 38 million reads were obtained and further assembled into 133,212 unigenes. Sequence homology analysis against public databases revealed that 33,796 unigenes could be annotated with gene descriptions. Of the annotated unigenes, we identified a number of key components of several conserved metazoan signaling pathways (Hedgehog, Wnt, TGF-beta and Notch pathways) and other important regulatory genes involved in embryonic development. Targeted searching of Pax family genes which play critical roles in the formation of tissue and organ during embryonic development identified a complete set of Pax family genes. Moreover, the full length T. tridentatus Pax1/9a (TtPax1/9a) and Pax1/9b (TtPax1/9b) cDNA sequences were determined based on the transcriptome, demonstrating the immediate application of our database. Using quantitative real time PCR, we analyzed the expression patterns of TtPax1/9a and TtPax1/9b in different tissues of horseshoe crab. Taking advantage of Drosophila model, we further found that TtPax1/9b, but not TtPax1/9a, can partly rescue the Drosophila homolog Poxm dysfunction-caused lethality at the larval stage. Our study provides the embryonic transcriptome of T. tridentatus which could be immediately used for gene discovery and characterization, functional genomics studies in T. tridentatus. This transcriptome database will also facilitate the investigations of molecular mechanisms underlying embryonic development of T. tridentatus and other marine arthropods as well. PMID:26731763

  13. Gut Microbiome and Colorectal Adenomas

    PubMed Central

    Dulal, Santosh; Keku, Temitope O.

    2015-01-01

    The trillions of bacteria that naturally reside in the human gut collectively constitute the complex system known the gut microbiome, a vital player for the host’s homeostasis and health. However, there is mounting evidence that dysbiosis, a state of pathological imbalance in the gut microbiome is present in many disease states. In this review, we present recent insights concerning the gut microbiome’s contribution to the development of colorectal adenomas and the subsequent progression to colorectal cancer (CRC). In the United States alone, CRC is the second leading cause of cancer deaths. As a result, there is a high interest in identifying risk factors for adenomas, which are intermediate precursors to CRC. Recent research on CRC and the microbiome suggest that modulation of the gut bacterial composition and structure may be useful in preventing adenomas and CRC. We highlight the known risk factors for colorectal adenomas and the potential mechanisms by which microbial dysbiosis may contribute to the etiology of CRC. We also underscore novel findings from recent studies on the gut microbiota and colorectal adenomas along with current knowledge gaps. Understanding the microbiome may provide promising new directions towards novel diagnostic tools, biomarkers, and therapeutic interventions for CRC. PMID:24855012

  14. Gut Microbes, Diet, and Cancer

    PubMed Central

    Hullar, Meredith A. J.; Burnett-Hartman, Andrea N.

    2014-01-01

    An expanding body of evidence supports a role for gut microbes in the etiology of cancer. Previously, the focus was on identifying individual bacterial species that directly initiate or promote gastrointestinal malignancies; however, the capacity of gut microbes to influence systemic inflammation and other downstream pathways suggests that the gut microbial community may also affect risk of cancer in tissues outside of the gastrointestinal tract. Functional contributions of the gut microbiota that may influence cancer susceptibility in the broad sense include (1) harvesting otherwise inaccessible nutrients and/or sources of energy from the diet (i.e., fermentation of dietary fibers and resistant starch); (2) metabolism of xenobiotics, both potentially beneficial or detrimental (i.e., dietary constituents, drugs, carcinogens, etc.); (3) renewal of gut epithelial cells and maintenance of mucosal integrity; and (4) affecting immune system development and activity. Understanding the complex and dynamic interplay between the gut microbiome, host immune system, and dietary exposures may help elucidate mechanisms for carcinogenesis and guide future cancer prevention and treatment strategies. PMID:24114492

  15. Gut dysfunction in Parkinson's disease.

    PubMed

    Mukherjee, Adreesh; Biswas, Atanu; Das, Shyamal Kumar

    2016-07-01

    Early involvement of gut is observed in Parkinson's disease (PD) and symptoms such as constipation may precede motor symptoms. α-Synuclein pathology is extensively evident in the gut and appears to follow a rostrocaudal gradient. The gut may act as the starting point of PD pathology with spread toward the central nervous system. This spread of the synuclein pathology raises the possibility of prion-like propagation in PD pathogenesis. Recently, the role of gut microbiota in PD pathogenesis has received attention and some phenotypic correlation has also been shown. The extensive involvement of the gut in PD even in its early stages has led to the evaluation of enteric α-synuclein as a possible biomarker of early PD. The clinical manifestations of gastrointestinal dysfunction in PD include malnutrition, oral and dental disorders, sialorrhea, dysphagia, gastroparesis, constipation, and defecatory dysfunction. These conditions are quite distressing for the patients and require relevant investigations and adequate management. Treatment usually involves both pharmacological and non-pharmacological measures. One important aspect of gut dysfunction is its contribution to the clinical fluctuations in PD. Dysphagia and gastroparesis lead to inadequate absorption of oral anti-PD medications. These lead to response fluctuations, particularly delayed-on and no-on, and there is significant relationship between levodopa pharmacokinetics and gastric emptying in patients with PD. Therefore, in such cases, alternative routes of administration or drug delivery systems may be required. PMID:27433087

  16. Probiotics, gut microbiota and health.

    PubMed

    Butel, M-J

    2014-01-01

    The human gut is a huge complex ecosystem where microbiota, nutrients, and host cells interact extensively, a process crucial for the gut homeostasis and host development with a real partnership. The various bacterial communities that make up the gut microbiota have many functions including metabolic, barrier effect, and trophic functions. Hence, any dysbiosis could have negative consequences in terms of health and many diseases have been associated to impairment of the gut microbiota. These close relationships between gut microbiota, health, and disease, have led to great interest in using probiotics (i.e. live micro-organisms), or prebiotics (i.e. non-digestible substrates) to positively modulate the gut microbiota to prevent or treat some diseases. This review focuses on probiotics, their mechanisms of action, safety, and major health benefits. Health benefits remain to be proven in some indications, and further studies on the best strain(s), dose, and algorithm of administration to be used are needed. Nevertheless, probiotic administration seems to have a great potential in terms of health that justifies more research. PMID:24290962

  17. Gut microbes, diet, and cancer.

    PubMed

    Hullar, Meredith A J; Burnett-Hartman, Andrea N; Lampe, Johanna W

    2014-01-01

    An expanding body of evidence supports a role for gut microbes in the etiology of cancer. Previously, the focus was on identifying individual bacterial species that directly initiate or promote gastrointestinal malignancies; however, the capacity of gut microbes to influence systemic inflammation and other downstream pathways suggests that the gut microbial community may also affect risk of cancer in tissues outside of the gastrointestinal tract. Functional contributions of the gut microbiota that may influence cancer susceptibility in the broad sense include (1) harvesting otherwise inaccessible nutrients and/or sources of energy from the diet (i.e., fermentation of dietary fibers and resistant starch); (2) metabolism of xenobiotics, both potentially beneficial or detrimental (i.e., dietary constituents, drugs, carcinogens, etc.); (3) renewal of gut epithelial cells and maintenance of mucosal integrity; and (4) affecting immune system development and activity. Understanding the complex and dynamic interplay between the gut microbiome, host immune system, and dietary exposures may help elucidate mechanisms for carcinogenesis and guide future cancer prevention and treatment strategies. PMID:24114492

  18. Gut dysfunction in Parkinson's disease

    PubMed Central

    Mukherjee, Adreesh; Biswas, Atanu; Das, Shyamal Kumar

    2016-01-01

    Early involvement of gut is observed in Parkinson’s disease (PD) and symptoms such as constipation may precede motor symptoms. α-Synuclein pathology is extensively evident in the gut and appears to follow a rostrocaudal gradient. The gut may act as the starting point of PD pathology with spread toward the central nervous system. This spread of the synuclein pathology raises the possibility of prion-like propagation in PD pathogenesis. Recently, the role of gut microbiota in PD pathogenesis has received attention and some phenotypic correlation has also been shown. The extensive involvement of the gut in PD even in its early stages has led to the evaluation of enteric α-synuclein as a possible biomarker of early PD. The clinical manifestations of gastrointestinal dysfunction in PD include malnutrition, oral and dental disorders, sialorrhea, dysphagia, gastroparesis, constipation, and defecatory dysfunction. These conditions are quite distressing for the patients and require relevant investigations and adequate management. Treatment usually involves both pharmacological and non-pharmacological measures. One important aspect of gut dysfunction is its contribution to the clinical fluctuations in PD. Dysphagia and gastroparesis lead to inadequate absorption of oral anti-PD medications. These lead to response fluctuations, particularly delayed-on and no-on, and there is significant relationship between levodopa pharmacokinetics and gastric emptying in patients with PD. Therefore, in such cases, alternative routes of administration or drug delivery systems may be required. PMID:27433087

  19. Gut Microbiota and Hepatocellular Carcinoma

    PubMed Central

    Tao, Xuemei; Wang, Ning; Qin, Wenxin

    2015-01-01

    Background Hepatocellular carcinoma (HCC) is a common complication of liver diseases such as those related to viral hepatitis and liver cirrhosis. The gut-liver axis is gaining increasing attention as a key pathophysiological mechanism responsible for the progression of HCC. Here, we will review the data from the published literature to address the association between HCC and gut microbiota. Summary The presence of high levels of endotoxemia in the blood results in portal hypertension and ensuing hepatocyte damage, thus leading to the development of HCC. Probiotics can be used to treat or prevent the progression of HCC, because they may decrease the counts of gut microbiota and thus improve the endotoxemia. Key Message Increased bacterial translocation can result in endotoxemia, which may play a critical role in the progression of HCC. Modulation of the gut microbiota by probiotics may represent a new avenue for therapeutic intervention in HCC. Practical Implications Breakdown in intestinal barrier function and bacterial overgrowth are main events in the development of HCC. When the intestinal barrier function is disrupted, large amounts of bacterial products can enter the liver and induce inflammation through their receptors, leading to liver diseases. Altering the gut microflora has been proposed as an adjunctive therapy to reduce bacterial translocation and prevent progression of HCC. The purpose of this review is to discuss the relationship between gut microbiota and HCC in both pathogenesis and treatment by probiotics. PMID:26673641

  20. Drosophila by the dozen

    SciTech Connect

    Celniker, Susan E.; Hoskins, Roger A.

    2007-07-13

    This year's conference on Drosophila research illustratedwell the current focus of Drosophila genomics on the comprehensiveidentification of functional elements in the genome sequence, includingmRNA transcripts arising from multiple alternative start sites and splicesites, a multiplicity of noncoding transcripts and small RNAs,identification of binding sites for transcription factors, sequenceconservation in related species and sequence variation within species.Resources and technologies for genetics and functional genomics aresteadily being improved, including the building of collections oftransposon insertion mutants and hairpin constructs for RNA interference(RNAi). The conference also highlighted progress in the use of genomicinformation by many laboratories to study diverse aspects of biology andmodels of human disease. Here we will review a few highlights of especialinterest to readers of Genome Biology.

  1. The Drosophila Auditory System

    PubMed Central

    Boekhoff-Falk, Grace; Eberl, Daniel F.

    2013-01-01

    Development of a functional auditory system in Drosophila requires specification and differentiation of the chordotonal sensilla of Johnston’s organ (JO) in the antenna, correct axonal targeting to the antennal mechanosensory and motor center (AMMC) in the brain, and synaptic connections to neurons in the downstream circuit. Chordotonal development in JO is functionally complicated by structural, molecular and functional diversity that is not yet fully understood, and construction of the auditory neural circuitry is only beginning to unfold. Here we describe our current understanding of developmental and molecular mechanisms that generate the exquisite functions of the Drosophila auditory system, emphasizing recent progress and highlighting important new questions arising from research on this remarkable sensory system. PMID:24719289

  2. Nutrigenomics and gut health.

    PubMed

    Ferguson, Lynnette R; Shelling, Andrew N; Lauren, Denis; Heyes, Julian A; McNabb, Warren C

    2007-09-01

    Recognition of the interplay between genes and diet in development of disease and for maintenance of optimal metabolism has led to nutrigenomic or nutrigenetic approaches to personalising or individualising nutrition, with the potential of preventing, delaying, or reducing the symptoms of chronic diseases. Some of the development work has focussed on cardiovascular disease or type II diabetes mellitus, where various groups have identified potential diet-gene interactions. However, the available studies also emphasise the exponential increase in numbers of subjects necessary to recruit for clinical evaluation if we are to successfully provide informative high-dimensional datasets of genetic, nutrient, metabolomic (clinical), and other variables. There is also a significant bioinformatics challenge to analyze these. To add to the complexity, many of the pioneering studies had assumed that single nucleotide polymorphisms (SNPs) were the main source of human variability, but an increasing evidence base suggests the importance of more subtle gene regulatory mechanisms, including copy number variants. As an example, the risk of Inflammatory Bowel Disease (IBD) is associated with the inheritance of a number of contributory SNPs as well as with copy number variants of certain other genes. The variant forms of genes often result in disruptions to bacterial homeostasis mechanisms or to signal transduction of the intestinal epithelial cell of the host, and thereby to altered intestinal barrier function, and/or adaptive immune responses. The human gut microbiota is altered in individuals suffering from disorders such as IBD, and probiotic or prebiotic therapies or elemental diets may be beneficial to a high proportion of individuals through modifying the gut microbiota, and also modulating immune responses. New putative foods or dietary therapies may be identified through novel tissue culture screens, followed by further testing with in vivo animal models of human disease. A

  3. Identification of chromosomal regions involved in decapentaplegic function in Drosophila.

    PubMed Central

    Nicholls, R E; Gelbart, W M

    1998-01-01

    Signaling molecules of the transforming growth factor beta (TGF-beta) family contribute to numerous developmental processes in a variety of organisms. However, our understanding of the mechanisms which regulate the activity of and mediate the response to TGF-beta family members remains incomplete. The product of the Drosophila decapentaplegic (dpp) locus is a well-characterized member of this family. We have taken a genetic approach to identify factors required for TGF-beta function in Drosophila by testing for genetic interactions between mutant alleles of dpp and a collection of chromosomal deficiencies. Our survey identified two deficiencies that act as maternal enhancers of recessive embryonic lethal alleles of dpp. The enhanced individuals die with weakly ventralized phenotypes. These phenotypes are consistent with a mechanism whereby the deficiencies deplete two maternally provided factors required for dpp's role in embryonic dorsal-ventral pattern formation. One of these deficiencies also appears to delete a factor required for dpp function in wing vein formation. These deficiencies remove material from the 54F-55A and 66B-66C polytene chromosomal regions, respectively. As neither of these regions has been previously implicated in dpp function, we propose that each of the deficiencies removes a novel factor or factors required for dpp function. PMID:9584097

  4. Hybrid Lethal Systems in the Drosophila Melanogaster Species Complex. I. the Maternal Hybrid Rescue (Mhr) Gene of Drosophila Simulans

    PubMed Central

    Sawamura, K.; Taira, T.; Watanabe, T. K.

    1993-01-01

    Hybrid females from Drosophila simulans females X Drosophila melanogaster males die as embryos while hybrid males from the reciprocal cross die as late larvae. The other two classes are sterile adults. Letting C, X, and Y designate egg cytoplasm, X, and Y chromosomes, respectively, and subscripts m and s stand for melanogaster and simulans, C(m)X(m)Y(s) males are lethal in the larval stage and are rescued by the previously reported genes, Lhr (Lethal hybrid rescue) in simulans or Hmr (Hybrid male rescue) in melanogaster. We report here another rescue gene located on the second chromosome of simulans, mhr (maternal hybrid rescue) that, when present in the mother, rescues C(s)X(m)X(s) females from embryonic lethality. It has been postulated that the hybrids not carrying the X(s) like C(m)X(m)Y(s) males are larval lethal and that the hybrids carrying both the C(s) and the X(m) like C(s)X(m)X(s) females are embryonic lethal. According to these postulates C(s)X(m)Y(s) males (obtained by mating attached-X simulans females to melanogaster males) should be doubly lethal, at both embryo and larval stages. When both rescuing genes are present, Hmr in the father and mhr in the mother, males of this genotype are fully viable, as predicted. PMID:8436276

  5. Mechanisms and functions of Nrf2 signaling in Drosophila.

    PubMed

    Pitoniak, Andrew; Bohmann, Dirk

    2015-11-01

    The Nrf2 transcription factor belongs to the Cap'n'collar family, named after the founding member of this group, the product of the Drosophila Cap'n'collar gene. The encoded protein, Cap'n'collar, abbreviated Cnc, offers a convenient and accessible model to study the structure, function, and biology of Nrf2 transcription factors at the organismic, tissular, cellular, and molecular levels, using the powerful genetic, genomic, and biochemical tools available in Drosophila. In this review we provide an account of the original identification of Cnc as a regulator of embryonic development. We then describe the discovery of Nrf2-like functions of Cnc and its role in acute stress signaling and aging. The establishment of Drosophila as a model organism in which the mechanisms and functions of Nrf2 signaling can be studied has led to several discoveries: the regulation of stem cell activity by an Nrf2-mediated redox mechanism, the interaction of Nrf2 with p62 and Myc in the control of tissue growth and the unfolded protein response, and more. Several of these more recent lines of investigation are highlighted. Model organisms such as the fly and the worm remain powerful experimental platforms that can help to unravel the many remaining puzzles regarding the role of Nrf2 and its relatives in controlling the physiology and maintaining the health of multicellular organisms. PMID:26117322

  6. Expression and Function of Scalloped During Drosophila Development

    PubMed Central

    Guss, Kirsten A.; Benson, Michael; Gubitosi, Nicholas; Brondell, Karrie; Broadie, Kendal; Skeath, James B.

    2013-01-01

    Background The scalloped (sd) and vestigial (vg) genes function together in Drosophila wing development. Little is known about sd protein (SD) expression during development, or whether sd and vg interact in other developing tissues. To begin to address these questions, we generated an anti-SD antibody. Results During embryogenesis, SD is expressed in both central and peripheral nervous systems, and the musculature. SD is also expressed in developing flight appendages. Despite SD expression herein, the peripheral nervous system, musculature, and dorsal limb primordia appeared generally normal in the absence of sd function. SD is also expressed in subsets of ventral nerve cord cells, including neuroblast 1–2 descendants and ventral unpaired median motor neurons (mVUMs). While sd function is not required to specify these neurons, it is necessary for the correct innervation of somatic muscles by the mVUMs. We also show that SD and VG are co-expressed in overlapping and distinctive subsets of cells in embryonic and larval tissues. Conclusions We describe the full breadth of SD expression during Drosophila embryogenesis, and identify a requirement for sd function in a subset of motor neurons. This work provides the necessary foundation for functional studies regarding the roles of sd during Drosophila development. PMID:23389965

  7. Microcephalin coordinates mitosis in the syncytial Drosophila embryo.

    PubMed

    Brunk, Kathrin; Vernay, Bertrand; Griffith, Elen; Reynolds, Natalie L; Strutt, David; Ingham, Philip W; Jackson, Andrew P

    2007-10-15

    Microcephalin (MCPH1) is mutated in primary microcephaly, an autosomal recessive human disorder of reduced brain size. It encodes a protein with three BRCT domains that has established roles in DNA damage signalling and the cell cycle, regulating chromosome condensation. Significant adaptive evolutionary changes in primate MCPH1 sequence suggest that changes in this gene could have contributed to the evolution of the human brain. To understand the developmental role of microcephalin we have studied its function in Drosophila. We report here that Drosophila MCPH1 is cyclically localised during the cell cycle, co-localising with DNA during interphase, but not with mitotic chromosomes. mcph1 mutant flies have a maternal effect lethal phenotype, due to mitotic arrest occurring in early syncytial cell cycles. Mitotic entry is slowed from the very first mitosis in such embryos, with prolonged prophase and metaphase stages; and frequent premature separation as well as detachment of centrosomes. As a consequence, centrosome and nuclear cycles become uncoordinated, resulting in arrested embryonic development. Phenotypic similarities with abnormal spindle (asp) and centrosomin (cnn) mutants (whose human orthologues are also mutated in primary microcephaly), suggest that further studies in the Drosophila embryo may establish a common developmental and cellular pathway underlying the human primary microcephaly phenotype. PMID:17895363

  8. Vitrification-based cryopreservation of Drosophila embryos

    SciTech Connect

    Schreuders, P.D.; Mazur, P.

    1994-12-31

    Currently, over 30,000 strains of Drosophila melanogaster are maintained by geneticists through regular transfer of breeding stocks. A more cost effective solution is to cryopreserve their embryos. Cooling and warming rates >10,000{degrees}C/min. are required to prevent chilling injury. To avoid the lethal intracellular ice normally produced at such high cooling rates, it is necessary to use {ge}50% (w/w) concentrations of glass-inducing solutes to vitrify the embryos. Differential scanning calorimetry (DSC) is used to develop and evaluate ethylene glycol and polyvinyl pyrrolidone based vitrification solutions. The resulting solution consists of 8.5M ethylene glycol + 10% polyvinylpyrrolidone in D-20 Drosophila culture medium. A two stage method is used for the introduction and concentration of these solutes within the embryo. The method reduces the exposure time to the solution and, consequently, reduces toxicity. Both DSC and freezing experiments suggest that, while twelve-hour embryos will vitrify using cooling rates >200{degrees}C/min., they will devitrify and be killed with even moderately rapid warming rates of {approximately}1,900{degrees}C/min. Very rapid warming ({approximately}100,000{degrees}C/min.) results in variable numbers of successfully cryopreserved embryos. This sensitivity to warming rite is typical of devitrification. The variability in survival is reduced using embryos of a precisely determined embryonic stage. The vitrification of the older, fifteen-hour, embryos yields an optimized hatching rate of 68%, with 35 - 40% of the resulting larvae developing to normal adults. This Success rite in embryos of this age may reflect a reduced sensitivity to limited devitrification or a more even distribution of the ethylene glycol within the embryo.

  9. Sex difference in pathology of the ageing gut mediates the greater response of female lifespan to dietary restriction.

    PubMed

    Regan, Jennifer C; Khericha, Mobina; Dobson, Adam J; Bolukbasi, Ekin; Rattanavirotkul, Nattaphong; Partridge, Linda

    2016-01-01

    Women live on average longer than men but have greater levels of late-life morbidity. We have uncovered a substantial sex difference in the pathology of the aging gut in Drosophila. The intestinal epithelium of the aging female undergoes major deterioration, driven by intestinal stem cell (ISC) division, while lower ISC activity in males associates with delay or absence of pathology, and better barrier function, even at old ages. Males succumb to intestinal challenges to which females are resistant, associated with fewer proliferating ISCs, suggesting a trade-off between highly active repair mechanisms and late-life pathology in females. Dietary restriction reduces gut pathology in aging females, and extends female lifespan more than male. By genetic sex reversal of a specific gut region, we induced female-like aging pathologies in males, associated with decreased lifespan, but also with a greater increase in longevity in response to dietary restriction. PMID:26878754

  10. Age-associated loss of lamin-B leads to systemic inflammation and gut hyperplasia

    PubMed Central

    Chen, Haiyang; Zheng, Xiaobin; Zheng, Yixian

    2014-01-01

    Aging of immune organs, termed as immunosenescence, is suspected to promote systemic inflammation and age-associated disease. The cause of immunosenescence and how it promotes disease, however, has remained unexplored. We report that the Drosophila fat body, a major immune organ, undergoes immunosenescence and mounts strong systemic inflammation that leads to de-regulation of immune deficiency (IMD) signaling in the midgut of old animals. Inflamed old fat bodies secrete circulating peptidoglycan recognition proteins that repress IMD activity in the midgut, thereby promoting gut hyperplasia. Further, fat body immunosenecence is caused by age-associated lamin-B reduction specifically in fat body cells, which then contributes to heterochromatin loss and de-repression of genes involved in immune responses. As lamin-associated heterochromatin domains are enriched for genes involved in immune response in both Drosophila and mammalian cells, our findings may provide insights into the cause and consequence of immunosenescence during aging. PMID:25417159

  11. Gut microbiota and hepatic encephalopathy.

    PubMed

    Dhiman, Radha K

    2013-06-01

    There is a strong relationship between liver and gut; while the portal venous system receives blood from the gut, and its contents may affect liver functions, liver in turn, affects intestinal functions through bile secretion. There is robust evidence that the pathogenesis of hepatic encephalopathy (HE) is linked to alterations in gut microbiota and their by-products such as ammonia, indoles, oxindoles, endotoxins, etc. In the setting of intestinal barrier and immune dysfunction, these by-products are involved in the pathogenesis of complications of liver cirrhosis including HE and systemic inflammation plays an important role. Prebiotics, probiotics and synbiotics may exhibit efficacy in the treatment of HE by modulating the gut flora. They improve derangement in flora by decreasing the counts of pathogenic bacteria and thus improving the endotoxemia, HE and the liver disease. Current evidence suggest that the trials evaluating the role of probiotics in the treatment of HE are of not high quality and all trials had high risk of bias and high risk of random errors. Therefore, the use of probiotics for patients with HE cannot be currently recommended. Further RCTs are required. This review summarizes the main literature findings about the relationships between gut flora and HE, both in terms of the pathogenesis and the treatment of HE. PMID:23463489

  12. Gut immunity in Lepidopteran insects.

    PubMed

    Wu, Kai; Yang, Bing; Huang, Wuren; Dobens, Leonard; Song, Hongsheng; Ling, Erjun

    2016-11-01

    Lepidopteran insects constitute one of the largest fractions of animals on earth, but are considered pests in their relationship with man. Key to the success of this order of insects is its ability to digest food and absorb nutrition, which takes place in the midgut. Because environmental microorganisms can easily enter Lepidopteran guts during feeding, the innate immune response guards against pathogenic bacteria, virus and microsporidia that can be devoured with food. Gut immune responses are complicated by both resident gut microbiota and the surrounding peritrophic membrane and are distinct from immune responses in the body cavity, which depend on the function of the fat body and hemocytes. Due to their relevance to agricultural production, studies of Lepidopteran insect midgut and immunity are receiving more attention, and here we summarize gut structures and functions, and discuss how these confer immunity against different microorganisms. It is expected that increased knowledge of Lepidopteran gut immunity may be utilized for pest biological control in the future. PMID:26872544

  13. Gut Microbiota and Celiac Disease.

    PubMed

    Marasco, Giovanni; Di Biase, Anna Rita; Schiumerini, Ramona; Eusebi, Leonardo Henry; Iughetti, Lorenzo; Ravaioli, Federico; Scaioli, Eleonora; Colecchia, Antonio; Festi, Davide

    2016-06-01

    Recent evidence regarding celiac disease has increasingly shown the role of innate immunity in triggering the immune response by stimulating the adaptive immune response and by mucosal damage. The interaction between the gut microbiota and the mucosal wall is mediated by the same receptors which can activate innate immunity. Thus, changes in gut microbiota may lead to activation of this inflammatory pathway. This paper is a review of the current knowledge regarding the relationship between celiac disease and gut microbiota. In fact, patients with celiac disease have a reduction in beneficial species and an increase in those potentially pathogenic as compared to healthy subjects. This dysbiosis is reduced, but might still remain, after a gluten-free diet. Thus, gut microbiota could play a significant role in the pathogenesis of celiac disease, as described by studies which link dysbiosis with the inflammatory milieu in celiac patients. The use of probiotics seems to reduce the inflammatory response and restore a normal proportion of beneficial bacteria in the gastrointestinal tract. Additional evidence is needed in order to better understand the role of gut microbiota in the pathogenesis of celiac disease, and the clinical impact and therapeutic use of probiotics in this setting. PMID:26725064

  14. Simple Physics in Diseases and Embryonic Development of the Eye

    NASA Astrophysics Data System (ADS)

    Shirinifard, Abbas

    2011-03-01

    While molecular-level regulation within cells during embryonic development is highly complex, the physical mechanisms which translate this intracellular information into multicellular physical structure at the tissue level are often surprisingly simple. I will discuss an example where regulation of cell-cell contact energies is primarily responsible for robust and evolvable regular patterns, the organization of the ommatidia and supporting cells into the regular tiling characteristic of the Drosophila eye and another example where adhesion failures in the human retina result in choroidal neovascularization leading to blindness. In both cases, simulations based on materials-science techniques can help us understand the patterning mechanisms and the reasons for their robustness and failures. Such simulations are easy to extend to other developmental phenomena and to development-related diseases like cancer. EPA grant ``The Texas-Indiana Virtual STAR Center'' and NIH grants R01 GM76692 and R01 GM077138.

  15. Neuronal control of locomotor handedness in Drosophila

    PubMed Central

    Buchanan, Sean M.; Kain, Jamey S.; de Bivort, Benjamin L.

    2015-01-01

    Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are nonheritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality. PMID:25953337

  16. Neuronal control of locomotor handedness in Drosophila.

    PubMed

    Buchanan, Sean M; Kain, Jamey S; de Bivort, Benjamin L

    2015-05-26

    Genetically identical individuals display variability in their physiology, morphology, and behaviors, even when reared in essentially identical environments, but there is little mechanistic understanding of the basis of such variation. Here, we investigated whether Drosophila melanogaster displays individual-to-individual variation in locomotor behaviors. We developed a new high-throughout platform capable of measuring the exploratory behavior of hundreds of individual flies simultaneously. With this approach, we find that, during exploratory walking, individual flies exhibit significant bias in their left vs. right locomotor choices, with some flies being strongly left biased or right biased. This idiosyncrasy was present in all genotypes examined, including wild-derived populations and inbred isogenic laboratory strains. The biases of individual flies persist for their lifetime and are nonheritable: i.e., mating two left-biased individuals does not yield left-biased progeny. This locomotor handedness is uncorrelated with other asymmetries, such as the handedness of gut twisting, leg-length asymmetry, and wing-folding preference. Using transgenics and mutants, we find that the magnitude of locomotor handedness is under the control of columnar neurons within the central complex, a brain region implicated in motor planning and execution. When these neurons are silenced, exploratory laterality increases, with more extreme leftiness and rightiness. This observation intriguingly implies that the brain may be able to dynamically regulate behavioral individuality. PMID:25953337

  17. The Gut Microbiome and Obesity.

    PubMed

    John, George Kunnackal; Mullin, Gerard E

    2016-07-01

    The gut microbiome consists of trillions of bacteria which play an important role in human metabolism. Animal and human studies have implicated distortion of the normal microbial balance in obesity and metabolic syndrome. Bacteria causing weight gain are thought to induce the expression of genes related to lipid and carbohydrate metabolism thereby leading to greater energy harvest from the diet. There is a large body of evidence demonstrating that alteration in the proportion of Bacteroidetes and Firmicutes leads to the development of obesity, but this has been recently challenged. It is likely that the influence of gut microbiome on obesity is much more complex than simply an imbalance in the proportion of these phyla of bacteria. Modulation of the gut microbiome through diet, pre- and probiotics, antibiotics, surgery, and fecal transplantation has the potential to majorly impact the obesity epidemic. PMID:27255389

  18. Natural GUT and the cosmology

    NASA Astrophysics Data System (ADS)

    Maekawa, Nobuhiro

    2012-07-01

    In the natural GUT, not only realistic quark and lepton mass matrices can be obtained but also the most serious problem in the SUSY GUT, which is called the doublet-triplet splitting problem, can be solved under the natural assumption that all the interactions which are allowed by the symmetry are introduced with O(1) coefficients (including the higher dimensional operators). In this manuscript, we examine several cosmological aspects which are related with the natural GUT, B - L-genesis, non-thermal production of dark matter (DM), vacuum selection by particle production, and the inflation after the trapping. These works are based on several papers[1, 2, 3] collaborated with S. Enomoto, S. Iida, Y. Kurata, and T. Matsuda.

  19. Natural GUT and the cosmology

    SciTech Connect

    Maekawa, Nobuhiro

    2012-07-27

    In the natural GUT, not only realistic quark and lepton mass matrices can be obtained but also the most serious problem in the SUSY GUT, which is called the doublet-triplet splitting problem, can be solved under the natural assumption that all the interactions which are allowed by the symmetry are introduced with O(1) coefficients (including the higher dimensional operators). In this manuscript, we examine several cosmological aspects which are related with the natural GUT, B - L-genesis, non-thermal production of dark matter (DM), vacuum selection by particle production, and the inflation after the trapping. These works are based on several papers[1, 2, 3] collaborated with S. Enomoto, S. Iida, Y. Kurata, and T. Matsuda.

  20. Global F-theory GUTs

    SciTech Connect

    Blumenhagen, Ralph; Grimm, Thomas W.; Jurke, Benjamin; Weigand, Timo; /SLAC

    2010-08-26

    We construct global F-theory GUT models on del Pezzo surfaces in compact Calabi-Yau fourfolds realized as complete intersections of two hypersurface constraints. The intersections of the GUT brane and the flavour branes as well as the gauge flux are described by the spectral cover construction. We consider a split S[U(4) x U(1){sub X}] spectral cover, which allows for the phenomenologically relevant Yukawa couplings and GUT breaking to the MSSM via hypercharge flux while preventing dimension-4 proton decay. General expressions for the massless spectrum, consistency conditions and a new method for the computation of curvature-induced tadpoles are presented. We also provide a geometric toolkit for further model searches in the framework of toric geometry. Finally, an explicit global model with three chiral generations and all required Yukawa couplings is defined on a Calabi-Yau fourfold which is fibered over the del Pezzo transition of the Fano threefold P{sup 4}.

  1. Symbiotic lactobacilli stimulate gut epithelial proliferation via Nox-mediated generation of reactive oxygen species

    PubMed Central

    Jones, Rheinallt M; Luo, Liping; Ardita, Courtney S; Richardson, Arena N; Kwon, Young Man; Mercante, Jeffrey W; Alam, Ashfaqul; Gates, Cymone L; Wu, Huixia; Swanson, Phillip A; Lambeth, J David; Denning, Patricia W; Neish, Andrew S

    2013-01-01

    The resident prokaryotic microbiota of the metazoan gut elicits profound effects on the growth and development of the intestine. However, the molecular mechanisms of symbiotic prokaryotic–eukaryotic cross-talk in the gut are largely unknown. It is increasingly recognized that physiologically generated reactive oxygen species (ROS) function as signalling secondary messengers that influence cellular proliferation and differentiation in a variety of biological systems. Here, we report that commensal bacteria, particularly members of the genus Lactobacillus, can stimulate NADPH oxidase 1 (Nox1)-dependent ROS generation and consequent cellular proliferation in intestinal stem cells upon initial ingestion into the murine or Drosophila intestine. Our data identify and highlight a highly conserved mechanism that symbiotic microorganisms utilize in eukaryotic growth and development. Additionally, the work suggests that specific redox-mediated functions may be assigned to specific bacterial taxa and may contribute to the identification of microbes with probiotic potential. PMID:24141879

  2. Preventing Age-Related Decline of Gut Compartmentalization Limits Microbiota Dysbiosis and Extends Lifespan.

    PubMed

    Li, Hongjie; Qi, Yanyan; Jasper, Heinrich

    2016-02-10

    Compartmentalization of the gastrointestinal (GI) tract of metazoans is critical for health. GI compartments contain specific microbiota, and microbiota dysbiosis is associated with intestinal dysfunction. Dysbiosis develops in aging intestines, yet how this relates to changes in GI compartmentalization remains unclear. The Drosophila GI tract is an accessible model to address this question. Here we show that the stomach-like copper cell region (CCR) in the middle midgut controls distribution and composition of the microbiota. We find that chronic activation of JAK/Stat signaling in the aging gut induces a metaplasia of the gastric epithelium, CCR decline, and subsequent commensal dysbiosis and epithelial dysplasia along the GI tract. Accordingly, inhibition of JAK/Stat signaling in the CCR specifically prevents age-related metaplasia, commensal dysbiosis and functional decline in old guts, and extends lifespan. Our results establish a mechanism by which age-related chronic inflammation causes the decline of intestinal compartmentalization and microbiota dysbiosis, limiting lifespan. PMID:26867182

  3. The Drosophila anatomy ontology

    PubMed Central

    2013-01-01

    Background Anatomy ontologies are query-able classifications of anatomical structures. They provide a widely-used means for standardising the annotation of phenotypes and expression in both human-readable and programmatically accessible forms. They are also frequently used to group annotations in biologically meaningful ways. Accurate annotation requires clear textual definitions for terms, ideally accompanied by images. Accurate grouping and fruitful programmatic usage requires high-quality formal definitions that can be used to automate classification and check for errors. The Drosophila anatomy ontology (DAO) consists of over 8000 classes with broad coverage of Drosophila anatomy. It has been used extensively for annotation by a range of resources, but until recently it was poorly formalised and had few textual definitions. Results We have transformed the DAO into an ontology rich in formal and textual definitions in which the majority of classifications are automated and extensive error checking ensures quality. Here we present an overview of the content of the DAO, the patterns used in its formalisation, and the various uses it has been put to. Conclusions As a result of the work described here, the DAO provides a high-quality, queryable reference for the wild-type anatomy of Drosophila melanogaster and a set of terms to annotate data related to that anatomy. Extensive, well referenced textual definitions make it both a reliable and useful reference and ensure accurate use in annotation. Wide use of formal axioms allows a large proportion of classification to be automated and the use of consistency checking to eliminate errors. This increased formalisation has resulted in significant improvements to the completeness and accuracy of classification. The broad use of both formal and informal definitions make further development of the ontology sustainable and scalable. The patterns of formalisation used in the DAO are likely to be useful to developers of other

  4. Sexual circuitry in Drosophila.

    PubMed

    Auer, Thomas O; Benton, Richard

    2016-06-01

    The sexual behavior of Drosophila melanogaster is an outstanding paradigm to understand the molecular and neuronal basis of sophisticated animal actions. We discuss recent advances in our knowledge of the genetic hardwiring of the underlying neuronal circuitry, and how pertinent sensory cues are differentially detected and integrated in the male and female brain. We also consider how experience influences these circuits over short timescales, and the evolution of these pathways over longer timescales to endow species-specific sexual displays and responses. PMID:26851712

  5. Dynamic phages in the swine gut ecosystem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phages are important drivers of ecosystem functions, yet they are often overlooked in gut microbiome studies. Inclusion of phages in gut microbiome analyses is essential to deciphering complex gut ecology under both normal and disturbed conditions. To assess the effect of antibiotics on phage activi...

  6. The gut microbiota, obesity and insulin resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The human gut is densely populated by commensal and symbiotic microbes (the "gut microbiota"), with the majority of the constituent microorganisms being bacteria. Accumulating evidence indicates that the gut microbiota plays a significant role in the development of obesity, obesity-associated inflam...

  7. Myoblast fusion in Drosophila

    SciTech Connect

    Haralalka, Shruti; Abmayr, Susan M.

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  8. Gut indigenous microbiota and epigenetics

    PubMed Central

    Shenderov, Boris Arkadievich

    2012-01-01

    This review introduces and discusses data regarding fundamental and applied investigations in mammalian epigenomics and gut microbiota received over the last 10 years. Analysis of these data enabled us first to come to the conclusion that the multiple low-molecular-weight substances of indigenous gut microbiota origin should be considered one of the main endogenous factors actively participating in epigenomic mechanisms that are responsible for the mammalian genome reprograming and post-translated modifications. Gut microecological imbalance caused by various biogenic and abiogenic agents and factors can produce different epigenetic abnormalities and the onset and progression of metabolic diseases associated. The authors substantiate the necessity to create an international project ‘Human Gut Microbiota and Epigenomics’ that facilitates interdisciplinary collaborations among scientists and clinicians engaged in host microbial ecology, nutrition, metagenomics, epigenomics, and metabolomics investigations as well as in disease prevention and treatment. Some priority scientific and applied directions in the current omic technologies coupled with gnotobiological approaches are suggested that can open a new era in characterizing the role of the symbiotic microbiota small metabolic and signal molecules in the host epigenomics. Although the discussed subject is only at an early stage its validation can open novel approaches in drug discovery studies. PMID:23990811

  9. [Current view on gut microbiota].

    PubMed

    Bourlioux, P

    2014-01-01

    Gut microbiota is more and more important since metagenomic research have brought new knowledge on this topic especially for human health. Firstly, gut microbiota is a key element for our organism he lives in symbiosis with. Secondly, it interacts favorably with many physiological functions of our organism. Thirdly, at the opposite, it can be an active participant in intestinal pathologies linked to a dysbiosis mainly in chronic inflammatory bowel diseases like Crohn disease or ulcerative colitis but also in obesity, metabolic syndrome, and more prudently in autism and behavioral disorders. In order to keep a good health, it is essential to protect our gut microbiota as soon as our young age and maintain it healthy. Face to a more and more important number of publications for treating certain digestive diseases with fecal microbial transplantation, it needs to be very careful and recommend further studies in order to assess risks and define standardized protocols. Gut microbiota metabolic capacities towards xenobiotics need to be developed, and we must take an interest in the modifications they induce on medicinal molecules. On the other hand, it is essential to study the potent effects of pesticides and other pollutants on microbiota functions. PMID:24438664

  10. Gut microbiota and related diseases: clinical features.

    PubMed

    Stanghellini, Vincenzo; Barbara, Giovanni; Cremon, Cesare; Cogliandro, Rosanna; Antonucci, Alexandra; Gabusi, Veronica; Frisoni, Chiara; De Giorgio, Roberto; Grasso, Valentina; Serra, Mauro; Corinaldesi, Roberto

    2010-10-01

    Intestinal microbiota is essential for gut homeostasis. Specifically, the microorganisms inhabiting the gut lumen interact with the intestinal immune system, supply key nutrients for the major components of the gut wall, and modulate energy metabolism. Host-microbiome interactions can be either beneficial or deleterious, driving gastrointestinal lymphoid tissue activities and shaping gut wall structures. This overview briefly focuses on the potential role played by abnormalities in gut microbiota and relative responses of the gastrointestinal tract in the determination of important pathological conditions such as the irritable bowel syndrome, inflammatory bowel diseases and colorectal cancer. PMID:20865476

  11. Mechanotransduction in Embryonic Vascular Development

    PubMed Central

    Roman, Beth L.; Pekkan, Kerem

    2015-01-01

    A plethora of biochemical signals provides spatial and temporal cues that carefully orchestrate the complex process of vertebrate embryonic development. The embryonic vasculature develops not only in the context of these biochemical cues, but also in the context of the biomechanical forces imparted by blood flow. In the mature vasculature, different blood flow regimes induce distinct genetic programs, and significant progress has been made toward understanding how these forces are perceived by endothelial cells and transduced into biochemical signals. However, it cannot be assumed that paradigms that govern the mature vasculature are pertinent to the developing embryonic vasculature. The embryonic vasculature can respond to the mechanical forces of blood flow, and these responses are critical in vascular remodeling, certain aspects of sprouting angiogenesis, and maintenance of arterial-venous identity. Here, we review data regarding mechanistic aspects of endothelial cell mechanotransduction, with a focus on the response to shear stress, and elaborate upon the multifarious effects of shear stress on the embryonic vasculature. In addition, we discuss emerging predictive vascular growth models and highlight the prospect of combining signaling pathway information with computational modeling. We assert that correlation of precise measurements of hemodynamic parameters with effects on endothelial cell gene expression and cell behavior is required for fully understanding how blood flow-induced loading governs normal vascular development and shapes congenital cardiovascular abnormalities. PMID:22744845

  12. Review: Thermal preference in Drosophila

    PubMed Central

    Dillon, Michael E.; Wang, George; Garrity, Paul A.; Huey, Raymond B.

    2009-01-01

    Environmental temperature strongly affects physiology of ectotherms. Small ectotherms, like Drosophila, cannot endogenously regulate body temperature so must rely on behavior to maintain body temperature within a physiologically permissive range. Here we review what is known about Drosophila thermal preference. Work on thermal behavior in this group is particularly exciting because it provides the opportunity to connect genes to neuromolecular mechanisms to behavior to fitness in the wild. PMID:20161211

  13. A subset of neurons controls the permeability of the peritrophic matrix and midgut structure in Drosophila adults.

    PubMed

    Kenmoku, Hiroyuki; Ishikawa, Hiroki; Ote, Manabu; Kuraishi, Takayuki; Kurata, Shoichiro

    2016-08-01

    The metazoan gut performs multiple physiological functions, including digestion and absorption of nutrients, and also serves as a physical and chemical barrier against ingested pathogens and abrasive particles. Maintenance of these functions and structures is partly controlled by the nervous system, yet the precise roles and mechanisms of the neural control of gut integrity remain to be clarified in Drosophila Here, we screened for GAL4 enhancer-trap strains and labeled a specific subsets of neurons, using Kir2.1 to inhibit their activity. We identified an NP3253 line that is susceptible to oral infection by Gram-negative bacteria. The subset of neurons driven by the NP3253 line includes some of the enteric neurons innervating the anterior midgut, and these flies have a disorganized proventricular structure with high permeability of the peritrophic matrix and epithelial barrier. The findings of the present study indicate that neural control is crucial for maintaining the barrier function of the gut, and provide a route for genetic dissection of the complex brain-gut axis in adults of the model organism Drosophila. PMID:27229474

  14. Optogenetics in Drosophila Neuroscience.

    PubMed

    Riemensperger, Thomas; Kittel, Robert J; Fiala, André

    2016-01-01

    Optogenetic techniques enable one to target specific neurons with light-sensitive proteins, e.g., ion channels, ion pumps, or enzymes, and to manipulate their physiological state through illumination. Such artificial interference with selected elements of complex neuronal circuits can help to determine causal relationships between neuronal activity and the effect on the functioning of neuronal circuits controlling animal behavior. The advantages of optogenetics can best be exploited in genetically tractable animals whose nervous systems are, on the one hand, small enough in terms of cell numbers and to a certain degree stereotypically organized, such that distinct and identifiable neurons can be targeted reproducibly. On the other hand, the neuronal circuitry and the behavioral repertoire should be complex enough to enable one to address interesting questions. The fruit fly Drosophila melanogaster is a favorable model organism in this regard. However, the application of optogenetic tools to depolarize or hyperpolarize neurons through light-induced ionic currents has been difficult in adult flies. Only recently, several variants of Channelrhodopsin-2 (ChR2) have been introduced that provide sufficient light sensitivity, expression, and stability to depolarize central brain neurons efficiently in adult Drosophila. Here, we focus on the version currently providing highest photostimulation efficiency, ChR2-XXL. We exemplify the use of this optogenetic tool by applying it to a widely used aversive olfactory learning paradigm. Optogenetic activation of a population of dopamine-releasing neurons mimics the reinforcing properties of a punitive electric shock typically used as an unconditioned stimulus. In temporal coincidence with an odor stimulus this artificially induced neuronal activity causes learning of the odor signal, thereby creating a light-induced memory. PMID:26965122

  15. Gut microbiome, gut function, and probiotics: Implications for health.

    PubMed

    Hajela, Neerja; Ramakrishna, B S; Nair, G Balakrish; Abraham, Philip; Gopalan, Sarath; Ganguly, Nirmal K

    2015-03-01

    New insights from a rapidly developing field of research have ushered in a new era of understanding of the complexity of host-microbe interactions within the human body. The paradigm shift from culturing to metagenomics has provided an insight into the complex diversity of the microbial species that we harbor, revealing the fact that we are in fact more microbes than human cells. The largest consortium of these microbes resides in the gut and is called the gut microbiota. This new science has expanded the ability to document shifts in microbial populations to an unparalleled degree. It is now understood that signals from the microbiota provide trophic, nutritional, metabolic, and protective effects for the development and maintenance of the host digestive, immune, and neuroendocrine system. Evidence linking changes in the gut microbiota to gastrointestinal and extraintestinal disorders like irritable bowel syndrome, inflammatory bowel disease, obesity, diabetes, and celiac disease have begun to emerge recently. Probiotics act through diverse mechanisms positively affecting the composition and/or function of the commensal microbiota and alter host immunological responses. Well-controlled intervention trials, systematic reviews, and meta-analysis provide convincing evidence for the benefit of probiotics in prevention and treatment of gastrointestinal as well as extraintestinal disorders. PMID:25917520

  16. Host Genetic Control of the Microbiota Mediates the Drosophila Nutritional Phenotype.

    PubMed

    Chaston, John M; Dobson, Adam J; Newell, Peter D; Douglas, Angela E

    2016-01-01

    A wealth of studies has demonstrated that resident microorganisms (microbiota) influence the pattern of nutrient allocation to animal protein and energy stores, but it is unclear how the effects of the microbiota interact with other determinants of animal nutrition, including animal genetic factors and diet. Here, we demonstrate that members of the gut microbiota in Drosophila melanogaster mediate the effect of certain animal genetic determinants on an important nutritional trait, triglyceride (lipid) content. Parallel analysis of the taxonomic composition of the associated bacterial community and host nutritional indices (glucose, glycogen, triglyceride, and protein contents) in multiple Drosophila genotypes revealed significant associations between the abundance of certain microbial taxa, especially Acetobacteraceae and Xanthamonadaceae, and host nutritional phenotype. By a genome-wide association study of Drosophila lines colonized with a defined microbiota, multiple host genes were statistically associated with the abundance of one bacterium, Acetobacter tropicalis. Experiments using mutant Drosophila validated the genetic association evidence and reveal that host genetic control of microbiota abundance affects the nutritional status of the flies. These data indicate that the abundance of the resident microbiota is influenced by host genotype, with consequent effects on nutrient allocation patterns, demonstrating that host genetic control of the microbiome contributes to the genotype-phenotype relationship of the animal host. PMID:26567306

  17. Host Genetic Control of the Microbiota Mediates the Drosophila Nutritional Phenotype

    PubMed Central

    Chaston, John M.; Dobson, Adam J.; Newell, Peter D.

    2015-01-01

    A wealth of studies has demonstrated that resident microorganisms (microbiota) influence the pattern of nutrient allocation to animal protein and energy stores, but it is unclear how the effects of the microbiota interact with other determinants of animal nutrition, including animal genetic factors and diet. Here, we demonstrate that members of the gut microbiota in Drosophila melanogaster mediate the effect of certain animal genetic determinants on an important nutritional trait, triglyceride (lipid) content. Parallel analysis of the taxonomic composition of the associated bacterial community and host nutritional indices (glucose, glycogen, triglyceride, and protein contents) in multiple Drosophila genotypes revealed significant associations between the abundance of certain microbial taxa, especially Acetobacteraceae and Xanthamonadaceae, and host nutritional phenotype. By a genome-wide association study of Drosophila lines colonized with a defined microbiota, multiple host genes were statistically associated with the abundance of one bacterium, Acetobacter tropicalis. Experiments using mutant Drosophila validated the genetic association evidence and reveal that host genetic control of microbiota abundance affects the nutritional status of the flies. These data indicate that the abundance of the resident microbiota is influenced by host genotype, with consequent effects on nutrient allocation patterns, demonstrating that host genetic control of the microbiome contributes to the genotype-phenotype relationship of the animal host. PMID:26567306

  18. Identification and characterization of kraken, a gene encoding a putative hydrolytic enzyme in Drosophila melanogaster.

    PubMed

    Edwin Chan, H Y; Harris, S J; O'Kane, C J

    1998-11-19

    Kraken, a novel Drosophila gene isolated from a 4-8-h-old Drosophila embryo cDNA library, shows homology to a family of serine hydrolases whose common feature is that they all catalyse breakage of substrates with a carbonyl-containing group. It is a single-copy gene with at least two introns and maps to position 21D on polytene chromosomes. kraken is a member of a conserved gene family. Messenger RNA of kraken is expressed ubiquitously in early embryogenesis. Later, it is concentrated in the foregut and the posterior midgut primordium. Towards the end of embryogenesis, expression of kraken is confined to the gastric caeca. During the third-instar larval stage, kraken is expressed at low levels in the gastric caeca and parts of the gut, and at higher levels in the fat body. We suggest a role for Kraken in detoxification and digestion during embryogenesis and larval development. PMID:9831651

  19. Variation in the Susceptibility of Drosophila to Different Entomopathogenic Nematodes

    PubMed Central

    Peña, Jennifer M.; Carrillo, Mayra A.

    2015-01-01

    Entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema are lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species of Drosophila fruit flies as model hosts. We show that the EPN Steinernema carpocapsae, which is widely used for insect control, is capable of infecting and killing D. melanogaster larvae. S. carpocapsae is associated with the bacterium Xenorhabdus nematophila, and we show that X. nematophila induces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence toward D. melanogaster and that Drosophila species vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection. PMID:25561714

  20. Identification of secreted and cytosolic gelsolin in Drosophila.

    PubMed

    Stella, M C; Schauerte, H; Straub, K L; Leptin, M

    1994-05-01

    We have cloned the gene for Drosophila gelsolin. Two mRNAs are produced from this gene by differential splicing. The protein encoded by the longer mRNA has a signal peptide and its electrophoretic mobility when translated in vitro in the presence of microsomes is higher than when it is translated without microsomes. The protein translated from the shorter mRNA does not show this difference. This indicates that Drosophila like vertebrates has two forms of gelsolin, one secreted, the other cytoplasmic. The mRNA for both is present ubiquitously in the early embryo. Later, the cytoplasmic form is expressed in parts of the gut. The RNA for the secreted form is expressed in the fat body, and the secreted protein is abundant in extracellular fluid (hemolymph). The cytoplasmic form of gelsolin co-localizes with F-actin in the cortex of the cells in the embryo and in larval epithelia. However, during cellularization of the blastoderm it is reduced at the base of the cleavage furrow, a structure similar to the contractile ring in dividing cells. PMID:8175883

  1. Role of Homothorax in region specific regulation of Deformed in embryonic neuroblasts

    PubMed Central

    Kumar, Raviranjan; Chotaliya, Maheshvari; Vuppala, Sruthakeerthi; Auradkar, Ankush; Palasamudrum, Kalyani; Joshi, Rohit

    2015-01-01

    The expression and regulation of Hox genes in developing central nervous system (CNS) lack important details like specific cell types where Hox genes are expressed and the transcriptional regulatory players involved in these cells. In this study we have investigated the expression and regulation of Drosophila Hox gene Deformed (Dfd) in specific cell types of embryonic CNS. Using Dfd neural autoregulatory enhancer we find that Dfd autoregulates itself in cells of mandibular neuromere. We have also investigated the role of a Hox cofactor Homothorax (Hth) for its role in regulating Dfd expression in CNS. We find that Hth exhibits a region specific role in controlling the expression of Dfd, but has no direct role in mandibular Dfd neural autoregulatory circuit. Our results also suggest that homeodomain of Hth is not required for regulating Dfd expression in embryonic CNS. PMID:26409112

  2. GUT implications from neutrino mass

    SciTech Connect

    Carl H. Albright

    2001-06-26

    An overview is given of the experimental neutrino mixing results and types of neutrino models proposed, with special attention to the general features of various GUT models involving intra-family symmetries and horizontal flavor symmetries. Many of the features are then illustrated by a specific SO (10) SUSY GUT model formulated by S.M. Barr and the author which can explain all four types of solar neutrino mixing solutions by various choices of the right-handed Majorana mass matrix. The quantitative nature of the model's large mixing angle solution is used to compare the reaches of a neutrino super beam and a neutrino factory for determining the small U{sub e3} mixing matrix element.

  3. Arabinoxylans, gut microbiota and immunity.

    PubMed

    Mendis, Mihiri; Leclerc, Estelle; Simsek, Senay

    2016-03-30

    Arabinoxylan (AX) is a non-starch polysaccharide found in many cereal grains and is considered as a dietary fiber. Despite their general structure, there is structural heterogeneity among AX originating from different botanical sources. Furthermore, the extraction procedure and hydrolysis by xylolytic enzymes can further render differences to theses AX. The aim of this review was to address the effects of AX on the gut bacteria and their immunomodulatory properties. Given the complex structure of AX, we also aimed to discuss how the structural heterogeneity of AX affects its role in bacterial growth and immunomodulation. The existing literature indicates the role of fine structural details of AX on its potential as polysaccharides that can impact the gut associated microbial growth and immune system. PMID:26794959

  4. Lineage mapping identifies molecular and architectural similarities between the larval and adult Drosophila central nervous system

    PubMed Central

    Lacin, Haluk; Truman, James W

    2016-01-01

    Neurogenesis in Drosophila occurs in two phases, embryonic and post-embryonic, in which the same set of neuroblasts give rise to the distinct larval and adult nervous systems, respectively. Here, we identified the embryonic neuroblast origin of the adult neuronal lineages in the ventral nervous system via lineage-specific GAL4 lines and molecular markers. Our lineage mapping revealed that neurons born late in the embryonic phase show axonal morphology and transcription factor profiles that are similar to the neurons born post-embryonically from the same neuroblast. Moreover, we identified three thorax-specific neuroblasts not previously characterized and show that HOX genes confine them to the thoracic segments. Two of these, NB2-3 and NB3-4, generate leg motor neurons. The other neuroblast is novel and appears to have arisen recently during insect evolution. Our findings provide a comprehensive view of neurogenesis and show how proliferation of individual neuroblasts is dictated by temporal and spatial cues. DOI: http://dx.doi.org/10.7554/eLife.13399.001 PMID:26975248

  5. Differential expression of two scribble isoforms during Drosophila embryogenesis.

    PubMed

    Li, M; Marhold, J; Gatos, A; Török, I; Mechler, B M

    2001-10-01

    The tumour suppressor gene scribble (scrib) is required for epithelial polarity and growth control in Drosophila. Here, we report the identification and embryonic expression pattern of two Scrib protein isoforms resulting from alternative splicing during scrib transcription. Both proteins are first ubiquitously expressed during early embryogenesis. Then, during morphogenesis each Scrib protein displays a specific pattern of expression in the central and peripheral nervous systems, CNS and PNS, respectively. During germ band extension, the expression of the longer form Scrib1 occurs predominantly in the neuroblasts derived from the neuro-ectoderm and becomes later restricted to CNS neurones as well as to the pole cells in the gonads. By contrast, the shorter form Scrib2 is strongly expressed in the PNS and a subset of CNS neurones. PMID:11578873

  6. Ontogeny of Drosophila melanogaster in a system of dysgenic crosses

    SciTech Connect

    Grishaeva, T.M.; Ivashchenko, N.I.

    1995-09-01

    Three families of mobile elements that induce P-M, H-E, and I-R hybrid dysgenesis in Drosophila melanogaster were activated by crossing flies of different cytotypes. Manifestation of gonadal sterility in F{sub 1} hybrid progeny was dependent on the temperature of development. The systems differed significantly in lethality of F{sub 2} hybrids at various stages of ontogeny (embyros, larvae, pupae, and adult flies). The highest embryo lethality was found in the P-M system at the cleavage stage. In the I-R and H-E systems, the peak of embryonic death corresponded to the stages of blastoderm and organogenesis, respectively. Experimental results are discussed in view of molecular and cytological characteristics of interacting strains and existing hypotheses for regulation of transposition of P, hobo, and I mobile elements. 44 refs., 4 figs., 4 tabs.

  7. Embryonic and larval development of Brycon amazonicus (SPIX & AGASSIZ, 1829).

    PubMed

    Nakauth, A C S Sampaio; Villacorta-Correa, M A; Figueiredo, M R; Bernardino, G; França, J M

    2016-02-01

    The objective of this study was to describe the embryonic and larval development of Brycon amazonicus, featuring the main events up to 50 hours after fertilization (AF). The material was provided by the Aquaculture Training, Technology and Production Center, Presidente Figueiredo (AM). The characterization was based on stereomicroscopic examination of the morphology of eggs, embryos and larvae and comparison with the literature. Matrinxã eggs are free, transparent, and spherical, with a perivitelline space of 0.56 ± 0.3 mm. The successive divisions give rise to cells with 64 blastomeres during the first hour AF. The gastrula stage, beginning 02 h 40 min AF, was characterized by progressive regression cells and the formation of the embryonic axis, leading to differentiation of the head and tail 05 h 30 min AF. From 06 to 09 h AF the somites, notochord, otic and optic vesicles and otoliths were observed, in addition to heart rate and the release of the tail. The larvae hatched at 10 h 30 min AF (29.9 °C), with a total length of 3.56 ± 0.46 mm. Between 19 and 30 h AF, we observed 1) pigmentation and gut formation, 2) branchial arches, 3) pectoral fins, 4) a mouth opening and 5) teeth. Cannibalism was initiated earlier (34 h AF) which was associated with rapid yolk absorption (more than 90% until 50 h AF), signaling the need for an exogenous nutritional source. The environmental conditions (especially temperature) influenced the time course of some events throughout the embryonic and larval development, suggesting the need for further studies on this subject. PMID:26909629

  8. Cospeciation of gut microbiota with hominids.

    PubMed

    Moeller, Andrew H; Caro-Quintero, Alejandro; Mjungu, Deus; Georgiev, Alexander V; Lonsdorf, Elizabeth V; Muller, Martin N; Pusey, Anne E; Peeters, Martine; Hahn, Beatrice H; Ochman, Howard

    2016-07-22

    The evolutionary origins of the bacterial lineages that populate the human gut are unknown. Here we show that multiple lineages of the predominant bacterial taxa in the gut arose via cospeciation with humans, chimpanzees, bonobos, and gorillas over the past 15 million years. Analyses of strain-level bacterial diversity within hominid gut microbiomes revealed that clades of Bacteroidaceae and Bifidobacteriaceae have been maintained exclusively within host lineages across hundreds of thousands of host generations. Divergence times of these cospeciating gut bacteria are congruent with those of hominids, indicating that nuclear, mitochondrial, and gut bacterial genomes diversified in concert during hominid evolution. This study identifies human gut bacteria descended from ancient symbionts that speciated simultaneously with humans and the African apes. PMID:27463672

  9. Requirement of matrix metalloproteinase-1 for intestinal homeostasis in the adult Drosophila midgut

    SciTech Connect

    Lee, Shin-Hae; Park, Joung-Sun; Kim, Young-Shin; Chung, Hae-Young; Yoo, Mi-Ae

    2012-03-10

    Stem cells are tightly regulated by both intrinsic and extrinsic signals as well as the extracellular matrix (ECM) for tissue homeostasis and regenerative capacity. Matrix metalloproteinases (MMPs), proteolytic enzymes, modulate the turnover of numerous substrates, including cytokine precursors, growth factors, and ECM molecules. However, the roles of MMPs in the regulation of adult stem cells are poorly understood. In the present study, we utilize the Drosophila midgut, which is an excellent model system for studying stem cell biology, to show that Mmp1 is involved in the regulation of intestinal stem cells (ISCs). The results showed that Mmp1 is expressed in the adult midgut and that its expression increases with age and with exposure to oxidative stress. Mmp1 knockdown or Timp-overexpressing flies and flies heterozygous for a viable, hypomorphic Mmp1 allele increased ISC proliferation in the gut, as shown by staining with an anti-phospho-histone H3 antibody and BrdU incorporation assays. Reduced Mmp1 levels induced intestinal hyperplasia, and the Mmp1depletion-induced ISC proliferation was rescued by the suppression of the EGFR signaling pathway, suggesting that Mmp1 regulates ISC proliferation through the EGFR signaling pathway. Furthermore, adult gut-specific knockdown and whole-animal heterozygotes of Mmp1 increased additively sensitivity to paraquat-induced oxidative stress and shortened lifespan. Our data suggest that Drosophila Mmp1 is involved in the regulation of ISC proliferation for maintenance of gut homeostasis. -- Highlights: Black-Right-Pointing-Pointer Mmp1 is expressed in the adult midgut. Black-Right-Pointing-Pointer Mmp1 is involved in the regulation of ISC proliferation activity. Black-Right-Pointing-Pointer Mmp1-related ISC proliferation is associated with EGFR signaling. Black-Right-Pointing-Pointer Mmp1 in the gut is required for the intestinal homeostasis and longevity.

  10. The GOCE User Toolbox (GUT) and Tutorial

    NASA Astrophysics Data System (ADS)

    Bingham, R. J.; Benveniste, J.; Knudsen, P.

    2015-12-01

    The GOCE User Toolbox (GUT) is an integrated suite of tools for the analysis and use of GOCE Level 2 gravity products. GUT supports applications in geodesy, oceanography and solid earth physics. The accompanying GUT tutorial provides information and guidance on how to use the toolbox for a variety of applications within each of these domains. An important motivation for the development of GUT has been the desire that users should be able to exploit the GOCE gravity products to calculate derived products relevant to their particular domains without necessarily needing to understand the technicalities of particular geodetic concepts and algorithms. As such, GUT is also suitable for use as an aid to the teaching of geophysics. A comprehensive and up-to-date set of a-priori data and models are supplied with the toolbox, together with a range of pre-defined workflows, allowing the user to immediately calculate useful geophysical quantities. The toolbox is supported by The GUT Algorithm Description and User Guide and The GUT Install Guide. GUT is cross-platform and may be used on Windows PCs, UNIX/Linux workstations and Macs. GUT version 2.2 was released in April 2014 and, besides some bug-fixes, the capability to calculate the simple Bouguer anomaly was added. Recently, GUT version 3 has been released. Through a collaborative effort between the relevant scientific communities, this version has built on earlier releases by further extending the functionality of the toolbox within the fields of geodesy, oceanography and solid earth physics. Additions include the ability to work directly with gravity gradients, anisotropic diffusive filtering, and the computation of Bouguer and isostatic gravity anomalies. The interface between the user and the toolbox has also been greatly improved and GUT version 3 now includes an attractive and intuitive Graphical User Interface. An associated GUT VCM tool for analysing the GOCE variance covariance matrices is also available.

  11. Drosophila as a model for the two myeloid blood cell systems in vertebrates

    PubMed Central

    Gold, Katrina S.; Brückner, Katja

    2016-01-01

    Fish, mice and men rely on two coexisting myeloid blood cell systems. One is sustained by hematopoietic progenitor cells, which reside in specialized microenvironments in hematopoietic organs and give rise to cells of the monocyte lineage. The other system corresponds to the independent lineage of self-renewing tissue macrophages, which colonize organs during embryonic development and are maintained during later life by proliferation in local tissue microenvironments. However, little is known about the nature of these microenvironments and their regulation. Moreover, many vertebrate tissues contain a mix of both tissue-resident and monocyte-derived macrophages, posing a challenge to the study of lineage-specific regulatory mechanisms and function. This review highlights how research in the simple model organism Drosophila melanogaster can address many of these outstanding questions in the field. Drawing parallels between hematopoiesis in Drosophila and vertebrates, we illustrate the evolutionary conservation of the two myeloid systems across animal phyla. Much like vertebrates, Drosophila possesses a lineage of self-renewing tissue-resident macrophages, as well as a ‘definitive’ lineage of macrophages that derive from hematopoiesis in the progenitor-based lymph gland. We summarize key findings from Drosophila hematopoiesis that illustrate how local microenvironments, systemic signals, immune challenges and nervous inputs regulate adaptive responses of tissue-resident macrophages and progenitor-based hematopoiesis to achieve optimal fitness of the animal. PMID:24946019

  12. Purification of Drosophila snRNPs and characterization of two populations of functional U1 particles.

    PubMed Central

    Labourier, E; Rio, D C

    2001-01-01

    U1 snRNP is required at an early stage during assembly of the spliceosome, the dynamic ribonucleoprotein (RNP) complex that performs nuclear pre-mRNA splicing. Here, we report the purification of U1 snRNP particles from Drosophila nuclear extracts and the characterization of their biochemical properties, polypeptide contents, and splicing activities. On the basis of their antigenicity, apparent molecular weight, and by peptide sequencing, the Drosophila 70K, SNF, B, U1-C, D1, D2, D3, E, F, and G proteins are shown to be integral components of these particles. Sequence database searches revealed that both the U1-specific and the Sm proteins are extensively conserved between human and Drosophila snRNPs. Furthermore, both species possess a conserved intrinsic U1-associated kinase activity with identical substrate specificity in vitro. Finally, our results demonstrate that a second type of functional U1 particle, completely lacking the U1/U2-specific protein SNF and the associated protein kinase activity, can be isolated from cultured Kc cell or Canton S embryonic nuclear extracts. This work describes the first characterization of a purified Drosophila snRNP particle and reinforces the view that their activity and composition, with the exception of the atypical bifunctional U1-A/U2-B" SNF protein, are highly conserved in metazoans. PMID:11333025

  13. The structure-function relationships in Drosophila neurotactin show that cholinesterasic domains may have adhesive properties.

    PubMed Central

    Darboux, I; Barthalay, Y; Piovant, M; Hipeau-Jacquotte, R

    1996-01-01

    Neurotactin (Nrt), a Drosophila transmembrane glycoprotein which is expressed in neuronal and epithelial tissues during embryonic and larval stages, exhibits heterophilic adhesive properties. The extracellular domain is composed of a catalytically inactive cholinesterase-like domain. A three-dimensional model deduced from the crystal structure of Torpedo acetylcholinesterase (AChE) has been constructed for Nrt and suggests that its extracellular domain is composed of two sub-domains organized around a gorge: an N-terminal region, whose three-dimensional structure is almost identical to that of Torpedo AChE, and a less conserved C-terminal region. By using truncated Nrt molecules and a homotypic cell aggregation assay which involves a soluble ligand activity, it has been possible to show that the adhesive function is localized in the N-terminal region of the extracellular domain comprised between His347 and His482. The C-terminal region of the protein can be removed without impairing Nrt adhesive properties, suggesting that the two sub-domains are structurally independent. Chimeric molecules in which the Nrt cholinesterase-like domain has been replaced by homologous domains from Drosophila AChE, Torpedo AChE or Drosophila glutactin (Glt), share similar adhesive properties. These properties may require the presence of Nrt cytoplasmic and transmembrane domains since authentic Drosophila AChE does not behave as an adhesive molecule when transfected in S2 cells. Images PMID:8890157

  14. Role of the normal gut microbiota

    PubMed Central

    Jandhyala, Sai Manasa; Talukdar, Rupjyoti; Subramanyam, Chivkula; Vuyyuru, Harish; Sasikala, Mitnala; Reddy, D Nageshwar

    2015-01-01

    Relation between the gut microbiota and human health is being increasingly recognised. It is now well established that a healthy gut flora is largely responsible for overall health of the host. The normal human gut microbiota comprises of two major phyla, namely Bacteroidetes and Firmicutes. Though the gut microbiota in an infant appears haphazard, it starts resembling the adult flora by the age of 3 years. Nevertheless, there exist temporal and spatial variations in the microbial distribution from esophagus to the rectum all along the individual’s life span. Developments in genome sequencing technologies and bioinformatics have now enabled scientists to study these microorganisms and their function and microbe-host interactions in an elaborate manner both in health and disease. The normal gut microbiota imparts specific function in host nutrient metabolism, xenobiotic and drug metabolism, maintenance of structural integrity of the gut mucosal barrier, immunomodulation, and protection against pathogens. Several factors play a role in shaping the normal gut microbiota. They include (1) the mode of delivery (vaginal or caesarean); (2) diet during infancy (breast milk or formula feeds) and adulthood (vegan based or meat based); and (3) use of antibiotics or antibiotic like molecules that are derived from the environment or the gut commensal community. A major concern of antibiotic use is the long-term alteration of the normal healthy gut microbiota and horizontal transfer of resistance genes that could result in reservoir of organisms with a multidrug resistant gene pool. PMID:26269668

  15. Role of the normal gut microbiota.

    PubMed

    Jandhyala, Sai Manasa; Talukdar, Rupjyoti; Subramanyam, Chivkula; Vuyyuru, Harish; Sasikala, Mitnala; Nageshwar Reddy, D

    2015-08-01

    Relation between the gut microbiota and human health is being increasingly recognised. It is now well established that a healthy gut flora is largely responsible for overall health of the host. The normal human gut microbiota comprises of two major phyla, namely Bacteroidetes and Firmicutes. Though the gut microbiota in an infant appears haphazard, it starts resembling the adult flora by the age of 3 years. Nevertheless, there exist temporal and spatial variations in the microbial distribution from esophagus to the rectum all along the individual's life span. Developments in genome sequencing technologies and bioinformatics have now enabled scientists to study these microorganisms and their function and microbe-host interactions in an elaborate manner both in health and disease. The normal gut microbiota imparts specific function in host nutrient metabolism, xenobiotic and drug metabolism, maintenance of structural integrity of the gut mucosal barrier, immunomodulation, and protection against pathogens. Several factors play a role in shaping the normal gut microbiota. They include (1) the mode of delivery (vaginal or caesarean); (2) diet during infancy (breast milk or formula feeds) and adulthood (vegan based or meat based); and (3) use of antibiotics or antibiotic like molecules that are derived from the environment or the gut commensal community. A major concern of antibiotic use is the long-term alteration of the normal healthy gut microbiota and horizontal transfer of resistance genes that could result in reservoir of organisms with a multidrug resistant gene pool. PMID:26269668

  16. Gut Microbiota of Nonalcoholic Fatty Liver Disease.

    PubMed

    Abdou, Reham M; Zhu, Lixin; Baker, Robert D; Baker, Susan S

    2016-05-01

    The prevalence of nonalcoholic fatty liver disease has been rapidly increasing worldwide. It has become a leading cause of liver transplantation. Accumulating evidence suggests a significant role for gut microbiota in its development and progression. Here we review the effect of gut microbiota on developing hepatic fatty infiltration and its progression. Current literature supports a possible role for gut microbiota in the development of liver steatosis, inflammation and fibrosis. We also review the literature on possible interventions for NAFLD that target the gut microbiota. PMID:26898658

  17. Gut inflammation and microbiome in spondyloarthritis.

    PubMed

    Kabeerdoss, Jayakanthan; Sandhya, Pulukool; Danda, Debashish

    2016-04-01

    Spondyloarthritis (SpA) is chronic inflammatory disease involving joints and the spine. Bowel inflammation is common in SpA, which may be classified as acute or chronic. Chronic gut inflammation is most common in SpA patients with axial involvement as compared to those presenting with peripheral involvement alone. The pathogenesis of gut inflammation in SpA could be explained by two factors-over-activation of immunological cells and altered gut microbiome. This is exemplified by SpA animal models, namely HLA-B27-expressing transgenic animals and SKG mice models. Immunological mechanisms include homing of activated T cells from gut into synovium, excess pro-inflammatory cytokines secretion by immune cells such as IL-23 and genetic variations in immunological genes. The evidence for role of gut microbiome in SpA is gradually emerging. Recently, metagenomic study of gut microbiome by sequencing of microbial nucleic acids has enabled identification of new microbial taxa and their functions in gut of patients with SpA. In SpA, the gut microbiome could emerge as diagnostic and prognostic marker of disease. Modulation of gut microbiome is slated to have therapeutic potential as well. PMID:26719306

  18. Gut Microbiota and Type 1 Diabetes

    PubMed Central

    Vaarala, Outi

    2012-01-01

    The gut immune system has a key role in the development of autoimmune diabetes, and factors that control the gut immune system are also regulators of beta-cell autoimmunity. Gut microbiota modulate the function of the gut immune system by their effect on the innate immune system, such as the intestinal epithelial cells and dendritic cells, and on the adaptive immune system, in particular intestinal T cells. Due to the immunological link between gut and pancreas, e.g. the shared lymphocyte homing receptors, the immunological changes in the gut are reflected in the pancreas. According to animal studies, changes in gut microbiota alter the development of autoimmune diabetes. This has been demonstrated by antibiotics that induce changes in the gut microbiota. Furthermore, gut-colonizing microbes may modify the incidence of autoimmune diabetes in animal models. Deficient toll-like receptor (TLR) signaling, mediating microbial stimulus in immune cells, prevents autoimmune diabetes, which appears to be dependent on alterations in the intestinal microbiota. Although few studies have been conducted in humans, recent studies suggest that the abundance of Bacteroides and lack of butyrate-producing bacteria in fecal microbiota are associated with beta-cell autoimmunity and type 1 diabetes. It is possible that altered gut microbiota are associated with immunological aberrancies in type 1 diabetes. The changes in gut microbiota could lead to alterations in the gut immune system, such as increased gut permeability, small intestinal inflammation, and impaired tolerance to food antigens, all of which are observed in type 1 diabetes. Poor fitness of gut microbiota could explain why children who develop type 1 diabetes are prone to enterovirus infections, and do not develop tolerance to cow milk antigens. These candidate risk factors of type 1 diabetes may imply an increased risk of type 1 diabetes due to the presence of gut microbiota that do not support health. Despite the complex

  19. Regulation of proboscipedia in Drosophila by homeotic selector genes.

    PubMed Central

    Rusch, D B; Kaufman, T C

    2000-01-01

    The gene proboscipedia (pb) is a member of the Antennapedia complex in Drosophila and is required for the proper specification of the adult mouthparts. In the embryo, pb expression serves no known function despite having an accumulation pattern in the mouthpart anlagen that is conserved across several insect orders. We have identified several of the genes necessary to generate this embryonic pattern of expression. These genes can be roughly split into three categories based on their time of action during development. First, prior to the expression of pb, the gap genes are required to specify the domains where pb may be expressed. Second, the initial expression pattern of pb is controlled by the combined action of the genes Deformed (Dfd), Sex combs reduced (Scr), cap'n'collar (cnc), and teashirt (tsh). Lastly, maintenance of this expression pattern later in development is dependent on the action of a subset of the Polycomb group genes. These interactions are mediated in part through a 500-bp regulatory element in the second intron of pb. We further show that Dfd protein binds in vitro to sequences found in this fragment. This is the first clear demonstration of autonomous positive cross-regulation of one Hox gene by another in Drosophila melanogaster and the binding of Dfd to a cis-acting regulatory element indicates that this control might be direct. PMID:10978284

  20. Specificity of Rel-inhibitor interactions in Drosophila embryos.

    PubMed Central

    Tatei, K; Levine, M

    1995-01-01

    The Rel family of transcription factors participate in a diverse array of processes, including acute responses to injury and infection, lymphocyte differentiation, and embryonic patterning. These proteins show homology in an extended region spanning about 300 amino acids (the Rel homology domain [RHD]). The RHD mediates both DNA binding and interactions with a family of inhibitor proteins, including I kappa B alpha and cactus. Previous studies have shown that an N-terminal region of the RHD (containing the sequence motif RXXRXRXXC) is important for DNA binding, while the C-terminal nuclear localization sequence is important for inhibitor interactions. Here we present a structure-function analysis of the Drosophila dorsal RHD. These studies identify another sequence within the RHD (region I) that is essential for inhibitor interactions. There is a tight correlation between the conservation of region I sequences and the specificity of Rel-inhibitor interactions in both flies and mammals. Point mutations in the region I sequence can uncouple DNA binding and inhibitor interactions in vitro. The phenotypes associated with the expression of a modified dorsal protein in transgenic Drosophila embryos suggest a similar uncoupling in vivo. Recent crystallographic studies suggest that the region I sequence and the nuclear localization sequence might form a composite surface which interacts with inhibitor proteins. PMID:7791770

  1. Dissection and Immunostaining of Imaginal Discs from Drosophila melanogaster

    PubMed Central

    Spratford, Carrie M.; Kumar, Justin P.

    2014-01-01

    A significant portion of post-embryonic development in the fruit fly, Drosophila melanogaster, takes place within a set of sac-like structures called imaginal discs. These discs give rise to a high percentage of adult structures that are found within the adult fly. Here we describe a protocol that has been optimized to recover these discs and prepare them for analysis with antibodies, transcriptional reporters and protein traps. This procedure is best suited for thin tissues like imaginal discs, but can be easily modified for use with thicker tissues such as the larval brain and adult ovary. The written protocol and accompanying video will guide the reader/viewer through the dissection of third instar larvae, fixation of tissue, and treatment of imaginal discs with antibodies. The protocol can be used to dissect imaginal discs from younger first and second instar larvae as well. The advantage of this protocol is that it is relatively short and it has been optimized for the high quality preservation of the dissected tissue. Another advantage is that the fixation procedure that is employed works well with the overwhelming number of antibodies that recognize Drosophila proteins. In our experience, there is a very small number of sensitive antibodies that do not work well with this procedure. In these situations, the remedy appears to be to use an alternate fixation cocktail while continuing to follow the guidelines that we have set forth for the dissection steps and antibody incubations. PMID:25285379

  2. The role of gut peptides in the gut-brain-axis of livestock

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gut peptides are small hormones produced within the gut that are involved in many biological processes including, but not limited to, appetite regulation, mucosal growth, and metabolism regulation. Some peptides, such as cholecystokinin (CCK) and xenin-25 may affect appetite by altering gut motilit...

  3. Cardiac responses to hypoxia and reoxygenation in Drosophila.

    PubMed

    Zarndt, Rachel; Piloto, Sarah; Powell, Frank L; Haddad, Gabriel G; Bodmer, Rolf; Ocorr, Karen

    2015-12-01

    An adequate supply of oxygen is important for the survival of all tissues, but it is especially critical for tissues with high-energy demands, such as the heart. Insufficient tissue oxygenation occurs under a variety of conditions, including high altitude, embryonic and fetal development, inflammation, and thrombotic diseases, often affecting multiple organ systems. Responses and adaptations of the heart to hypoxia are of particular relevance in human cardiovascular and pulmonary diseases, in which the effects of hypoxic exposure can range in severity from transient to long-lasting. This study uses the genetic model system Drosophila to investigate cardiac responses to acute (30 min), sustained (18 h), and chronic (3 wk) hypoxia with reoxygenation. Whereas hearts from wild-type flies recovered quickly after acute hypoxia, exposure to sustained or chronic hypoxia significantly compromised heart function upon reoxygenation. Hearts from flies with mutations in sima, the Drosophila homolog of the hypoxia-inducible factor alpha subunit (HIF-α), exhibited exaggerated reductions in cardiac output in response to hypoxia. Heart function in hypoxia-selected flies, selected over many generations for survival in a low-oxygen environment, revealed reduced cardiac output in terms of decreased heart rate and fractional shortening compared with their normoxia controls. Hypoxia-selected flies also had smaller hearts, myofibrillar disorganization, and increased extracellular collagen deposition, consistent with the observed reductions in contractility. This study indicates that longer-duration hypoxic insults exert deleterious effects on heart function that are mediated, in part, by sima and advances Drosophila models for the genetic analysis of cardiac-specific responses to hypoxia and reoxygenation. PMID:26377557

  4. The effect of space environment on the development and aging of Drosophila Melanogaster (7-IML-1)

    NASA Technical Reports Server (NTRS)

    Marco, Roberto

    1992-01-01

    This experiment involves the study of the development of eggs of the fly, Drosophila, exposed to microgravity. It is presumed that oogenesis, rather than further states of embryonic development, is sensitive to gravity. This hypothesis will be tested by collecting eggs layered at specific times inflight and postflight from flies exposed to 0 and 1 g. This portion of the experiment is a repetition of an earlier experiment flown in Biorack during the Spacelab D1 Mission. An added feature of the experiment for the First International Microgravity Laboratory (IML-1) Mission is to study the effect of microgravity on the life span of Drosophila male flies. Various aspects of the investigation are discussed.

  5. Why Drosophila to Study Phototransduction?

    PubMed Central

    Pak, William L.

    2010-01-01

    This review recounts the early history of Drosophila phototransduction genetics, covering the period between approximately 1966 to 1979. Early in this period, the author felt that there was an urgent need for a new approach in phototransduction research. Through inputs from a number of colleagues, he was led to consider isolating Drosophila mutants that are defective in the electroretinogram. Thanks to the efforts of dedicated associates and technical staff, by the end of this period, he was able to accumulate a large number of such mutants. Particularly important in this effort was the use of the mutant assay protocol based on the “prolonged depolarizing afterpotential.” This collection of mutants formed the basis of the subsequent intensive investigations of the Drosophila phototransduction cascade by many investigators. PMID:20536286

  6. Micromechanics of Drosophila Audition

    NASA Astrophysics Data System (ADS)

    Göpfert, M. C.; Robert, D.

    2003-02-01

    An analysis is presented of the auditory micromechanics of the fruit fly Drosophila melanogaster. In this animal, the distal part of the antenna constitutes a resonantly tuned sound receiver, the vibrations of which are transduced by a chordotonal sense organ in the antenna's base. Analyzing the mechanical behavior of the antennal receiver by means of microscanning laser Doppler vibrometry, we show that the auditory system of wild-type flies exhibits a hardening stiffness nonlinearity and spontaneously generates oscillations in the absence of external stimuli. According to the deprivation of these mechanical properties in mechanosensory mutants, the receiver's nonlinearity and oscillation activity are introduced by chordotonal auditory neurons. Requiring the mechanoreceptor-specific extracellular linker protein No-mechanoreceptor-potential-A (NompA), NompC mechanosensory transduction channels, Beethoven (Btv), and Touch-insensitive-larva-B (TilB), nonlinearity and oscillation activity of the fly's antennal receiver depend on prominent components of the auditory transduction machinery and seem to originate from motility of auditory receptor cilia.

  7. BEST: a novel computational approach for comparing gene expression patterns from early stages of Drosophila melanogaster development.

    PubMed Central

    Kumar, Sudhir; Jayaraman, Karthik; Panchanathan, Sethuraman; Gurunathan, Rajalakshmi; Marti-Subirana, Ana; Newfeld, Stuart J

    2002-01-01

    Embryonic gene expression patterns are an indispensable part of modern developmental biology. Currently, investigators must visually inspect numerous images containing embryonic expression patterns to identify spatially similar patterns for inferring potential genetic interactions. The lack of a computational approach to identify pattern similarities is an impediment to advancement in developmental biology research because of the rapidly increasing amount of available embryonic gene expression data. Therefore, we have developed computational approaches to automate the comparison of gene expression patterns contained in images of early stage Drosophila melanogaster embryos (prior to the beginning of germ-band elongation); similarities and differences in gene expression patterns in these early stages have extensive developmental effects. Here we describe a basic expression search tool (BEST) to retrieve best matching expression patterns for a given query expression pattern and a computational device for gene interaction inference using gene expression pattern images and information on the associated genotypes and probes. Analysis of a prototype collection of Drosophila gene expression pattern images is presented to demonstrate the utility of these methods in identifying biologically meaningful matches and inferring gene interactions by direct image content analysis. In particular, the use of BEST searches for gene expression patterns is akin to that of BLAST searches for finding similar sequences. These computational developmental biology methodologies are likely to make the great wealth of embryonic gene expression pattern data easily accessible and to accelerate the discovery of developmental networks. PMID:12524369

  8. Crosslinking of a Peritrophic Matrix Protein Protects Gut Epithelia from Bacterial Exotoxins

    PubMed Central

    Shibata, Toshio; Maki, Kouki; Hadano, Jinki; Fujikawa, Takumi; Kitazaki, Kazuki; Koshiba, Takumi; Kawabata, Shun-ichiro

    2015-01-01

    Transglutaminase (TG) catalyzes protein-protein crosslinking, which has important and diverse roles in vertebrates and invertebrates. Here we demonstrate that Drosophila TG crosslinks drosocrystallin, a peritrophic matrix protein, to form a stable fiber structure on the gut peritrophic matrix. RNA interference (RNAi) of the TG gene was highly lethal in flies and induced apoptosis of gut epithelial cells after oral infection with Pseudomonas entomophila. Moreover, AprA, a metalloprotease secreted by P. entomophila, digested non-crosslinked drosocrystallin fibers, but not drosocrystallin fibers crosslinked by TG. In vitro experiments using recombinant drosocrystallin and monalysin proteins demonstrated that monalysin, a pore-forming exotoxin of P. entomophila, was adsorbed on the crosslinked drosocrystallin fibers in the presence of P. entomophila culture supernatant. In addition, gut-specific TG-RNAi flies had a shorter lifespan than control flies after ingesting P. entomophila, whereas the lifespan after ingesting AprA-knockout P. entomophila was at control levels. We conclude that drosocrystallin fibers crosslinked by TG, but not non-crosslinked drosocrystallin fibers, form an important physical barrier against exotoxins of invading pathogenic microbes. PMID:26506243

  9. Resistance to Innate Immunity Contributes to Colonization of the Insect Gut by Yersinia pestis

    PubMed Central

    Earl, Shaun C.; Rogers, Miles T.; Keen, Jennifer; Bland, David M.; Houppert, Andrew S.; Miller, Caitlynn; Temple, Ian; Anderson, Deborah M.; Marketon, Melanie M.

    2015-01-01

    Yersinia pestis, the causative agent of bubonic and pneumonic plague, is typically a zoonotic vector-borne disease of wild rodents. Bacterial biofilm formation in the proventriculus of the flea contributes to chronic infection of fleas and facilitates efficient disease transmission. However prior to biofilm formation, ingested bacteria must survive within the flea midgut, and yet little is known about vector-pathogen interactions that are required for flea gut colonization. Here we establish a Drosophila melanogaster model system to gain insight into Y. pestis colonization of the insect vector. We show that Y. pestis establishes a stable infection in the anterior midgut of fly larvae, and we used this model system to study the roles of genes involved in biofilm production and/or resistance to gut immunity stressors. We find that PhoP and GmhA both contribute to colonization and resistance to antimicrobial peptides in flies, and furthermore, the data suggest biofilm formation may afford protection against antimicrobial peptides. Production of reactive oxygen species in the fly gut, as in fleas, also serves to limit bacterial infection, and OxyR mediates Y. pestis survival in both insect models. Overall, our data establish the fruit fly as an informative model to elucidate the relationship between Y. pestis and its flea vector. PMID:26177454

  10. The Human Bcl-2 Family Member Bcl-rambo Localizes to Mitochondria and Induces Apoptosis and Morphological Aberrations in Drosophila

    PubMed Central

    Matsushita, Yuka; Watanabe, Megumi; Vo, Nicole; Yoshida, Hideki; Yamaguchi, Masamitsu; Kataoka, Takao

    2016-01-01

    Bcl-2 family proteins play a central role in regulating apoptosis. We previously reported that human Bcl-rambo, also termed BCL2L13, localized to mitochondria and induced apoptosis when overexpressed in human embryonic kidney 293T cells. However, the physiological function of Bcl-rambo currently remains unclear. In the present study, human Bcl-rambo was ectopically expressed in Drosophila melanogaster. Bcl-rambo mainly localized to the mitochondria of Drosophila Schneider 2 (S2) cells. The overexpression of Bcl-rambo, but not Bcl-rambo lacking a C-terminal transmembrane domain, induced apoptosis in S2 cells. Moreover, the ectopic expression of Bcl-rambo by a GAL4-UAS system induced aberrant morphological changes characterized by atrophied wing, split thorax, and rough eye phenotypes. Bcl-rambo induced the activation of effector caspases in eye imaginal discs. The rough eye phenotype induced by Bcl-rambo was partly rescued by the co-expression of p35, Diap1, and Diap2. By using this Drosophila model, we showed that human Bcl-rambo interacted genetically with Drosophila homologues of adenine nucleotide translocators and the autophagy-related 8 protein. The results of the present study demonstrated that human Bcl-rambo localized to mitochondria and at least regulated an apoptosis signaling pathway in Drosophila. PMID:27348811

  11. Embryonic development during chronic acceleration

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Abbott, U. K.

    1982-01-01

    Experiments carried out on chicken eggs indicate that the embryo is affected during very early development, especially over the first four days, and during hatching. In the first four days, the brain develops as well as the anlage for all other organs. In addition, the heart commences to function and the extraembryonic membranes that compartmentalize the egg contents form. The latter require an appreciable extension and folding of tissue which may be disrupted by the mechanical load. Observations of embryonic abnormalities that occur during chronic acceleration suggest an inhibition of development of the axial skeleton, which is rarely seen otherwise, a general retardation of embryonic growth, and circulatory problems. The final stages of development (after 18 days) involve the uptake of fluids, the transition to aerial respiration, and the reorientation of the embryo into a normal hatching position. At 4 G mortality is very high during this period, with a majority of embryos failing to reorient into the normal hatching position.

  12. Embryonic Heart Progenitors and Cardiogenesis

    PubMed Central

    Brade, Thomas; Pane, Luna S.; Moretti, Alessandra; Chien, Kenneth R.; Laugwitz, Karl-Ludwig

    2013-01-01

    The mammalian heart is a highly specialized organ, comprised of many different cell types arising from distinct embryonic progenitor populations during cardiogenesis. Three precursor populations have been identified to contribute to different myocytic and nonmyocytic cell lineages of the heart: cardiogenic mesoderm cells (CMC), the proepicardium (PE), and cardiac neural crest cells (CNCCs). This review will focus on molecular cues necessary for proper induction, expansion, and lineage-specific differentiation of these progenitor populations during cardiac development in vivo. Moreover, we will briefly discuss how the knowledge gained on embryonic heart progenitor biology can be used to develop novel therapeutic strategies for the management of congenital heart disease as well as for improvement of cardiac function in ischemic heart disease. PMID:24086063

  13. Altered gut transcriptome in spondyloarthropathy

    PubMed Central

    Laukens, D; Peeters, H; Cruyssen, B V; Boonefaes, T; Elewaut, D; De Keyser, F; Mielants, H; Cuvelier, C; Veys, E M; Knecht, K; Van Hummelen, P; Remaut, E; Steidler, L; De Vos, M; Rottiers, P

    2006-01-01

    Background Intestinal inflammation is a common feature of spondyloarthropathy (SpA) and Crohn's disease. Inflammation is manifested clinically in Crohn's disease and subclinically in SpA. However, a fraction of patients with SpA develops overt Crohn's disease. Aims To investigate whether subclinical gut lesions in patients with SpA are associated with transcriptome changes comparable to those seen in Crohn's disease and to examine global gene expression in non‐inflamed colon biopsy specimens and screen patients for differentially expressed genes. Methods Macroarray analysis was used as an initial genomewide screen for selecting a comprehensive set of genes relevant to Crohn's disease and SpA. This led to the identification of 2625 expressed sequence tags that are differentially expressed in the colon of patients with Crohn's disease or SpA. These clones, with appropriate controls (6779 in total), were used to construct a glass‐based microarray, which was then used to analyse colon biopsy specimens from 15 patients with SpA, 11 patients with Crohn's disease and 10 controls. Results 95 genes were identified as differentially expressed in patients with SpA having a history of subclinical chronic gut inflammation and also in patients with Crohn's disease. Principal component analysis of this filtered set of genes successfully distinguished colon biopsy specimens from the three groups studied. Patients with SpA having subclinical chronic gut inflammation cluster together and are more related to those with Crohn's disease. Conclusion The transcriptome in the intestine of patients with SpA differs from that of controls. Moreover, these gene changes are comparable to those seen in patients with Crohn's disease, confirming initial clinical observations. On the basis of these findings, new (genetic) markers for detection of early Crohn's disease in patients with SpA can be considered. PMID:16476712

  14. Requirement for Pangolin/dTCF in Drosophila Wingless signaling.

    PubMed

    Schweizer, Liang; Nellen, Denise; Basler, Konrad

    2003-05-13

    The Wingless (Wg) protein is a secreted glycoprotein involved in intercellular signaling. On activation of the Wg signaling pathway, Armadillo is stabilized, causing target genes to be activated by the transcription factor Pangolin (Pan). This study investigated the roles of Pan in the developing wing of Drosophila by clonal analysis. Three different aspects of wing development were examined: cell proliferation, wing margin specification, and wg self-refinement. Our results indicate that Pan function is critically required for all three of these processes. Consequently, lack of pan causes a severe reduction in the activity of the Wg target genes Distalless and vestigial within their normal domain of expression. Loss of pan function does not, however, lead to a derepression of these genes outside this domain. Thus, although Pan is positively required for the induction of Wg targets in the wing imaginal disk, it does not appear to play a default repressor function in the absence of Wg input. In contrast, lack of zygotic pan function causes a milder phenotype than that caused by the lack of wg function in the embryo. We show that this difference cannot be attributed to maternally provided pan product, indicating that a Pan repressor function usually prevents the expression of embryonic Wg targets. Together, our results suggest that for embryonic patterning the activator as well as repressor forms of Pan play important roles, while for wing development Pan operates primarily in the activator mode. PMID:12730381

  15. Maternal AP determinants in the Drosophila oocyte and embryo.

    PubMed

    Ma, Jun; He, Feng; Xie, Gengqiang; Deng, Wu-Min

    2016-09-01

    An animal embryo cannot initiate its journey of forming a new life on its own. It must rely on maternally provided resources and inputs to kick-start its developmental process. In Drosophila, the initial polarities of the embryo along both the anterior-posterior (AP) and dorsal-ventral (DV) axes are also specified by maternal determinants. Over the past several decades, genetic and molecular studies have identified and characterized such determinants, as well as the zygotic genetic regulatory networks that control patterning in the early embryo. Extensive studies of oogenesis have also led to a detailed knowledge of the cellular and molecular interactions that control the formation of a mature egg. Despite these efforts, oogenesis and embryogenesis have been studied largely as separate problems, except for qualitative aspects with regard to maternal regulation of the asymmetric localization of maternal determinants. Can oogenesis and embryogenesis be viewed from a unified perspective at a quantitative level, and can that improve our understanding of how robust embryonic patterning is achieved? Here, we discuss the basic knowledge of the regulatory mechanisms controlling oogenesis and embryonic patterning along the AP axis. We explore properties of the maternal Bicoid gradient in relation to embryo size in search for a unified framework for robust AP patterning. WIREs Dev Biol 2016, 5:562-581. doi: 10.1002/wdev.235 For further resources related to this article, please visit the WIREs website. PMID:27253156

  16. Clostridial disease of the gut.

    PubMed

    Borriello, S P

    1995-06-01

    Clostridia are an important cause of morbidity and mortality in humans and animals. Some of the most common clostridial infections are those of the gut. The primary infections in humans are Clostridium perfringens food poisoning and Clostridium difficile-mediated antibiotic-associated diarrhea and colitis. Less common but important infections include non-food poisoning C. perfringens nosocomial diarrhea and C. perfringens type C necrotizing jejunitis (pig-bel). C. perfringens is also the dominant cause of gastrointestinal infections in animals, although Clostridium septicum causing braxy in sheep, Clostridium colinum causing ulcerative enteritis is avian species, and Clostridium spiroforme causing enterotoxemia in rabbits are important exceptions. PMID:7548565

  17. Gut physiology mediates a trade-off between adaptation to malnutrition and susceptibility to food-borne pathogens.

    PubMed

    Vijendravarma, Roshan K; Narasimha, Sunitha; Chakrabarti, Sveta; Babin, Aurelie; Kolly, Sylvain; Lemaitre, Bruno; Kawecki, Tadeusz J

    2015-10-01

    The animal gut plays a central role in tackling two common ecological challenges, nutrient shortage and food-borne parasites, the former by efficient digestion and nutrient absorption, the latter by acting as an immune organ and a barrier. It remains unknown whether these functions can be independently optimised by evolution, or whether they interfere with each other. We report that Drosophila melanogaster populations adapted during 160 generations of experimental evolution to chronic larval malnutrition became more susceptible to intestinal infection with the opportunistic bacterial pathogen Pseudomonas entomophila. However, they do not show suppressed immune response or higher bacterial loads. Rather, their increased susceptibility to P. entomophila is largely mediated by an elevated predisposition to loss of intestinal barrier integrity upon infection. These results may reflect a trade-off between the efficiency of nutrient extraction from poor food and the protective function of the gut, in particular its tolerance to pathogen-induced damage. PMID:26249109

  18. GUT MICROBIOTA DYSBIOSIS IS LINKED TO HYPERTENSION

    PubMed Central

    Yang, Tao; Santisteban, Monica M.; Rodriguez, Vermali; Li, Eric; Ahmari, Niousha; Carvajal, Jessica Marulanda; Zadeh, Mojgan; Gong, Minghao; Qi, Yanfei; Zubcevic, Jasenka; Sahay, Bikash; Pepine, Carl J.; Raizada, Mohan K.; Mohamadzadeh, Mansour

    2015-01-01

    Emerging evidence suggests that gut microbiota is critical in the maintenance of physiological homeostasis. The present study was designed to test the hypothesis that dysbiosis in gut microbiota is associated with hypertension since genetic, environmental, and dietary factors profoundly influence both gut microbiota and blood pressure. Bacterial DNA from fecal samples of two rat models of hypertension and a small cohort of patients was used for bacterial genomic analysis. We observed a significant decrease in microbial richness, diversity, and evenness in the spontaneously hypertensive rat, in addition to an increased Firmicutes to Bacteroidetes ratio. These changes were accompanied with decreases in acetate- and butyrate-producing bacteria. Additionally, the microbiota of a small cohort of human hypertension patients was found to follow a similar dysbiotic pattern, as it was less rich and diverse than that of control subjects. Similar changes in gut microbiota were observed in the chronic angiotensin II infusion rat model, most notably decreased microbial richness and an increased Firmicutes to Bacteroidetes ratio. In this model, we evaluated the efficacy of oral minocycline in restoring gut microbiota. In addition to attenuating high blood pressure, minocycline was able to rebalance the dysbiotic hypertension gut microbiota by reducing the Firmicutes to Bacteroidetes ratio. These observations demonstrate that high BP is associated with gut microbiota dysbiosis, both in animal and human hypertension. They suggest that dietary intervention to correct gut microbiota could be an innovative nutritional therapeutic strategy for hypertension. PMID:25870193

  19. Gut dysbiosis is linked to hypertension.

    PubMed

    Yang, Tao; Santisteban, Monica M; Rodriguez, Vermali; Li, Eric; Ahmari, Niousha; Carvajal, Jessica Marulanda; Zadeh, Mojgan; Gong, Minghao; Qi, Yanfei; Zubcevic, Jasenka; Sahay, Bikash; Pepine, Carl J; Raizada, Mohan K; Mohamadzadeh, Mansour

    2015-06-01

    Emerging evidence suggests that gut microbiota is critical in the maintenance of physiological homeostasis. This study was designed to test the hypothesis that dysbiosis in gut microbiota is associated with hypertension because genetic, environmental, and dietary factors profoundly influence both gut microbiota and blood pressure. Bacterial DNA from fecal samples of 2 rat models of hypertension and a small cohort of patients was used for bacterial genomic analysis. We observed a significant decrease in microbial richness, diversity, and evenness in the spontaneously hypertensive rat, in addition to an increased Firmicutes/Bacteroidetes ratio. These changes were accompanied by decreases in acetate- and butyrate-producing bacteria. In addition, the microbiota of a small cohort of human hypertensive patients was found to follow a similar dysbiotic pattern, as it was less rich and diverse than that of control subjects. Similar changes in gut microbiota were observed in the chronic angiotensin II infusion rat model, most notably decreased microbial richness and an increased Firmicutes/Bacteroidetes ratio. In this model, we evaluated the efficacy of oral minocycline in restoring gut microbiota. In addition to attenuating high blood pressure, minocycline was able to rebalance the dysbiotic hypertension gut microbiota by reducing the Firmicutes/Bacteroidetes ratio. These observations demonstrate that high blood pressure is associated with gut microbiota dysbiosis, both in animal and human hypertension. They suggest that dietary intervention to correct gut microbiota could be an innovative nutritional therapeutic strategy for hypertension. PMID:25870193

  20. [Gut microbiota: Description, role and pathophysiologic implications].

    PubMed

    Landman, C; Quévrain, E

    2016-06-01

    The human gut contains 10(14) bacteria and many other micro-organisms such as Archaea, viruses and fungi. Studying the gut microbiota showed how this entity participates to gut physiology and beyond this to human health, as a real "hidden organ". In this review, we aimed to bring information about gut microbiota, its structure, its roles and its implication in human pathology. After bacterial colonization in infant, intestinal microbial composition is unique for each individual although more than 95% can be assigned to four major phyla. The use of culture independent methods and more recently the development of high throughput sequencing allowed to depict precisely gut microbiota structure and diversity as well as its alteration in diseases. Gut microbiota is implicated in the maturation of the host immune system and in many fundamental metabolic pathways including sugars and proteins fermentation and metabolism of bile acids and xenobiotics. Imbalance of gut microbial populations or dysbiosis has important functional consequences and is implicated in many digestive diseases (inflammatory bowel diseases, colorectal cancer, etc.) but also in obesity and autism. These observations have led to a surge of studies exploring therapeutics which aims to restore gut microbiota equilibrium such as probiotics or fecal microbiota transplantation. But recent research also investigates biological activity of microbial products which could lead to interesting therapeutics leads. PMID:26749318

  1. Plant phenolics are detoxified by prophenoloxidase in the insect gut.

    PubMed

    Wu, Kai; Zhang, Jie; Zhang, Qiaoli; Zhu, Shoulin; Shao, Qimiao; Clark, Kevin D; Liu, Yining; Ling, Erjun

    2015-01-01

    Plant phenolics are a group of important secondary metabolites that are toxic to many animals and insects if ingested at high concentrations. Because most insects consume plant phenolics daily, they have likely evolved the capacity to detoxify these compounds. Here, we used Drosophila melanogaster, Bombyx mori and Helicoverpa armigera as models to study the metabolism of plant phenolics by prophenoloxidases. We found that insect foreguts release prophenoloxidases into the lumen, and that the survival of prophenoloxidase-deletion mutants was impaired when fed several plant phenolics and tea extracts. Using l-DOPA as a model substrate, biochemical assays in large Lepidopteran insects demonstrated that low levels of l-DOPA are rapidly metabolized into intermediates by phenoloxidases. Feeding with excess l-DOPA showed that the metabolic intermediate 5,6-dihydroxyindole reached the hindgut either by passing directly through the midgut, or by transport through the hemolymph. In the hindgut, 5,6-dihydroxyindole was further oxidized by prophenoloxidases. Intermediates exerted no toxicity in the hemocoel or midgut. These results show that plant phenolics are not toxic to insects unless prophenoloxidase genes are lost or the levels of phenolics exceed the catalytic activity of the gut prophenoloxidases. PMID:26592948

  2. Plant phenolics are detoxified by prophenoloxidase in the insect gut

    PubMed Central

    Wu, Kai; Zhang, Jie; Zhang, Qiaoli; Zhu, Shoulin; Shao, Qimiao; Clark, Kevin D.; Liu, Yining; Ling, Erjun

    2015-01-01

    Plant phenolics are a group of important secondary metabolites that are toxic to many animals and insects if ingested at high concentrations. Because most insects consume plant phenolics daily, they have likely evolved the capacity to detoxify these compounds. Here, we used Drosophila melanogaster, Bombyx mori and Helicoverpa armigera as models to study the metabolism of plant phenolics by prophenoloxidases. We found that insect foreguts release prophenoloxidases into the lumen, and that the survival of prophenoloxidase-deletion mutants was impaired when fed several plant phenolics and tea extracts. Using l-DOPA as a model substrate, biochemical assays in large Lepidopteran insects demonstrated that low levels of l-DOPA are rapidly metabolized into intermediates by phenoloxidases. Feeding with excess l-DOPA showed that the metabolic intermediate 5,6-dihydroxyindole reached the hindgut either by passing directly through the midgut, or by transport through the hemolymph. In the hindgut, 5,6-dihydroxyindole was further oxidized by prophenoloxidases. Intermediates exerted no toxicity in the hemocoel or midgut. These results show that plant phenolics are not toxic to insects unless prophenoloxidase genes are lost or the levels of phenolics exceed the catalytic activity of the gut prophenoloxidases. PMID:26592948

  3. A translational block to HSPG synthesis permits BMP signaling in the early Drosophila embryo

    PubMed Central

    Bornemann, Douglas J.; Park, Sangbin; Phin, Sopheap; Warrior, Rahul

    2010-01-01

    Summary Heparan sulfate proteoglycans (HSPGs) are extracellular macromolecules found on virtually every cell type in eumetazoans. HSPGs are composed of a core protein covalently linked to glycosaminoglycan (GAG) sugar chains that bind and modulate the signaling efficiency of many ligands including Hedgehog (Hh), Wingless (Wg), and Bone Morphogenetic Proteins (BMPs). Here we show that in Drosophila, loss of HSPGs differentially affects embryonic Hh, Wg and BMP signaling. We find that a stage-specific block to GAG synthesis prevents HSPG expression during establishment of the BMP activity gradient that is critical for dorsal embryonic patterning. Subsequently GAG synthesis is initiated coincident with the onset of Hh and Wg signaling which require HSPGs. This temporal regulation is achieved by translational control of HSPG synthetic enzymes through Internal Ribosome Entry Sites (IRES). IRES-like features are conserved in GAG enzyme transcripts from diverse organisms arguing that this represents a novel evolutionarily conserved mechanism for regulating GAG synthesis and modulating growth factor activity. PMID:18256192

  4. atonal regulates neurite arborization but does not act as a proneural gene in the Drosophila brain

    NASA Technical Reports Server (NTRS)

    Hassan, B. A.; Bermingham, N. A.; He, Y.; Sun, Y.; Jan, Y. N.; Zoghbi, H. Y.; Bellen, H. J.

    2000-01-01

    Drosophila atonal (ato) is the proneural gene of the chordotonal organs (CHOs) in the peripheral nervous system (PNS) and the larval and adult photoreceptor organs. Here, we show that ato is expressed at multiple stages during the development of a lineage of central brain neurons that innervate the optic lobes and are required for eclosion. A novel fate mapping approach shows that ato is expressed in the embryonic precursors of these neurons and that its expression is reactivated in third instar larvae (L3). In contrast to its function in the PNS, ato does not act as a proneural gene in the embryonic brain. Instead, ato performs a novel function, regulating arborization during larval and pupal development by interacting with Notch.

  5. Female Sterile Mutations on the Second Chromosome of Drosophila Melanogaster. I. Maternal Effect Mutations

    PubMed Central

    Schupbach, T.; Wieschaus, E.

    1989-01-01

    In mutagenesis screens for recessive female sterile mutations on the second chromosome of Drosophila melanogaster 529 chromosomes were isolated which allow the homozygous females to survive, but cause them to be sterile. In 136 of these lines, mutant females produce morphologically normal eggs which cannot support normal embryonic development. These ``maternal-effect'' mutations fall into 67 complementation groups which define 23 multiply hit and 44 singly hit loci. In eggs from 14 complementation groups development is blocked before the formation of a syncytial blastoderm. In eggs from 12 complementation groups development is abnormal before cellularization, 17 complementation groups cause abnormal cellularization, 12 complementation groups cause changes in cellular morphology in early gastrulation stages, and 12 complementation groups seem to affect later embryonic development. PMID:2492966

  6. Progenitor Outgrowth from the Niche in Drosophila Trachea Is Guided by FGF from Decaying Branches

    PubMed Central

    Chen, Feng; Krasnow, Mark A.

    2014-01-01

    Although there has been progress identifying adult stem and progenitor cells and the signals that control their proliferation and differentiation, little is known about the substrates and signals that guide them out of their niche. By examining Drosophila tracheal outgrowth during metamorphosis, we show that progenitors follow a stereotyped path out of the niche, tracking along a subset of tracheal branches destined for destruction. The embryonic tracheal inducer branchless FGF (fibroblast growth factor) is expressed dynamically just ahead of progenitor outgrowth in decaying branches. Knockdown of branchless abrogates progenitor outgrowth, whereas misexpression redirects it. Thus, reactivation of an embryonic tracheal inducer in decaying branches directs outgrowth of progenitors that replace them. This explains how the structure of a newly generated tissue is coordinated with that of the old. PMID:24408434

  7. The gut microbiome: scourge, sentinel or spectator?

    PubMed Central

    Korecka, Agata; Arulampalam, Velmurugesan

    2012-01-01

    The gut microbiota consists of trillions of prokaryotes that reside in the intestinal mucosa. This long-established commensalism indicates that these microbes are an integral part of the eukaryotic host. Recent research findings have implicated the dynamics of microbial function in setting thresholds for many physiological parameters. Conversely, it has been convincingly argued that dysbiosis, representing microbial imbalance, may be an important underlying factor that contributes to a variety of diseases, inside and outside the gut. This review discusses the latest findings, including enterotype classification, changes brought on by dysbiosis, gut inflammation, and metabolic mediators in an attempt to underscore the importance of the gut microbiota for human health. A cautiously optimistic idea is taking hold, invoking the gut microbiota as a medium to track, target and treat a plethora of diseases. PMID:22368769

  8. A catalog of the mouse gut metagenome.

    PubMed

    Xiao, Liang; Feng, Qiang; Liang, Suisha; Sonne, Si Brask; Xia, Zhongkui; Qiu, Xinmin; Li, Xiaoping; Long, Hua; Zhang, Jianfeng; Zhang, Dongya; Liu, Chuan; Fang, Zhiwei; Chou, Joyce; Glanville, Jacob; Hao, Qin; Kotowska, Dorota; Colding, Camilla; Licht, Tine Rask; Wu, Donghai; Yu, Jun; Sung, Joseph Jao Yiu; Liang, Qiaoyi; Li, Junhua; Jia, Huijue; Lan, Zhou; Tremaroli, Valentina; Dworzynski, Piotr; Nielsen, H Bjørn; Bäckhed, Fredrik; Doré, Joël; Le Chatelier, Emmanuelle; Ehrlich, S Dusko; Lin, John C; Arumugam, Manimozhiyan; Wang, Jun; Madsen, Lise; Kristiansen, Karsten

    2015-10-01

    We established a catalog of the mouse gut metagenome comprising ∼2.6 million nonredundant genes by sequencing DNA from fecal samples of 184 mice. To secure high microbiome diversity, we used mouse strains of diverse genetic backgrounds, from different providers, kept in different housing laboratories and fed either a low-fat or high-fat diet. Similar to the human gut microbiome, >99% of the cataloged genes are bacterial. We identified 541 metagenomic species and defined a core set of 26 metagenomic species found in 95% of the mice. The mouse gut microbiome is functionally similar to its human counterpart, with 95.2% of its Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologous groups in common. However, only 4.0% of the mouse gut microbial genes were shared (95% identity, 90% coverage) with those of the human gut microbiome. This catalog provides a useful reference for future studies. PMID:26414350

  9. MUTAGENESIS SCREENING OF PESTICIDES 'DROSOPHILA'

    EPA Science Inventory

    Drosophila melanogaster males were exposed by feeding (plus contact and possibly inhalation). The genetic test found most sensitive and appropriate was the sex-linked recessive lethal test. For this, males of the Canton-S wild type stock were exposed. They were mated individually...

  10. A DNA Virus of Drosophila

    PubMed Central

    Unckless, Robert L.

    2011-01-01

    Little is known about the viruses infecting most species. Even in groups as well-studied as Drosophila, only a handful of viruses have been well-characterized. A viral metagenomic approach was used to explore viral diversity in 83 wild-caught Drosophila innubila, a mushroom feeding member of the quinaria group. A single fly that was injected with, and died from, Drosophila C Virus (DCV) was added to the sample as a control. Two-thirds of reads in the infected sample had DCV as the best BLAST hit, suggesting that the protocol developed is highly sensitive. In addition to the DCV hits, several sequences had Oryctes rhinoceros Nudivirus, a double-stranded DNA virus, as a best BLAST hit. The virus associated with these sequences was termed Drosophila innubila Nudivirus (DiNV). PCR screens of natural populations showed that DiNV was both common and widespread taxonomically and geographically. Electron microscopy confirms the presence of virions in fly fecal material similar in structure to other described Nudiviruses. In 2 species, D. innubila and D. falleni, the virus is associated with a severe (∼80–90%) loss of fecundity and significantly decreased lifespan. PMID:22053195

  11. Antibody Staining in Drosophila Germaria.

    PubMed

    Lie-Jensen, Anette; Haglund, Kaisa

    2016-01-01

    Drosophila oogenesis is a powerful model for studying a wide spectrum of cellular and developmental processes in vivo. Oogenesis starts in a specialized structure called the germarium, which harbors the stem cells for both germ and somatic cells. The germarium produces egg chambers, each of which will develop into an egg. Active areas of research in Drosophila germaria include stem cell self-renewal, division, and maintenance, cell cycle control and differentiation, oocyte specification, intercellular communication, and signaling, among others. The solid knowledge base, the genetic tractability of the Drosophila model, as well as the availability and fast development of tools and imaging techniques for oogenesis research ensure that studies in this model will keep being instrumental for novel discoveries within cell and developmental biology also in the future. This chapter focuses on antibody staining in Drosophila germaria and provides a protocol for immunostaining as well as an overview of commonly used antibodies for visualization of different cell types and cellular structures. The protocol is well-suited for subsequent confocal microscopy analyses, and in addition we present key adaptations of the protocol that are useful when performing structured illumination microscopy (SIM) super-resolution imaging. PMID:27557571

  12. Iron Absorption in Drosophila melanogaster

    PubMed Central

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-01-01

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

  13. Iron absorption in Drosophila melanogaster.

    PubMed

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-05-01

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

  14. Drosophila Photoreceptors and Signaling Mechanisms

    PubMed Central

    Katz, Ben; Minke, Baruch

    2009-01-01

    Fly eyes have been a useful biological system in which fundamental principles of sensory signaling have been elucidated. The physiological optics of the fly compound eye, which was discovered in the Musca, Calliphora and Drosophila flies, has been widely exploited in pioneering genetic and developmental studies. The detailed photochemical cycle of bistable photopigments has been elucidated in Drosophila using the genetic approach. Studies of Drosophila phototransduction using the genetic approach have led to the discovery of novel proteins crucial to many biological processes. A notable example is the discovery of the inactivation no afterpotential D scaffold protein, which binds the light-activated channel, its activator the phospholipase C and it regulator protein kinase C. An additional protein discovered in the Drosophila eye is the light-activated channel transient receptor potential (TRP), the founding member of the diverse and widely spread TRP channel superfamily. The fly eye has thus played a major role in the molecular identification of processes and proteins with prime importance. PMID:19623243

  15. Gut microbiota, obesity and diabetes.

    PubMed

    Patterson, Elaine; Ryan, Paul M; Cryan, John F; Dinan, Timothy G; Ross, R Paul; Fitzgerald, Gerald F; Stanton, Catherine

    2016-05-01

    The central role of the intestinal microbiota in the progression and, equally, prevention of metabolic dysfunction is becoming abundantly apparent. The symbiotic relationship between intestinal microbiota and host ensures appropriate development of the metabolic system in humans. However, disturbances in composition and, in turn, functionality of the intestinal microbiota can disrupt gut barrier function, a trip switch for metabolic endotoxemia. This low-grade chronic inflammation, brought about by the influx of inflammatory bacterial fragments into circulation through a malfunctioning gut barrier, has considerable knock-on effects for host adiposity and insulin resistance. Conversely, recent evidence suggests that there are certain bacterial species that may interact with host metabolism through metabolite-mediated stimulation of enteric hormones and other systems outside of the gastrointestinal tract, such as the endocannabinoid system. When the abundance of these keystone species begins to decline, we see a collapse of the symbiosis, reflected in a deterioration of host metabolic health. This review will investigate the intricate axis between the microbiota and host metabolism, while also addressing the promising and novel field of probiotics as metabolic therapies. PMID:26912499

  16. Gut failure in the ICU.

    PubMed

    Puleo, Francesco; Arvanitakis, Marianna; Van Gossum, André; Preiser, Jean-Charles

    2011-10-01

    The role of dysfunction of the gastrointestinal tract in the pathogenesis of multiple organ failure (MOF) complicating the course of critically ill patients has been suspected for more than 40 years. However, several hypotheses have been proposed and sometimes refuted to establish a link. This review summarizes the current knowledge on gastrointestinal physiology and recapitulates existing evidence on the link between gastrointestinal dysfunction and MOF. The gastrointestinal tract has various functions apart from digestion. It produces hormones with local and systemic effects, plays a major role in immunological function, and serves as a barrier against antigens within its lumen. Gastrointestinal dysfunction or gut failure is frequently encountered in critical care patients and is associated with bacterial translocation, which can lead to the development of sepsis, initiation of a cytokine-mediated systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), and death. The aim of this manuscript is to define gut failure, to review physiopathological mechanisms and clinical implications, and, finally, to suggest preventive measures. PMID:21989698

  17. Antibiotics and the gut microbiota

    PubMed Central

    Modi, Sheetal R.; Collins, James J.; Relman, David A.

    2014-01-01

    Antibiotics have been a cornerstone of innovation in the fields of public health, agriculture, and medicine. However, recent studies have shed new light on the collateral damage they impart on the indigenous host-associated communities. These drugs have been found to alter the taxonomic, genomic, and functional capacity of the human gut microbiota, with effects that are rapid and sometimes persistent. Broad-spectrum antibiotics reduce bacterial diversity while expanding and collapsing membership of specific indigenous taxa. Furthermore, antibiotic treatment selects for resistant bacteria, increases opportunities for horizontal gene transfer, and enables intrusion of pathogenic organisms through depletion of occupied natural niches, with profound implications for the emergence of resistance. Because these pervasive alterations can be viewed as an uncoupling of mutualistic host-microbe relationships, it is valuable to reconsider antimicrobial therapies in the context of an ecological framework. Understanding the biology of competitive exclusion, interspecies protection, and gene flow of adaptive functions in the gut environment may inform the design of new strategies that treat infections while preserving the ecology of our beneficial constituents. PMID:25271726

  18. Methods to assay Drosophila behavior.

    PubMed

    Nichols, Charles D; Becnel, Jaime; Pandey, Udai B

    2012-01-01

    Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular disease and various neurological diseases(1). We have optimized simple and robust behavioral assays for determining larval locomotion, adult climbing ability (RING assay), and courtship behaviors of Drosophila. These behavioral assays are widely applicable for studying the role of genetic and environmental factors on fly behavior. Larval crawling ability can be reliably used for determining early stage changes in the crawling abilities of Drosophila larvae and also for examining effect of drugs or human disease genes (in transgenic flies) on their locomotion. The larval crawling assay becomes more applicable if expression or abolition of a gene causes lethality in pupal or adult stages, as these flies do not survive to adulthood where they otherwise could be assessed. This basic assay can also be used in conjunction with bright light or stress to examine additional behavioral responses in Drosophila larvae. Courtship behavior has been widely used to investigate genetic basis of sexual behavior, and can also be used to examine activity and coordination, as well as learning and memory. Drosophila courtship behavior involves the exchange of various sensory stimuli including visual, auditory, and chemosensory signals between males and females that lead to a complex series of well characterized motor behaviors culminating in successful copulation. Traditional adult climbing assays (negative geotaxis) are tedious, labor intensive, and time consuming, with significant variation between different trials(2-4). The rapid iterative negative geotaxis (RING) assay(5) has many advantages over more widely employed protocols, providing a reproducible, sensitive, and high throughput approach to quantify adult locomotor and negative geotaxis behaviors. In the RING assay, several genotypes or drug treatments can be tested simultaneously

  19. Nucleon decay in GUT and nonGUT SUSY models

    SciTech Connect

    Murayama, Hitoshi

    1996-06-30

    I first emphasize the importance of searching for nucleon decay in the context of supersymmetric models. The status of minimal SUSY SU(5) model is reviewed, which can be definitively ruled out by a combination of superKamiokande andLEP-2 experiments. Non-minimal models may provide some suppression in the nucleon decay rates, but there is still a good chance for superKamiokande. I point out that the operators suppressed even by the Planck-scale are too large. We need a suppression mechanism for the operators at the level of 10-7, and the mechanism, I argue, may well be a flavor symmetry. A particular example predicts p --> K0e+ to be the dominant mode which does not arise in GUT models.

  20. Beyond the gut bacterial microbiota: The gut virome.

    PubMed

    Columpsi, Paola; Sacchi, Paolo; Zuccaro, Valentina; Cima, Serena; Sarda, Cristina; Mariani, Marcello; Gori, Andrea; Bruno, Raffaele

    2016-09-01

    The gastrointestinal tract is colonized with a highly different population of bacterial, viral, ad fungal species; viruses are reported to be dominant. The composition of gut virome is closely related to dietary habits and surrounding environment. Host and their intestinal microbes live in a dynamic equilibrium and viruses stimulate a low degree of immune responses without causing symptoms (host tolerance). However, intestinal phages could lead to a rupture of eubiosis and may contribute to the shift from health to disease in humans and animals. Viral nucleic acids and other products of lysis of bacteria serve as pathogen-associated molecular patterns (PAMPs) and could trigger specific inflammatory modulations. At the same time, phages could elicit innate antiviral immune responses. Toll-like receptors (TLRs) operated as innate antiviral immune sensors and their activation triggers signaling cascades that lead to inflammatory response. J. Med. Virol. 88:1467-1472, 2016. © 2016 Wiley Periodicals, Inc. PMID:26919534

  1. Time-lapse imaging reveals stereotypical patterns of Drosophila midline glial migration.

    PubMed

    Wheeler, Scott R; Pearson, Joseph C; Crews, Stephen T

    2012-01-15

    The Drosophila CNS midline glia (MG) are multifunctional cells that ensheath and provide trophic support to commissural axons, and direct embryonic development by employing a variety of signaling molecules. These glia consist of two functionally distinct populations: the anterior MG (AMG) and posterior MG (PMG). Only the AMG ensheath axon commissures, whereas the function of the non-ensheathing PMG is unknown. The Drosophila MG have proven to be an excellent system for studying glial proliferation, cell fate, apoptosis, and axon-glial interactions. However, insight into how AMG migrate and acquire their specific positions within the axon-glial scaffold has been lacking. In this paper, we use time-lapse imaging, single-cell analysis, and embryo staining to comprehensively describe the proliferation, migration, and apoptosis of the Drosophila MG. We identified 3 groups of MG that differed in the trajectories of their initial inward migration: AMG that migrate inward and to the anterior before undergoing apoptosis, AMG that migrate inward and to the posterior to ensheath commissural axons, and PMG that migrate inward and to the anterior to contact the commissural axons before undergoing apoptosis. In a second phase of their migration, the surviving AMG stereotypically migrated posteriorly to specific positions surrounding the commissures, and their final position was correlated with their location prior to migration. Most noteworthy are AMG that migrated between the commissures from a ventral to a dorsal position. Single-cell analysis indicated that individual AMG possessed wide-ranging and elaborate membrane extensions that partially ensheathed both commissures. These results provide a strong foundation for future genetic experiments to identify mutants affecting MG development, particularly in guidance cues that may direct migration. Drosophila MG are homologous in structure and function to the glial-like cells that populate the vertebrate CNS floorplate, and study

  2. Characterization of msim, a murine homologue of the Drosophila sim transcription factor

    SciTech Connect

    Moffett, P.; Reece, M.; Pelletier, J.

    1996-07-01

    Mutations in the Drosophila single-minded (sim) gene result in loss of precursor cells that give rise to midline cells of the embryonic central nervous system. During the course of an exon-trapping strategy aimed at identifying transcripts that contribute to the etiology and pathophysiology of Down syndrome, we identified a human exon from the Down syndrome, we identified a human exon from the Down syndrome critical region showing significantly homology to the Drosophila sim gene. Using a cross-hybridization approach, we have isolated a murine homolog of Drosophila sim gene, which we designated msim. Nucleotide and predicted amino acid sequence analyses of msim cDNA clones indicate the this gene encodes a member of the basic-helix-loop-helix class of transcription factors. The murine and Drosophila proteins share 88% residues within the basic-helix-loop helix domain, with an overall homology of 92%. In addition, the N-terminal domain of MSIM contains two PAS dimerization motifs also featured in the Drosophila sim gene product, as well as a small number of other transcription factors. Northern blot analysis of adult murine tissues revealed that the msim gene produces a single mRNA species of {approximately}4 kb expressed in a small number of tissues, with the highest levels in the kidneys and lower levels present in skeletal muscle, lung, testis, brain, and heart. In situ hybridization experiments demonstrate that msim is also expressed in early fetal development in the central nervous system and in cartilage primordia. The characteristics of the msim gene are consistent with its putative function as a transcriptional regulator. 51 refs., 6 figs., 1 tab.

  3. Time-lapse Imaging Reveals Stereotypical Patterns of Drosophila Midline Glial Migration

    PubMed Central

    Wheeler, Scott R.; Pearson, Joseph C.; Crews, Stephen T.

    2011-01-01

    The Drosophila CNS midline glia (MG) are multifunctional cells that ensheath and provide trophic support to commissural axons, and direct embryonic development by employing a variety of signaling molecules. These glia consist of two functionally distinct populations: the anterior MG (AMG) and posterior MG (PMG). Only the AMG ensheath axon commissures, whereas the function of the non-ensheathing PMG is unknown. The Drosophila MG have proven to be an excellent system for studying glial proliferation, cell fate, apoptosis, and axon-glial interactions. However, insight into how AMG migrate and acquire their specific positions within the axon-glial scaffold has been lacking. In this paper, we use time-lapse imaging, single-cell analysis, and embryo staining to comprehensively describe the proliferation, migration, and apoptosis of the Drosophila MG. We identified 3 groups of MG that differed in the trajectories of their initial inward migration: AMG that migrate inward and to the anterior before undergoing apoptosis, AMG that migrate inward and to the posterior to ensheath commissural axons, and PMG that migrate inward and to the anterior to contact the commissural axons before undergoing apoptosis. In a second phase of their migration, the surviving AMG stereotypically migrated posteriorly to specific positions surrounding the commissures, and their final position was correlated with their location prior to migration. Most noteworthy are AMG that migrated between the commissures from a ventral to a dorsal position. Single-cell analysis indicated that individual AMG possessed wide-ranging and elaborate membrane extensions that partially ensheathed both commissures. These results provide a strong foundation for future genetic experiments to identify mutants affecting MG development, particularly in guidance cues that may direct migration. Drosophila MG are homologous in structure and function to the glial-like cells that populate the vertebrate CNS floorplate, and study

  4. Characterization of msim, a murine homologue of the Drosophila sim transcription factor.

    PubMed

    Moffett, P; Dayo, M; Reece, M; McCormick, M K; Pelletier, J

    1996-07-01

    Mutations in the Drosophila single-minded (sim) gene result in loss of precursor cells that give rise to midline cells of the embryonic central nervous system. During the course of an exon-trapping strategy aimed at identifying transcripts that contribute to the etiology and pathophysiology of Down syndrome, we identified a human exon from the Down syndrome critical region showing significant homology to the Drosophila sim gene. Using a cross-hybridization approach, we have isolated a murine homolog of the Drosophila sim gene, which we designated msim. Nucleotide and predicted amino acid sequence analyses of msim cDNA clones indicate that this gene encodes a member of the basic-helix-loop-helix class of transcription factors. The murine and Drosophila proteins share 88% residues within the basic-helix-loop-helix domain, with an overall homology of 92%. In addition, the N-terminal domain of MSIM contains two PAS dimerization motifs also featured in the Drosophila sim gene product, as well as a small number of other transcription factors. Northern blot analysis of adult murine tissues revealed that the msim gene produces a single mRNA species of approximately 4 kb expressed in a small number of tissues, with the highest levels in the kidneys and lower levels present in skeletal muscle, lung, testis, brain, and heart. In situ hybridization experiments demonstrate that msim is also expressed in early fetal development in the central nervous system and in cartilage primordia. The characteristics of the msim gene are consistent with its putative function as a transcriptional regulator. PMID:8661115

  5. Spatio-Temporal Plasticity in Chromatin Organization in Mouse Cell Differentiation and during Drosophila Embryogenesis

    PubMed Central

    Bhattacharya, Dipanjan; Talwar, Shefali; Mazumder, Aprotim; Shivashankar, G.V.

    2009-01-01

    Cellular differentiation and developmental programs require changing patterns of gene expression. Recent experiments have revealed that chromatin organization is highly dynamic within living cells, suggesting possible mechanisms to alter gene expression programs, yet the physical basis of this organization is unclear. In this article, we contrast the differences in the dynamic organization of nuclear architecture between undifferentiated mouse embryonic stem cells and terminally differentiated primary mouse embryonic fibroblasts. Live-cell confocal tracking of nuclear lamina evidences highly flexible nuclear architecture within embryonic stem cells as compared to primary mouse embryonic fibroblasts. These cells also exhibit significant changes in histone and heterochromatin binding proteins correlated with their distinct epigenetic signatures as quantified by immunofluorescence analysis. Further, we follow histone dynamics during the development of the Drosophila melanogaster embryo, which gives an insight into spatio-temporal evolution of chromatin plasticity in an organismal context. Core histone dynamics visualized by fluorescence recovery after photobleaching, fluorescence correlation spectroscopy, and fluorescence anisotropy within the developing embryo, revealed an intriguing transition from plastic to frozen chromatin assembly synchronous with cellular differentiation. In the embryo, core histone proteins are highly mobile before cellularization, actively exchanging with the pool in the yolk. This hyperdynamic mobility decreases as cellularization and differentiation programs set in. These findings reveal a direct correlation between the dynamic transitions in chromatin assembly with the onset of cellular differentiation and developmental programs. PMID:19413989

  6. Culture and Manipulation of Embryonic Cells

    PubMed Central

    Edgar, Lois G.; Goldstein, Bob

    2012-01-01

    The direct manipulation of embryonic cells is an important tool for addressing key questions in cell and developmental biology. C. elegans is relatively unique among genetic model systems in being amenable to manipulation of embryonic cells. Embryonic cell manipulation has allowed the identification of cell interactions by direct means, and it has been an important technique for dissecting mechanisms by which cell fates are specified, cell divisions are oriented, and morphogenesis is accomplished. Here, we present detailed methods for isolating, manipulating and culturing embryonic cells of C. elegans. PMID:22226523

  7. Testing GUTs: where do monopoles fit

    SciTech Connect

    Ellis, J.

    1982-10-01

    The report shows why the inadequacies of the standard model of elementary particles impel some theorists toward embedding the strong, weak and electromagnetic interactions in a simple GUT group, and explains why the grand unification scale and hence the GUM (Grand Unified Monopoles) mass are expected to be so large (greater than or equal to 10/sup 14/ GeV). It goes on to describe some model GUTs, notably minimal SU(5) and supersymmetric (susy) GUTs. The grand unified analogues of generalized Cabibbo mixing angles are introduced relevant to the prediction of baryon decay modes in different theories as well as to the Decay modes catalyzed by GUMs. Phenomenologies of conventional and susy GUTs are contrasted including the potential increase in the grand unification scale as well as possible different baryon decay modes in susy GUTs. The phenomenology of GUMs is discussed, principally their ability to catalyze baryon decays. Some of the astrophysical and cosmological constraints on GUMs, GUMs, which make it difficult to imagine ever seeing a GUM and may impose serious restrictions on GUT model-building via their behavior in the very early universe are introduced. Finally, the reasons why GUMs are crucial aspects and tests of GUTs are summarized.

  8. Arthritis susceptibility and the Gut Microbiome

    PubMed Central

    Taneja, Veena

    2014-01-01

    Summary Rheumatoid arthritis (RA) is an autoimmune disease with unknown etiology though both genetic and environmental factors have been suggested to be involved in its pathogenesis. While infections and other environmental factors like smoking have been studies extensively and show some association, a direct link between all the factors has been difficult to prove. With the recent advances in technology, it has become possible to sequence the commensals that are residing in our gut. The gut microbiome may provide the missing link to this puzzle and help solve the mystery of many leaky gut syndromes. The gut commensals are involved in maintaining host immune homeostasis and function suggesting that they might be critical in altering the immune system that leads to autoimmune diseases like RA. Mouse models support the role of the gut microbiota in predisposition to RA. If that is true, the power of gut-derived commensal can be harnessed to our benefit by generating a biomarker profile along with genetic factors to define individuals at risk and by altering the gut microbial composition using various means. PMID:24873878

  9. Irritable Bowel Syndrome, Gut Microbiota and Probiotics

    PubMed Central

    Lee, Beom Jae

    2011-01-01

    Irritable bowel syndrome (IBS) is a complex disorder characterized by abdominal symptoms including chronic abdominal pain or discomfort and altered bowel habits. The etiology of IBS is multifactorial, as abnormal gut motility, visceral hypersensitivity, disturbed neural function of the brain-gut axis and an abnormal autonomic nervous system are all implicated in disease progression. Based on recent experimental and clinical studies, it has been suggested that additional etiological factors including low-grade inflammation, altered gut microbiota and alteration in the gut immune system play important roles in the pathogenesis of IBS. Therefore, therapeutic restoration of altered intestinal microbiota may be an ideal treatment for IBS. Probiotics are live organisms that are believed to cause no harm and result in health benefits for the host. Clinical efficacy of probiotics has been shown in the treatment or prevention of some gastrointestinal inflammation-associated disorders including traveler's diarrhea, antibiotics-associated diarrhea, pouchitis of the restorative ileal pouch and necrotizing enterocolitis. The molecular mechanisms, as cause of IBS pathogenesis, affected by altered gut microbiota and gut inflammation-immunity are reviewed. The effect of probiotics on the gut inflammation-immune systems and the results from clinical trials of probiotics for the treatment of IBS are also summarized. PMID:21860817

  10. Role of bombesin on gut mucosal growth.

    PubMed Central

    Chu, K U; Evers, B M; Ishizuka, J; Townsend, C M; Thompson, J C

    1995-01-01

    OBJECTIVE: The authors examined the effects of exogenous bombesin (BBS) on gut mucosal growth in chow-fed rats and the mucosal regeneration after gut atrophy brought about by feeding an elemental diet and after intestinal injury produced by methotrexate (MTX). SUMMARY BACKGROUND DATA: Bombesin is one of many gastrointestinal peptides implicated in the regulation of gut mucosal growth. Although BBS is known to stimulate growth of normal pancreatic tissue, the trophic effect of BBS on gut mucosa is less clear and its exact role in gut mucosal regeneration and repair is not known. METHODS: Rats were fed a regular chow diet (control) or an elemental diet plus either saline or BBS (10 micrograms/kg). In another experiment, rats fed a chow diet and treated with saline or BBS were given MTX (20 micrograms/kg) or a single intraperitoneal injection. In all experiments, small and large bowel mucosa and pancreas were removed and analyzed for BBS-mediated proliferation. RESULTS: Bombesin produced significant mucosal proliferation of the small bowel at day 14, but not at day 7, in rats fed regular chow. In contrast, BBS treatment for 7 days produced significant proliferation in both the atrophic and injured gut mucosa of rats given elemental diet or MTX. CONCLUSIONS: Bombesin may be an important enterotrophic factor for normal mucosal proliferation and may be clinically beneficial as an agent to restore or maintain gut mucosa during periods of atrophy or injury. PMID:7618976

  11. Supersymmetric F-theory GUT models

    NASA Astrophysics Data System (ADS)

    Chung, Yu-Chieh

    F-theory is a twelve-dimensional geometric version of string theory and is believed to be a natural framework for GUT model building. The aim of this dissertation is to study how gauge theories realized by F-theory can accommodate GUT models. In this dissertation, we focus on local and semi-local GUT model building in F-theory. For local GUT models, we build SU(5) GUTs by using abelian U(1) fluxes via theSU6) gauge group. Doing so, we obtain non-minimal spectra of the MSSM with doublet-triplet splitting by switching on abelian U(1)2 fluxes. We also classify all supersymmetric U(1)2 fluxes by requiring an exotic-free bulk spectrum. For semi-local GUT models, we start with an E8 singularity and obtain lower rank gauge groups by unfolding the singularity governed by spectral covers. In this framework, the spectra can be calculated by the intersection numbers of spectral covers and matter curves. In particular, we useSU4) spectral covers and abelian U(1)X fluxes to build flippedSU5) models. We show that three-generation spectra of flippedSU5) models can be achieved by turning on suitable fluxes. To construct E6 GUTs, we consider SU3) spectral covers breaking E8 down to E6. Also three-generation extended MSSM can be obtained by using non-abelian SU2) x U(1)2 fluxes.

  12. Circular DNA Molecules in the Genus Drosophila

    PubMed Central

    Travaglini, E. C.; Schultz, J.

    1972-01-01

    The satellite DNA's from the embryos of five species of Drosophila (D. melanogaster, D. simulans, D. nasuta, D. virilis and D. hydei) have been analyzed for the presence of closed circular duplex DNA molecules, as determined by CsCl-EBr gradients. Circular DNA molecules were found in every species but D. melanogaster. Analyses of cell fractions from adult Drosophila and organ fractions from Drosophila larvae show that fractions containing mitochondria are highly enriched in these molecules. PMID:4643820

  13. Stepwise Progression of Embryonic Patterning.

    PubMed

    Sandler, Jeremy E; Stathopoulos, Angelike

    2016-07-01

    It is long established that the graded distribution of Dorsal transcription factor influences spatial domains of gene expression along the dorsoventral (DV) axis of Drosophila melanogaster embryos. However, the more recent realization that Dorsal levels also change with time raises the question of whether these dynamics are instructive. An overview of DV axis patterning is provided, focusing on new insights identified through quantitative analysis of temporal changes in Dorsal target gene expression from one nuclear cycle to the next ('steps'). Possible roles for the stepwise progression of this patterning program are discussed including (i) tight temporal regulation of signaling pathway activation, (ii) control of gene expression cohorts, and (iii) ensuring the irreversibility of the patterning and cell fate specification process. PMID:27230753

  14. kuzbanian-mediated cleavage of Drosophila Notch

    PubMed Central

    Lieber, Toby; Kidd, Simon; Young, Michael W.

    2002-01-01

    Loss of Kuzbanian, a member of the ADAM family of metalloproteases, produces neurogenic phenotypes in Drosophila. It has been suggested that this results from a requirement for kuzbanian-mediated cleavage of the Notch ligand Delta. Using transgenic Drosophila expressing transmembrane Notch proteins, we show that kuzbanian, independent of any role in Delta processing, is required for the cleavage of Notch. We show that Kuzbanian can physically associate with Notch and that removal of kuzbanian activity by RNA-mediated interference in Drosophila tissue culture cells eliminates processing of ligand-independent transmembrane Notch molecules. Our data suggest that in Drosophila, kuzbanian can mediate S2 cleavage of Notch. PMID:11799064

  15. The Hippo pathway regulates intestinal stem cell proliferation during Drosophila adult midgut regeneration

    PubMed Central

    Shaw, Rachael L.; Kohlmaier, Alexander; Polesello, Cédric; Veelken, Cornelia; Edgar, Bruce A.; Tapon, Nicolas

    2010-01-01

    Intestinal stem cells (ISCs) in the adult Drosophila midgut proliferate to self-renew and to produce differentiating daughter cells that replace those lost as part of normal gut function. Intestinal stress induces the activation of Upd/Jak/Stat signalling, which promotes intestinal regeneration by inducing rapid stem cell proliferation. We have investigated the role of the Hippo (Hpo) pathway in the Drosophila intestine (midgut). Hpo pathway inactivation in either the ISCs or the differentiated enterocytes induces a phenotype similar to that observed under stress situations, including increased stem cell proliferation and expression of Jak/Stat pathway ligands. Hpo pathway targets are induced by stresses such as bacterial infection, suggesting that the Hpo pathway functions as a sensor of cellular stress in the differentiated cells of the midgut. In addition, Yki, the pro-growth transcription factor target of the Hpo pathway, is required in ISCs to drive the proliferative response to stress. Our results suggest that the Hpo pathway is a mediator of the regenerative response in the Drosophila midgut. PMID:21068063

  16. Drosophila sec10 is required for hormone secretion but not general exocytosis or neurotransmission.

    PubMed

    Andrews, Hillary K; Zhang, Yong Q; Trotta, Nick; Broadie, Kendal

    2002-12-01

    The sec6/8, or exocyst, complex is implicated in trafficking of secretory vesicles to fusion sites in the plasma membrane. Genetic analyses have been done primarily in yeast, where mutation of the eight protein subunits similarly disrupts polarized vesicle fusion. The goal of this study was to assay the sec6/8 complex in Drosophila, and specifically to test its widely hypothesized functions in synaptogenesis and neurotransmission. We used a transgenic RNAi approach to remove the most highly conserved complex component, Drosophila sec10 (dSec10). Ubiquitous dSec10 RNAi resulted in early postembryonic lethality, demonstrating that dSec10 is essential. Surprisingly, tissue-specific dSec10 RNAi revealed no essential requirement in nervous system, musculature, gut or epidermis. Assays of polarized secretion in all these tissues failed to reveal any role for dSec10. In particular, the neuromuscular synapse showed no defects in morphogenesis or vesicle trafficking/fusion underlying neurotransmission. The essential requirement for dSec10 was restricted to the ring gland, the Drosophila organ specialized for endocrine function. The developmental arrest of dSec10 RNAi animals was partially rescued by feeding ecdysone, suggesting dSec10 mediates steroid hormone secretion. We conclude that dSec10 has no detectable role in most forms of polarized trafficking/exocytosis, including neurotransmission, but rather is essential for endocrine secretion. PMID:12453153

  17. Reduced insulin/insulin-like growth factor signaling decreases translation in Drosophila and mice

    PubMed Central

    Essers, Paul; Tain, Luke S.; Nespital, Tobias; Goncalves, Joana; Froehlich, Jenny; Partridge, Linda

    2016-01-01

    Down-regulation of insulin/insulin-like growth factor signaling (IIS) can increase lifespan in C. elegans, Drosophila and mice. In C. elegans, reduced IIS results in down-regulation of translation, which itself can extend lifespan. However, the effect of reduced IIS on translation has yet to be determined in other multicellular organisms. Using two long-lived IIS models, namely Drosophila lacking three insulin-like peptides (dilp2-3,5−/−) and mice lacking insulin receptor substrate 1 (Irs1−/−), and two independent translation assays, polysome profiling and radiolabeled amino acid incorporation, we show that reduced IIS lowers translation in these organisms. In Drosophila, reduced IIS decreased polysome levels in fat body and gut, but reduced the rate of protein synthesis only in the fat body. Reduced IIS in mice decreased protein synthesis rate only in skeletal muscle, without reducing polysomes in any tissue. This lowered translation in muscle was independent of Irs1 loss in the muscle itself, but a secondary effect of Irs1 loss in the liver. In conclusion, down-regulation of translation is an evolutionarily conserved response to reduced IIS, but the tissues in which it occurs can vary between organisms. Furthermore, the mechanisms underlying lowered translation may differ in mice, possibly associated with the complexity of the regulatory processes. PMID:27452396

  18. Reduced insulin/insulin-like growth factor signaling decreases translation in Drosophila and mice.

    PubMed

    Essers, Paul; Tain, Luke S; Nespital, Tobias; Goncalves, Joana; Froehlich, Jenny; Partridge, Linda

    2016-01-01

    Down-regulation of insulin/insulin-like growth factor signaling (IIS) can increase lifespan in C. elegans, Drosophila and mice. In C. elegans, reduced IIS results in down-regulation of translation, which itself can extend lifespan. However, the effect of reduced IIS on translation has yet to be determined in other multicellular organisms. Using two long-lived IIS models, namely Drosophila lacking three insulin-like peptides (dilp2-3,5(-/-)) and mice lacking insulin receptor substrate 1 (Irs1(-/-)), and two independent translation assays, polysome profiling and radiolabeled amino acid incorporation, we show that reduced IIS lowers translation in these organisms. In Drosophila, reduced IIS decreased polysome levels in fat body and gut, but reduced the rate of protein synthesis only in the fat body. Reduced IIS in mice decreased protein synthesis rate only in skeletal muscle, without reducing polysomes in any tissue. This lowered translation in muscle was independent of Irs1 loss in the muscle itself, but a secondary effect of Irs1 loss in the liver. In conclusion, down-regulation of translation is an evolutionarily conserved response to reduced IIS, but the tissues in which it occurs can vary between organisms. Furthermore, the mechanisms underlying lowered translation may differ in mice, possibly associated with the complexity of the regulatory processes. PMID:27452396

  19. Diet, gut microbiome, and bone health.

    PubMed

    Weaver, Connie M

    2015-04-01

    Interactions between the environment, the gut microbiome, and host characteristics that influence bone health are beginning to be explored. This is the first area where functional benefits from diet-induced changes in the gut microbiome have been reported for healthy people. Several prebiotics that reach the lower intestine have resulted in an altered gut microbiome that is thought to enhance fermentation of the fibers to produce short-chain fatty acids. These changes are positively correlated with increases in fractional calcium absorption in adolescents and with increases in measures of bone density and strength in animal models. New methodologies are available to explore mechanisms and to refine intervention strategies. PMID:25616772

  20. Mosquito gut antiparasitic and antiviral immunity.

    PubMed

    Saraiva, Raúl G; Kang, Seokyoung; Simões, Maria L; Angleró-Rodríguez, Yesseinia I; Dimopoulos, George

    2016-11-01

    Mosquitoes are responsible for the transmission of diseases with a serious impact on global human health, such as malaria and dengue. All mosquito-transmitted pathogens complete part of their life cycle in the insect gut, where they are exposed to mosquito-encoded barriers and active factors that can limit their development. Here we present the current understanding of mosquito gut immunity against malaria parasites, filarial worms, and viruses such as dengue, Chikungunya, and West Nile. The most recently proposed immune mediators involved in intestinal defenses are discussed, as well as the synergies identified between the recognition of gut microbiota and the mounting of the immune response. PMID:26827888

  1. Diet, Gut Microbiome, and Bone Health

    PubMed Central

    2016-01-01

    Interactions between the environment, the gut microbiome, and host characteristics that influence bone health are beginning to be explored. This is the first area where functional benefits from diet-induced changes in the gut microbiome have been reported for healthy people. Several prebiotics that reach the lower intestine have resulted in an altered gut microbiome that is thought to enhance fermentation of the fibers to produce short-chain fatty acids. These changes are positively correlated with increases in fractional calcium absorption in adolescents and with increases in measures of bone density and strength in animal models. New methodologies are available to explore mechanisms and to refine intervention strategies. PMID:25616772

  2. Evolution of host specialization in gut microbes: the bee gut as a model

    PubMed Central

    Kwong, Waldan K; Moran, Nancy A

    2015-01-01

    Bacterial symbionts of eukaryotes often give up generalist lifestyles to specialize to particular hosts. The eusocial honey bees and bumble bees harbor two such specialized gut symbionts, Snodgrassella alvi and Gilliamella apicola. Not only are these microorganisms specific to bees, but different strains of these bacteria tend to assort according to host species. By using in-vivo microbial transplant experiments, we show that the observed specificity is, at least in part, due to evolved physiological barriers that limit compatibility between a host and a potential gut colonizer. How and why such specialization occurs is largely unstudied for gut microbes, despite strong evidence that it is a general feature in many gut communities. Here, we discuss the potential factors that favor the evolution of host specialization, and the parallels that can be drawn with parasites and other symbiont systems. We also address the potential of the bee gut as a model for exploring gut community evolution. PMID:26011669

  3. Gut Microbiota and Extreme Longevity.

    PubMed

    Biagi, Elena; Franceschi, Claudio; Rampelli, Simone; Severgnini, Marco; Ostan, Rita; Turroni, Silvia; Consolandi, Clarissa; Quercia, Sara; Scurti, Maria; Monti, Daniela; Capri, Miriam; Brigidi, Patrizia; Candela, Marco

    2016-06-01

    The study of the extreme limits of human lifespan may allow a better understanding of how human beings can escape, delay, or survive the most frequent age-related causes of morbidity, a peculiarity shown by long-living individuals. Longevity is a complex trait in which genetics, environment, and stochasticity concur to determine the chance to reach 100 or more years of age [1]. Because of its impact on human metabolism and immunology, the gut microbiome has been proposed as a possible determinant of healthy aging [2, 3]. Indeed, the preservation of host-microbes homeostasis can counteract inflammaging [4], intestinal permeability [5], and decline in bone and cognitive health [6, 7]. Aiming at deepening our knowledge on the relationship between the gut microbiota and a long-living host, we provide for the first time the phylogenetic microbiota analysis of semi-supercentenarians, i.e., 105-109 years old, in comparison to adults, elderly, and centenarians, thus reconstructing the longest available human microbiota trajectory along aging. We highlighted the presence of a core microbiota of highly occurring, symbiotic bacterial taxa (mostly belonging to the dominant Ruminococcaceae, Lachnospiraceae, and Bacteroidaceae families), with a cumulative abundance decreasing along with age. Aging is characterized by an increasing abundance of subdominant species, as well as a rearrangement in their co-occurrence network. These features are maintained in longevity and extreme longevity, but peculiarities emerged, especially in semi-supercentenarians, describing changes that, even accommodating opportunistic and allochthonous bacteria, might possibly support health maintenance during aging, such as an enrichment and/or higher prevalence of health-associated groups (e.g., Akkermansia, Bifidobacterium, and Christensenellaceae). PMID:27185560

  4. A mutant O-GlcNAcase as a probe to reveal global dynamics of the Drosophila O-GlcNAc developmental proteome

    PubMed Central

    Borodkin, Vladimir; Alonso, Jana; Ferenbach, Andrew T.; Shepherd, Claire; Navratilova, Iva Hopkins; vanAalten, Daan M. F.

    2016-01-01

    Nucleocytoplasmic protein O-GlcNAcylation is essential for embryogenesis. The dynamics of the O-GlcNAc proteome and the underlying mechanistic biology linking it to embryonic development is not understood. Harnessing the unusual properties of an O-GlcNAcase mutant that binds O-GlcNAc sites with nanomolar affinity, we uncover changes in O-GlcNAc proteins as a function of Drosophila development. PMID:26348912

  5. Generative models: Human embryonic stem cells and multiple modeling relations.

    PubMed

    Fagan, Melinda Bonnie

    2016-04-01

    Model organisms are at once scientific models and concrete living things. It is widely assumed by philosophers of science that (1) model organisms function much like other kinds of models, and (2) that insofar as their scientific role is distinctive, it is in virtue of representing a wide range of biological species and providing a basis for generalizations about those targets. This paper uses the case of human embryonic stem cells (hESC) to challenge both assumptions. I first argue that hESC can be considered model organisms, analogous to classic examples such as Escherichia coli and Drosophila melanogaster. I then discuss four contrasts between the epistemic role of hESC in practice, and the assumptions about model organisms noted above. These contrasts motivate an alternative view of model organisms as a network of systems related constructively and developmentally to one another. I conclude by relating this result to other accounts of model organisms in recent philosophy of science. PMID:27083092

  6. A Drosophila complementary DNA resource

    SciTech Connect

    Rubin, Gerald M.; Hong, Ling; Brokstein, Peter; Evans-Holm, Martha; Frise, Erwin; Stapleton, Mark; Harvey, Damon A.

    2000-03-24

    Collections of nonredundant, full-length complementary DNA (cDNA) clones for each of the model organisms and humans will be important resources for studies of gene structure and function. We describe a general strategy for producing such collections and its implementation, which so far has generated a set of cDNAs corresponding to over 40% of the genes in the fruit fly Drosophila melanogaster.

  7. Virus isolation and propagation in embryonating eggs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The embryonating egg is one of the most versatile, easy to work with, and widely used host systems for the isolation and propagation of avian viruses. The embryonating chicken egg (ECE) is the most commonly available system that is both specific pathogen free and supports the replication of viruses...

  8. Regulation of the BMP Signaling-Responsive Transcriptional Network in the Drosophila Embryo.

    PubMed

    Deignan, Lisa; Pinheiro, Marco T; Sutcliffe, Catherine; Saunders, Abbie; Wilcockson, Scott G; Zeef, Leo A H; Donaldson, Ian J; Ashe, Hilary L

    2016-07-01

    The BMP signaling pathway has a conserved role in dorsal-ventral axis patterning during embryonic development. In Drosophila, graded BMP signaling is transduced by the Mad transcription factor and opposed by the Brinker repressor. In this study, using the Drosophila embryo as a model, we combine RNA-seq with Mad and Brinker ChIP-seq to decipher the BMP-responsive transcriptional network underpinning differentiation of the dorsal ectoderm during dorsal-ventral axis patterning. We identify multiple new BMP target genes, including positive and negative regulators of EGF signaling. Manipulation of EGF signaling levels by loss- and gain-of-function studies reveals that EGF signaling negatively regulates embryonic BMP-responsive transcription. Therefore, the BMP gene network has a self-regulating property in that it establishes a balance between its activity and that of the antagonistic EGF signaling pathway to facilitate correct patterning. In terms of BMP-dependent transcription, we identify key roles for the Zelda and Zerknüllt transcription factors in establishing the resulting expression domain, and find widespread binding of insulator proteins to the Mad and Brinker-bound genomic regions. Analysis of embryos lacking the BEAF-32 insulator protein shows reduced transcription of a peak BMP target gene and a reduction in the number of amnioserosa cells, the fate specified by peak BMP signaling. We incorporate our findings into a model for Mad-dependent activation, and discuss its relevance to BMP signal interpretation in vertebrates. PMID:27379389

  9. Regulation of the BMP Signaling-Responsive Transcriptional Network in the Drosophila Embryo

    PubMed Central

    Saunders, Abbie; Wilcockson, Scott G.; Zeef, Leo A. H.; Donaldson, Ian J.; Ashe, Hilary L.

    2016-01-01

    The BMP signaling pathway has a conserved role in dorsal-ventral axis patterning during embryonic development. In Drosophila, graded BMP signaling is transduced by the Mad transcription factor and opposed by the Brinker repressor. In this study, using the Drosophila embryo as a model, we combine RNA-seq with Mad and Brinker ChIP-seq to decipher the BMP-responsive transcriptional network underpinning differentiation of the dorsal ectoderm during dorsal-ventral axis patterning. We identify multiple new BMP target genes, including positive and negative regulators of EGF signaling. Manipulation of EGF signaling levels by loss- and gain-of-function studies reveals that EGF signaling negatively regulates embryonic BMP-responsive transcription. Therefore, the BMP gene network has a self-regulating property in that it establishes a balance between its activity and that of the antagonistic EGF signaling pathway to facilitate correct patterning. In terms of BMP-dependent transcription, we identify key roles for the Zelda and Zerknüllt transcription factors in establishing the resulting expression domain, and find widespread binding of insulator proteins to the Mad and Brinker-bound genomic regions. Analysis of embryos lacking the BEAF-32 insulator protein shows reduced transcription of a peak BMP target gene and a reduction in the number of amnioserosa cells, the fate specified by peak BMP signaling. We incorporate our findings into a model for Mad-dependent activation, and discuss its relevance to BMP signal interpretation in vertebrates. PMID:27379389

  10. Activity, Expression and Function of a Second Drosophila Protein Kinase a Catalytic Subunit Gene

    PubMed Central

    Melendez, A.; Li, W.; Kalderon, D.

    1995-01-01

    The DC2 gene was isolated previously on the basis of sequence similarity to DCO, the major Drosophila protein kinase A (PKA) catalytic subunit gene. We show here that the 67-kD Drosophila DC2 protein behaves as a PKA catalytic subunit in vitro. DC2 is transcribed in mesodermal anlagen of early embryos. This expression depends on dorsal but on neither twist nor snail activity. DC2 transcriptional fusions mimic this embryonic expression and are also expressed in subsets of cells in the optic lamina, wing disc and leg discs of third instar larvae. A saturation screen of a small deficiency interval containing DC2 for recessive lethal mutations yielded no DC2 alleles. We therefore isolated new deficiencies to generate deficiency trans-heterozygotes that lacked DC2 activity. These animals were viable and fertile. The absence of DC2 did not affect the viability or phenotype of imaginal disc cells lacking DC0 activity or embryonic hatching of animals with reduced DC0 activity. Furthermore, transgenes expressing DC2 from a DC0 promoter did not efficiently rescue a variety of DC0 mutant phenotypes. These observations indicate that DC2 is not an essential gene and is unlikely to be functionally redundant with DC0, which has multiple unique functions during development. PMID:8601490

  11. [The gut microbiota in sickness and health].

    PubMed

    Lankelma, Jacqueline M; Nieuwdorp, Max; de Vos, Willem M; Wiersinga, W Joost

    2014-01-01

    The human gut microbiota, formerly known as 'gut flora', may be regarded as an external organ with many physiological functions in metabolism, development of the immune system and defense against pathogens. The adult gut microbiota consist of 1013-1014 micro-organisms. The aggregate genome of these, known as the microbiome, is 100 times larger than the human genome. The gut microbiotica may be involved in the pathogenesis of a range of syndromes, such as inflammatory bowel disease, obesity, diabetes mellitus and atopic disorders. It should be noted that until now most of the studies conducted have been association studies, without proof of causality. This increasing insight has led to identification of new therapeutic strategies, which are currently being investigated in clinical studies. Although the implications of this knowledge for individual patients have yet to become clear, various interventions are conceivable, such as supplementation of nutritional elements, prebiotics or probiotics and feces transplantation. PMID:24780568

  12. Villification: How the Gut Gets Its Villi

    PubMed Central

    Shyer, Amy E.; Tallinen, Tuomas; Nerurkar, Nandan L.; Wei, Zhiyan; Gil, Eun Seok; Kaplan, David L.; Tabin, Clifford J.; Mahadevan, L.

    2014-01-01

    The villi of the human and chick gut are formed in similar step-wise progressions, wherein the mesenchyme and attached epithelium first fold into longitudinal ridges, then a zigzag pattern, and finally individual villi. We find that these steps of villification depend upon the sequential differentiation of the distinct smooth muscle layers of the gut, which restrict the expansion of the growing endoderm and mesenchyme, generating compressive stresses that lead to their buckling and folding. A quantitative computational model, incorporating measured properties of the developing gut, recapitulates the morphological patterns seen during villification in a variety of species. These results provide a mechanistic understanding of the formation of these elaborations of the lining of the gut, essential for providing sufficient surface area for nutrient absorption. PMID:23989955

  13. Gut microbial communities of social bees.

    PubMed

    Kwong, Waldan K; Moran, Nancy A

    2016-06-01

    The gut microbiota can have profound effects on hosts, but the study of these relationships in humans is challenging. The specialized gut microbial community of honey bees is similar to the mammalian microbiota, as both are mostly composed of host-adapted, facultatively anaerobic and microaerophilic bacteria. However, the microbial community of the bee gut is far simpler than the mammalian microbiota, being dominated by only nine bacterial species clusters that are specific to bees and that are transmitted through social interactions between individuals. Recent developments, which include the discovery of extensive strain-level variation, evidence of protective and nutritional functions, and reports of eco-physiological or disease-associated perturbations to the microbial community, have drawn attention to the role of the microbiota in bee health and its potential as a model for studying the ecology and evolution of gut symbionts. PMID:27140688

  14. [Multiple Sclerosis and Commensal Gut Flora].

    PubMed

    Yamamura, Takashi

    2016-06-01

    Although a symbiotic relationship between commensal gut microbiota and host is widely appreciated, recent works have indicated that normal gut flora functions to prevent inflammatory bowel diseases and obesity in the host, indicating a more mutualistic relationship. Dysbiosis of the commensal flora may lead to development of these disorders. Studies using experimental auto immune encephalomyelitis (EAE), a rodent model for studying multiple sclerosis (MS), revealed that onset of MS may be triggered by dysbiosis in the gut. We recently revealed a significant reduction in certain clostridia strains, which probably function to induce regulatory T cells, in the gut microbiota of patients with MS. Results from this study should be consideved when designing strategies for the prevention and treatment of MS. PMID:27279159

  15. Effects of Antibiotics on Gut Microbiota.

    PubMed

    Lange, Kathleen; Buerger, Martin; Stallmach, Andreas; Bruns, Tony

    2016-01-01

    The gut microbiota influences essential human functions including digestion, energy metabolism, and inflammation by modulating multiple endocrine, neural, and immune pathways of the host. Its composition and complexity varies markedly across individuals and across different sites of the gut, but provides a certain level of resilience against external perturbation. Short-term antibiotic treatment is able to shift the gut microbiota to long-term alternative dysbiotic states, which may promote the development and aggravation of disease. Common features of post-antibiotic dysbiosis include a loss of taxonomic and functional diversity combined with reduced colonization resistance against invading pathogens, which harbors the danger of antimicrobial resistance. This review summarizes the antibiotic-related changes of the gut microbiota and potential consequences in health and disease. PMID:27028893

  16. Go with your gut: microbiota meet microglia

    PubMed Central

    Mosher, Kira Irving; Wyss-Coray, Tony

    2016-01-01

    Discovering the environmental factors that control microglia is key to understanding and managing brain health. A new study finds that microbiota in the gut are essential for regulating microglia maturation and activation. PMID:26108718

  17. Optogenetic pacing in Drosophila melanogaster

    PubMed Central

    Alex, Aneesh; Li, Airong; Tanzi, Rudolph E.; Zhou, Chao

    2015-01-01

    Electrical stimulation is currently the gold standard for cardiac pacing. However, it is invasive and nonspecific for cardiac tissues. We recently developed a noninvasive cardiac pacing technique using optogenetic tools, which are widely used in neuroscience. Optogenetic pacing of the heart provides high spatial and temporal precisions, is specific for cardiac tissues, avoids artifacts associated with electrical stimulation, and therefore promises to be a powerful tool in basic cardiac research. We demonstrated optogenetic control of heart rhythm in a well-established model organism, Drosophila melanogaster. We developed transgenic flies expressing a light-gated cation channel, channelrhodopsin-2 (ChR2), specifically in their hearts and demonstrated successful optogenetic pacing of ChR2-expressing Drosophila at different developmental stages, including the larva, pupa, and adult stages. A high-speed and ultrahigh-resolution optical coherence microscopy imaging system that is capable of providing images at a rate of 130 frames/s with axial and transverse resolutions of 1.5 and 3.9 μm, respectively, was used to noninvasively monitor Drosophila cardiac function and its response to pacing stimulation. The development of a noninvasive integrated optical pacing and imaging system provides a novel platform for performing research studies in developmental cardiology. PMID:26601299

  18. Leigh Syndrome in Drosophila melanogaster

    PubMed Central

    Da-Rè, Caterina; von Stockum, Sophia; Biscontin, Alberto; Millino, Caterina; Cisotto, Paola; Zordan, Mauro A.; Zeviani, Massimo; Bernardi, Paolo; De Pittà, Cristiano; Costa, Rodolfo

    2014-01-01

    Leigh Syndrome (LS) is the most common early-onset, progressive mitochondrial encephalopathy usually leading to early death. The single most prevalent cause of LS is occurrence of mutations in the SURF1 gene, and LSSurf1 patients show a ubiquitous and specific decrease in the activity of mitochondrial respiratory chain complex IV (cytochrome c oxidase, COX). SURF1 encodes an inner membrane mitochondrial protein involved in COX assembly. We established a Drosophila melanogaster model of LS based on the post-transcriptional silencing of CG9943, the Drosophila homolog of SURF1. Knockdown of Surf1 was induced ubiquitously in larvae and adults, which led to lethality; in the mesodermal derivatives, which led to pupal lethality; or in the central nervous system, which allowed survival. A biochemical characterization was carried out in knockdown individuals, which revealed that larvae unexpectedly displayed defects in all complexes of the mitochondrial respiratory chain and in the F-ATP synthase, while adults had a COX-selective impairment. Silencing of Surf1 expression in Drosophila S2R+ cells led to selective loss of COX activity associated with decreased oxygen consumption and respiratory reserve. We conclude that Surf1 is essential for COX activity and mitochondrial function in D. melanogaster, thus providing a new tool that may help clarify the pathogenic mechanisms of LS. PMID:25164807

  19. Insulin receptor in Drosophila melanogaster

    SciTech Connect

    Petruzzelli, L.; Herrera, R.; Rosen, O.

    1986-05-01

    A specific, high affinity insulin receptor is present in both adult Drosophila and in Drosophila embryos. Wheat germ lectin-enriched extracts of detergent-solubilized membranes from embryos and adults bind insulin with a K/sub d/ of 15 nM. Binding is specific for insulin; micromolar concentrations of proinsulin, IGFI, and IGFII are required to displace bound /sup 125/I-insulin. Insulin-dependent protein tyrosine kinase activity appears during embryogenesis. It is evident between 6 and 12 hours of development, peaks between 12 and 18 hours and falls in the adult. During 0-6 hours of embryogenesis, and in the adult, a specific protein band (Mr = 135,000) is crosslinked to /sup 125/I-insulin. During 6-12 and 12-18 hours of embryogenesis stages in which insulin-dependent protein tyrosine kinase is high, an additional band (Mr = 100,000) becomes crosslinked to /sup 125/I-insulin. Isolation and DNA sequence analysis of genomic clones encoding the Drosophila insulin receptor will be presented as will the characterization of insulin receptor mRNA's during development.

  20. 'Peer pressure' in larval Drosophila?

    PubMed

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

    2014-01-01

    Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila. PMID:24907371

  1. A Sall4 Mutant Mouse Model Useful for Studying the Role of Sall4 in Early Embryonic Development and Organogenesis

    PubMed Central

    Warren, Madhuri; Wang, Wei; Spiden, Sarah; Chen-Murchie, Dongrong; Tannahill, David; Steel, Karen P.; Bradley, Allan

    2008-01-01

    Summary SALL4 is a homologue of the Drosophila homeotic gene spalt, a zinc finger transcription factor, required for inner cell mass proliferation in early embryonic development. It also interacts with other transcription factors to control the development of the anorectal region, kidney, heart, limbs, and brain. Truncating mutations in SALL4 cause Okihiro syndrome, manifest as Duane anomaly, radial ray defects and sensorineural and conductive deafness. We report the characterization of a novel murine Sall4 null allele created by bacterial recombineering in ES cells. Homozygous mutant mice exhibit early embryonic lethality. Heterozygous mutant mice recapitulate phenotypic features of Okihiro syndrome including deafness, lower anogenital tract abnormalities, renal hypoplasia, anencephaly, Hirschprung’s disease, and skeletal defects. This phenotype shows important differences in cardiac and ear manifestations to previously characterized Sall4 mutant alleles and should prove useful for the investigation of the influence of modifier alleles and protein interactions on the transcriptional regulatory function of Sall4. PMID:17216607

  2. Gut-liver axis and sensing microbes.

    PubMed

    Szabo, Gyongyi; Bala, Shashi; Petrasek, Jan; Gattu, Arijeet

    2010-01-01

    'Detoxification' of gut-derived toxins and microbial products from gut-derived microbes is a major role of the liver. While the full repertoire of gut-derived microbial products that reach the liver in health and disease is yet to be explored, the levels of bacterial lipopolysaccharide (LPS), a component of Gram-negative bacteria, is increased in the portal and/or systemic circulation in several types of chronic liver diseases. Increased gut permeability and LPS play a role in alcoholic liver disease where alcohol impairs the gut epithelial integrity through alterations in tight junction proteins. In addition, non-alcoholic fatty liver disease is also associated with increased serum LPS levels and activation of the pro-inflammatory cascade plays a central role in disease progression. Microbial danger signals are recognized by pattern recognition receptors such as the Toll-like receptor 4 (TLR4). Increasing evidence suggests that TLR4-mediated signaling via the MyD88-dependent or MyD88-independent pathways may play different roles in liver diseases associated with increased LPS exposure of the liver as a result of gut permeability. For example, we showed that in alcoholic liver disease, the MyD88-independent, IRF3-dependent TLR4 cascade plays a role in steatosis and inflammation. Our recent data demonstrate that chronic alcohol exposure in the liver leads to sensitization of Kupffer cells to LPS via a mechanism involving upregulation of microRNA-155 in Kupffer cells. Thus, understanding the cell-specific recognition and intracellular signaling events in sensing gut-derived microbes will help to achieve an optimal balance in the gut-liver axis and ameliorate liver diseases. PMID:21525758

  3. Role of Gut Microbiota in Liver Disease.

    PubMed

    Brenner, David A; Paik, Yong-Han; Schnabl, Bernd

    2015-01-01

    Many lines of research have established a relationship between the gut microbiome and patients with liver disease. For example, patients with cirrhosis have increased bacteremia, increased blood levels of lipopolysaccharide, and increased intestinal permeability. Patients with cirrhosis have bacterial overgrowth in the small intestine. Selective intestinal decontamination with antibiotics is beneficial for patients with decompensated cirrhosis. In experimental models of chronic liver injury with fibrosis, several toll-like receptors (TLR) are required to make mice sensitive to liver fibrosis. The presumed ligand for the TLRs are bacterial products derived from the gut microbiome, and TLR knockout mice are resistant to liver inflammation and fibrosis. We and others have characterized the association between preclinical models of liver disease in mice with the microbial diversity in their gut microbiome. In each model, including intragastric alcohol, bile duct ligation, chronic carbon tetrachloride (CCl4), administration, and genetic obesity, there is a significant change in the gut microbiome from normal control mice. However, there is not a single clear bacterial strain or pattern that distinguish mice with liver injury from controlled mice. So how can the gut microbiota affect liver disease? We can identify at least 6 changes that would result in liver injury, inflammation, and/or fibrosis. These include: (1) changes in caloric yield of diet; (2) regulation of gut permeability to release bacterial products; (3) modulation of choline metabolism; (4) production of endogenous ethanol; (5) regulation of bile acid metabolism; and (6) regulation in lipid metabolism. PMID:26447960

  4. Seasonal Variation in Human Gut Microbiome Composition

    PubMed Central

    Davenport, Emily R.; Mizrahi-Man, Orna; Michelini, Katelyn; Barreiro, Luis B.; Ober, Carole; Gilad, Yoav

    2014-01-01

    The composition of the human gut microbiome is influenced by many environmental factors. Diet is thought to be one of the most important determinants, though we have limited understanding of the extent to which dietary fluctuations alter variation in the gut microbiome between individuals. In this study, we examined variation in gut microbiome composition between winter and summer over the course of one year in 60 members of a founder population, the Hutterites. Because of their communal lifestyle, Hutterite diets are similar across individuals and remarkably stable throughout the year, with the exception that fresh produce is primarily served during the summer and autumn months. Our data indicate that despite overall gut microbiome stability within individuals over time, there are consistent and significant population-wide shifts in microbiome composition across seasons. We found seasonal differences in both (i) the abundance of particular taxa (false discovery rate <0.05), including highly abundant phyla Bacteroidetes and Firmicutes, and (ii) overall gut microbiome diversity (by Shannon diversity; P = 0.001). It is likely that the dietary fluctuations between seasons with respect to produce availability explain, at least in part, these differences in microbiome composition. For example, high levels of produce containing complex carbohydrates consumed during the summer months might explain increased abundance of Bacteroidetes, which contain complex carbohydrate digesters, and decreased levels of Actinobacteria, which have been negatively correlated to fiber content in food questionnaires. Our observations demonstrate the plastic nature of the human gut microbiome in response to variation in diet. PMID:24618913

  5. The Gut Microbiome in the NOD Mouse.

    PubMed

    Peng, Jian; Hu, Youjia; Wong, F Susan; Wen, Li

    2016-01-01

    The microbiome (or microbiota) are an ecological community of commensal, symbiotic, and pathogenic microorganisms that outnumber the cells of the human body tenfold. These microorganisms are most abundant in the gut where they play an important role in health and disease. Alteration of the homeostasis of the gut microbiota can have beneficial or harmful consequences to health. There has recently been a major increase in studies on the association of the gut microbiome composition with disease phenotypes.The nonobese diabetic (NOD) mouse is an excellent mouse model to study spontaneous type 1 diabetes development. We, and others, have reported that gut bacteria are critical modulators for type 1 diabetes development in genetically susceptible NOD mice.Here we present our standard protocol for gut microbiome analysis in NOD mice that has been routinely implemented in our research laboratory. This incorporates the following steps: (1) Isolation of total DNA from gut bacteria from mouse fecal samples or intestinal contents; (2) bacterial DNA sequencing, and (3) basic data analysis. PMID:27032947

  6. Microbiota and the gut-brain axis.

    PubMed

    Bienenstock, John; Kunze, Wolfgang; Forsythe, Paul

    2015-08-01

    Changes in gut microbiota can modulate the peripheral and central nervous systems, resulting in altered brain functioning, and suggesting the existence of a microbiota gut-brain axis. Diet can also change the profile of gut microbiota and, thereby, behavior. Effects of bacteria on the nervous system cannot be disassociated from effects on the immune system since the two are in constant bidirectional communication. While the composition of the gut microbiota varies greatly among individuals, alterations to the balance and content of common gut microbes may affect the production of molecules such as neurotransmitters, e.g., gamma amino butyric acid, and the products of fermentation, e.g., the short chain fatty acids butyrate, propionate, and acetate. Short chain fatty acids, which are pleomorphic, especially butyrate, positively influence host metabolism by promoting glucose and energy homeostasis, regulating immune responses and epithelial cell growth, and promoting the functioning of the central and peripheral nervous systems. In the future, the composition, diversity, and function of specific probiotics, coupled with similar, more detailed knowledge about gut microbiota, will potentially help in developing more effective diet- and drug-based therapies. PMID:26175487

  7. Gut microbiota in autism and mood disorders

    PubMed Central

    Mangiola, Francesca; Ianiro, Gianluca; Franceschi, Francesco; Fagiuoli, Stefano; Gasbarrini, Giovanni; Gasbarrini, Antonio

    2016-01-01

    The hypothesis of an important role of gut microbiota in the maintenance of physiological state into the gastrointestinal (GI) system is supported by several studies that have shown a qualitative and quantitative alteration of the intestinal flora in a number of gastrointestinal and extra-gastrointestinal diseases. In the last few years, the importance of gut microbiota impairment in the etiopathogenesis of pathology such as autism, dementia and mood disorder, has been raised. The evidence of the inflammatory state alteration, highlighted in disorders such as schizophrenia, major depressive disorder and bipolar disorder, strongly recalls the microbiota alteration, highly suggesting an important role of the alteration of GI system also in neuropsychiatric disorders. Up to now, available evidences display that the impairment of gut microbiota plays a key role in the development of autism and mood disorders. The application of therapeutic modulators of gut microbiota to autism and mood disorders has been experienced only in experimental settings to date, with few but promising results. A deeper assessment of the role of gut microbiota in the development of autism spectrum disorder (ASD), as well as the advancement of the therapeutic armamentarium for the modulation of gut microbiota is warranted for a better management of ASD and mood disorders. PMID:26755882

  8. [Why could gut microbiota become a medication?].

    PubMed

    Bourlioux, P; Megerlin, F; Corthier, G; Gobert, J-G; Butel, M-J

    2014-09-01

    The gut microbiota (or gut flora) is a set of bacteria living in symbiosis with the host. Strictly associated with the intestinal tract and interacting with it, the gut microbiota is not a tissue nor an organ, but a supra-organism. A disruption of dialogue between bacteria and human cells is a risk factor or a possible cause of various diseases. The restoration of this dialogue, thanks to the transfer of the gut microbiota of a healthy individual to a patient whose balance of gut flora has been broken, is a new therapeutic approach. If its exact effect still eludes scientific understanding, its clinical benefit is well established for an indication, and is recently being tested for many others. The proven contribution of gut microbiota in the human physiological balance calls for intensifying research throughout the world about the state of knowledge and technologies, as well as on the legal and ethical dimension of fecal microbiota transfer. This didactic paper updates the questions in relation with this therapeutic act. PMID:25220228

  9. Probiotics, Prebiotics, and Synbiotics: Gut and Beyond

    PubMed Central

    Vyas, Usha; Ranganathan, Natarajan

    2012-01-01

    The human intestinal tract has been colonized by thousands of species of bacteria during the coevolution of man and microbes. Gut-borne microbes outnumber the total number of body tissue cells by a factor of ten. Recent metagenomic analysis of the human gut microbiota has revealed the presence of some 3.3 million genes, as compared to the mere 23 thousand genes present in the cells of the tissues in the entire human body. Evidence for various beneficial roles of the intestinal microbiota in human health and disease is expanding rapidly. Perturbation of the intestinal microbiota may lead to chronic diseases such as autoimmune diseases, colon cancers, gastric ulcers, cardiovascular disease, functional bowel diseases, and obesity. Restoration of the gut microbiota may be difficult to accomplish, but the use of probiotics has led to promising results in a large number of well-designed (clinical) studies. Microbiomics has spurred a dramatic increase in scientific, industrial, and public interest in probiotics and prebiotics as possible agents for gut microbiota management and control. Genomics and bioinformatics tools may allow us to establish mechanistic relationships among gut microbiota, health status, and the effects of drugs in the individual. This will hopefully provide perspectives for personalized gut microbiota management. PMID:23049548

  10. Regulatory elements mediating transcription from the Drosophila melanogaster actin 5C proximal promoter.

    PubMed Central

    Chung, Y T; Keller, E B

    1990-01-01

    The major cytoskeletal actin gene of Drosophila melanogaster, the actin 5C gene, has two promoters, the proximal one of which controls constitutive synthesis of actin in all growing tissues. To locate regulatory elements required for constitutive activity of the proximal promoter, mutants of this promoter were fused to the bacterial chloramphenicol acetyltransferase gene and assayed for transient expression activity in cultured Drosophila embryonic Schneider line 2 cells. An essential regulatory element has been located 313 base pairs upstream from the cap site. Deletion of this element lowered expression to one-third of the wild-type level. The element has the sequence AAGTTGTAGTTG, as shown by protein-binding footprinting with the reagent methidiumpropyl-EDTA-Fe(II). This element is probably not a general one, since it was not detected in a search of the published 5'-flanking sequences of 27 Drosophila genes. In addition to this regulatory element, there are five GAGA elements in the actin 5C proximal promoter, some or all of which are essential for the promoter activity as shown by an in vivo competition assay. Although this promoter has no classical TATA element, there is an essential promoter region about 35 base pairs upstream from the cap site that could be a TATA surrogate. The promoter also shows sequences homologous to the alcohol dehydrogenase factor 1-binding site and to the core of the vertebrate serum response element, but mutations of these sites did not affect promoter activity in transient expression assays. Images PMID:2104658

  11. Org-1-dependent lineage reprogramming generates the ventral longitudinal musculature of the Drosophila heart.

    PubMed

    Schaub, Christoph; März, Johannes; Reim, Ingolf; Frasch, Manfred

    2015-02-16

    Only few examples of transdifferentiation, which denotes the conversion of one differentiated cell type to another, are known to occur during normal development, and more often, it is associated with regeneration processes. With respect to muscles, dedifferentiation/redifferentiation processes have been documented during post-traumatic muscle regeneration in blastema of newts as well as during myocardial regeneration. As shown herein, the ventral longitudinal muscles of the adult Drosophila heart arise from specific larval alary muscles in a process that represents the first known example of syncytial muscle transdifferentiation via dedifferentiation into mononucleate myoblasts during normal development. We demonstrate that this unique process depends on the reinitiation of a transcriptional program previously employed for embryonic alary muscle development, in which the factors Org-1 (Drosophila Tbx1) and Tailup (Drosophila Islet1) are key components. During metamorphosis, the action of these factors is combined with cell-autonomous inputs from the ecdysone steroid and the Hox gene Ultrabithorax, which provide temporal and spatial specificity to the transdifferentiation events. Following muscle dedifferentiation, inductive cues, particularly from the remodeling heart tube, are required for the redifferentiation of myoblasts into ventral longitudinal muscles. Our results provide new insights into mechanisms of lineage commitment and cell-fate plasticity during development. PMID:25660543

  12. Evolution of Three Parent Genes and Their Retrogene Copies in Drosophila Species

    PubMed Central

    O'Neill, Ryan S.; Clark, Denise V.

    2013-01-01

    Retrogenes form a class of gene duplicate lacking the regulatory sequences found outside of the mRNA-coding regions of the parent gene. It is not clear how a retrogene's lack of parental regulatory sequences affects the evolution of the gene pair. To explore the evolution of parent genes and retrogenes, we investigated three such gene pairs in the family Drosophilidae; in Drosophila melanogaster, these gene pairs are CG8331 and CG4960, CG17734 and CG11825, and Sep2 and Sep5. We investigated the embryonic expression patterns of these gene pairs across multiple Drosophila species. Expression patterns of the parent genes and their single copy orthologs are relatively conserved across species, whether or not a species has a retrogene copy, although there is some variation in CG8331 and CG17734. In contrast, expression patterns of the retrogene orthologs have diversified. We used the genome sequences of 20 Drosophila species to investigate coding sequence evolution. The coding sequences of the three gene pairs appear to be evolving predominantly under negative selection; however, the parent genes and retrogenes show some distinct differences in amino acid sequence. Therefore, in general, retrogene expression patterns and coding sequences are distinct compared to their parents and, in some cases, retrogene expression patterns diversify. PMID:23841016

  13. Global analyses of mRNA translational control during early Drosophila embryogenesis

    PubMed Central

    Qin, Xiaoli; Ahn, Soyeon; Speed, Terence P; Rubin, Gerald M

    2007-01-01

    Background In many animals, the first few hours of life proceed with little or no transcription, and developmental regulation at these early stages is dependent on maternal cytoplasm rather than the zygotic nucleus. Translational control is critical for early Drosophila embryogenesis and is exerted mainly at the gene level. To understand post-transcriptional regulation during Drosophila early embryonic development, we used sucrose polysomal gradient analyses and GeneChip analysis to illustrate the translation profile of individual mRNAs. Results We determined ribosomal density and ribosomal occupancy of over 10,000 transcripts during the first ten hours after egg laying. Conclusion We report the extent and general nature of gene regulation at the translational level during early Drosophila embryogenesis on a genome-wide basis. The diversity of the translation profiles indicates multiple mechanisms modulating transcript-specific translation. Cluster analyses suggest that the genes involved in some biological processes are co-regulated at the translational level at certain developmental stages. PMID:17448252

  14. RNAi knockdown of Nopp140 induces Minute-like phenotypes in Drosophila.

    PubMed

    Cui, Zhengfang; DiMario, Patrick J

    2007-06-01

    Nopp140 associates with small nucleolar RNPs to chaperone pre-rRNA processing and ribosome assembly. Alternative splicing yields two isoforms in Drosophila: Nopp140-True is homologous to vertebrate Nopp140 particularly in its carboxy terminus, whereas Nopp140-RGG contains a glycine and arginine-rich (RGG) carboxy terminus typically found in vertebrate nucleolin. Loss of ribosome function or production at critical points in development leads to Minute phenotypes in Drosophila or the Treacher Collins syndrome (TCS) in humans. To ascertain the functional significance of Nopp140 in Drosophila development, we expressed interfering RNA using the GAL4/UAS system. Reverse transcription-PCR showed variable losses of Nopp140 mRNA in larvae from separate RNAi-expressing transgenic lines, whereas immunofluorescence microscopy with isoform-specific antibodies showed losses of Nopp140 in imaginal and polyploid tissues. Phenotypic expression correlated with the percent loss of Nopp140 transcripts: a >or=50% loss correlated with larval and pupal lethality, disrupted nuclear structures, and in some cases melanotic tumors, whereas a 30% loss correlated with adult wing, leg, and tergite deformities. We consider these adult phenotypes to be Minute-like and reminiscent of human craniofacial malformations associated with TCS. Similarly, overexpression of either isoform caused embryonic and larval lethality, thus indicating proper expression of Nopp140 is critical for normal development. PMID:17392509

  15. Genome-wide identification and developmental expression profiling of long noncoding RNAs during Drosophila metamorphosis.

    PubMed

    Chen, Bing; Zhang, Yi; Zhang, Xia; Jia, Shili; Chen, Shuang; Kang, Le

    2016-01-01

    An increasing number of long noncoding RNAs (lncRNAs) have been discovered with the recent advances in RNA-sequencing technologies. lncRNAs play key roles across diverse biological processes, and are involved in developmental regulation. However, knowledge about how the genome-wide expression of lncRNAs is developmentally regulated is still limited. We here performed a whole-genome identification of lncRNAs followed by a global expression profiling of these lncRNAs during development in Drosophila melanogaster. We combined bioinformatic prediction of lncRNAs with stringent filtering of protein-coding transcripts and experimental validation to define a high-confidence set of Drosophila lncRNAs. We identified 1,077 lncRNAs in the given transcriptomes that contain 43,967 transcripts; among these, 646 lncRNAs are novel. In vivo expression profiling of these lncRNAs in 27 developmental processes revealed that the expression of lncRNAs is highly temporally restricted relative to that of protein-coding genes. Remarkably, 21% and 42% lncRNAs were significantly upregulated at late embryonic and larval stage, the critical time for developmental transition. The results highlight the developmental specificity of lncRNA expression, and reflect the regulatory significance of a large subclass of lncRNAs for the onset of metamorphosis. The systematic annotation and expression analysis of lncRNAs during Drosophila development form the foundation for future functional exploration. PMID:26996731

  16. Neurl4 contributes to germ cell formation and integrity in Drosophila

    PubMed Central

    Jones, Jennifer; Macdonald, Paul M.

    2015-01-01

    ABSTRACT Primordial germ cells (PGCs) form at the posterior pole of the Drosophila embryo, and then migrate to their final destination in the gonad where they will produce eggs or sperm. Studies of the different stages in this process, including assembly of germ plasm in the oocyte during oogenesis, specification of a subset of syncytial embryonic nuclei as PGCs, and migration, have been informed by genetic analyses. Mutants have defined steps in the process, and the identities of the affected genes have suggested biochemical mechanisms. Here we describe a novel PGC phenotype. When Neurl4 activity is reduced, newly formed PGCs frequently adopt irregular shapes and appear to bud off vesicles. PGC number is also reduced, an effect exacerbated by a separate role for Neurl4 in germ plasm formation during oogenesis. Like its mammalian homolog, Drosophila Neurl4 protein is concentrated in centrosomes and downregulates centrosomal protein CP110. Reducing CP110 activity suppresses the abnormal PGC morphology of Neurl4 mutants. These results extend prior analyses of Neurl4 in cultured cells, revealing a heightened requirement for Neurl4 in germ-line cells in Drosophila. PMID:26116656

  17. Genome-wide identification and developmental expression profiling of long noncoding RNAs during Drosophila metamorphosis

    PubMed Central

    Chen, Bing; Zhang, Yi; Zhang, Xia; Jia, Shili; Chen, Shuang; Kang, Le

    2016-01-01

    An increasing number of long noncoding RNAs (lncRNAs) have been discovered with the recent advances in RNA-sequencing technologies. lncRNAs play key roles across diverse biological processes, and are involved in developmental regulation. However, knowledge about how the genome-wide expression of lncRNAs is developmentally regulated is still limited. We here performed a whole-genome identification of lncRNAs followed by a global expression profiling of these lncRNAs during development in Drosophila melanogaster. We combined bioinformatic prediction of lncRNAs with stringent filtering of protein-coding transcripts and experimental validation to define a high-confidence set of Drosophila lncRNAs. We identified 1,077 lncRNAs in the given transcriptomes that contain 43,967 transcripts; among these, 646 lncRNAs are novel. In vivo expression profiling of these lncRNAs in 27 developmental processes revealed that the expression of lncRNAs is highly temporally restricted relative to that of protein-coding genes. Remarkably, 21% and 42% lncRNAs were significantly upregulated at late embryonic and larval stage, the critical time for developmental transition. The results highlight the developmental specificity of lncRNA expression, and reflect the regulatory significance of a large subclass of lncRNAs for the onset of metamorphosis. The systematic annotation and expression analysis of lncRNAs during Drosophila development form the foundation for future functional exploration. PMID:26996731

  18. Expression of a Drosophila melanogaster acetylcholine receptor-related gene in the central nervous system

    SciTech Connect

    Wadsworth, S.C.; Rosenthal, L.S.; Kammermeyer, K.L.; Potter, M.B.; Nelson, D.J.

    1988-02-01

    The authors isolated Drosophila melanogaster genomic sequences with nucleotide and amino acid sequence homology to subunits of vertebrate acetylcholine receptor by hybridization with a Torpedo acetylcholine receptor subunit cDNA probe. Five introns are present in the portion of the Drosophila gene encoding the unprocessed protein and are positionally conserved relative to the human acetylcholine receptor alpha-subunit gene. The Drosophila genomic clone hybridized to salivary gland polytene chromosome 3L within region 64B and was termed AChR64B. A 3-kilobasae poly(A)-containing transcript complementary to the AChR64B clone was readily detectable by RNA blot hybridizations during midembryogenesis, during metamorphosis, and in newly enclosed adults. AChR64B transcripts were localized to the cellular regions of the central nervous system during embryonic, larval, pupal, and adult stages of development. During metamorphosis, a temporal relationship between the morphogenesis of the optic lobe and expression of AChR64B transcripts was observed.

  19. Biology and physiology of Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted wing drosophila, Drosophila suzukii, quickly emerged as a devastating invasive pest of small and stone fruits in the Americas and Europe. To better understand the population dynamics of D. suzukii, we reviewed recent work on juvenile development, adult reproduction, and seasonal variation in...

  20. Drosophila and Beer: An Experimental Laboratory Exercise

    ERIC Educational Resources Information Center

    Kurvink, Karen

    2004-01-01

    Drosophila melanogaster is a popular organism for studying genetics and development. Maintaining Drosophila on medium prepared with varying concentrations of beer and evaluating the effects on reproduction, life cycle stages and other factors is one of the exercises that is versatile and applicable to many student levels.

  1. Developmental angiogenesis: quail embryonic vasculature.

    PubMed

    Poole, T J; Coffin, J D

    1988-03-01

    We have examined the segregation and early morphogenesis of the embryonic vasculature by using a monoclonal antibody for immunofluorescence and by scanning electron microscopy. This antibody labels the presumptive endothelial cells (PECs) as they segregate from mesoderm. Similar embryos prepared for SEM revealed finer details of how these segregated cells interact to form the rudiments of the major blood vessels. Here we concentrate on the development of the dorsal aortae and the posterior cardinal veins. The dorsal aortae form from single PECs which segregate from the lateral mesoderm and aggregate into a loose cord ventral to the somites. These cells become more closely associated and a lumen forms. The posterior cardinal veins form from a loose plexus of cells segregated from the lateral mesoderm on its dorsal surface. These cells become intimately associated with the Wolffian ducts. PMID:3285464

  2. Undifferentiated Embryonal Sarcoma of Liver

    PubMed Central

    Kallam, Avyakta; Krishnamurthy, Jairam; Kozel, Jessica

    2015-01-01

    Undifferentiated embryonal sarcoma of the liver (UESL) is a rare malignant hepatic tumor. A 47 year old male presented with symptoms of sour taste in his mouth, occasional nausea, indigestion and 15-pound weight loss over two months. He had an unremarkable upper gastrointestinal endoscopy. Imaging showed a large liver mass in the left hepatic lobe that was resected and then reported as UESL. He went on to develop lung metastases and was initially treated with doxorubicin and ifosfamide followed by switching of therapy to gemcitabine and docetaxel due to progression of disease. He had a good response after two cycles and went on to receive four more cycles, achieving stable disease. We can therefore conclude that the combination of gemcitabine and docetaxel is a potential therapeutic option for patients with UESL. PMID:26788276

  3. Infrared inhibition of embryonic hearts

    NASA Astrophysics Data System (ADS)

    Wang, Yves T.; Rollins, Andrew M.; Jenkins, Michael W.

    2016-06-01

    Infrared control is a new technique that uses pulsed infrared lasers to thermally alter electrical activity. Originally developed for nerves, we have applied this technology to embryonic hearts using a quail model, previously demonstrating infrared stimulation and, here, infrared inhibition. Infrared inhibition enables repeatable and reversible block, stopping cardiac contractions for several seconds. Normal beating resumes after the laser is turned off. The block can be spatially specific, affecting propagation on the ventricle or initiation on the atrium. Optical mapping showed that the block affects action potentials and not just calcium or contraction. Increased resting intracellular calcium was observed after a 30-s exposure to the inhibition laser, which likely resulted in reduced mechanical function. Further optimization of the laser illumination should reduce potential damage. Stopping cardiac contractions by disrupting electrical activity with infrared inhibition has the potential to be a powerful tool for studying the developing heart.

  4. Undifferentiated Embryonal Sarcoma of Liver.

    PubMed

    Kallam, Avyakta; Krishnamurthy, Jairam; Kozel, Jessica; Shonka, Nicole

    2015-12-29

    Undifferentiated embryonal sarcoma of the liver (UESL) is a rare malignant hepatic tumor. A 47 year old male presented with symptoms of sour taste in his mouth, occasional nausea, indigestion and 15-pound weight loss over two months. He had an unremarkable upper gastrointestinal endoscopy. Imaging showed a large liver mass in the left hepatic lobe that was resected and then reported as UESL. He went on to develop lung metastases and was initially treated with doxorubicin and ifosfamide followed by switching of therapy to gemcitabine and docetaxel due to progression of disease. He had a good response after two cycles and went on to receive four more cycles, achieving stable disease. We can therefore conclude that the combination of gemcitabine and docetaxel is a potential therapeutic option for patients with UESL. PMID:26788276

  5. Characterization and embryonic expression of four amphioxus Frizzled genes with important functions during early embryogenesis.

    PubMed

    Qian, Guanghui; Li, Guang; Chen, Xiaoying; Wang, Yiquan

    2013-12-01

    The Wnt signaling pathway plays crucial roles in the embryonic patterning of all metazoans. Recent studies on Wnt genes in amphioxus have shed important insights into the evolution of the vertebrate Wnt gene family and their functions. Nevertheless, the potential roles of Wnt family receptors encoded by Frizzled (Fz) genes in amphioxus embryonic development remain to be investigated. In the present study, we identified four amphioxus Fz genes-AmphiFz1/2/7, AmphiFz4, AmphiFz5/8, and AmphiFz9/10-and analyzed their expression patterns during amphioxus embryogenesis. We found that these four Fz genes were maternally expressed and might be involved in early animal-vegetal axis establishment. The AmphiFz1/2/7 transcripts were detected in the central dorsal neural plate, mesoderm, the Hatschek's pit, and rim of the mouth, whereas those of AmphiFz4 were detected in the mesoderm, pharyngeal endoderm, and entire gut region. AmphiFz5/8 was exclusively expressed in the anterior-most region, whereas AmphiFz9/10 was expressed in the neural plate, somites, and tail bud. The dynamic and diverse expression patterns of amphioxus Fz genes suggest that these genes are not only associated with early embryonic axis establishment but also are involved in the development of several organs in amphioxus. PMID:24012522

  6. It's a gut feeling: how the gut microbiota affects the state of mind.

    PubMed

    Farmer, Adam D; Randall, Holly A; Aziz, Qasim

    2014-07-15

    Common human experience shows that stress and anxiety may modulate gut function. Such observations have been combined with an increasing evidence base that has culminated in the concept of the brain-gut axis. Nevertheless, it has not been until recently that the gut and its attendant components have been considered to influence higher cerebral function and behaviour per se. Moreover, the proposal that the gut and the bacteria contained therein (collectively referred to as the microbiota) can modulate mood and behaviours, has an increasing body of supporting evidence, albeit largely derived from animal studies. The gut microbiota is a dynamic and diverse ecosystem and forms a symbiotic relationship with the host. Herein we describe the components of the gut microbiota and mechanisms by which it can influence neural development, complex behaviours and nociception. Furthermore, we propose the novel concept of a 'state of gut' rather than a state of mind, particularly in relation to functional bowel disorders. Finally, we address the exciting possibility that the gut microbiota may offer a novel area of therapeutic intervention across a diverse array of both affective and gastrointestinal disorders. PMID:24665099

  7. Immunology of Gut Mucosal Vaccines

    PubMed Central

    Pasetti, Marcela F.; Simon, Jakub K.; Sztein, Marcelo B.; Levine, Myron M.

    2011-01-01

    Summary Understanding the mechanisms underlying the induction of immunity in the gastrointestinal mucosa following oral immunization and the cross-talk between mucosal and systemic immunity should expedite the development of vaccines to diminish the global burden caused by enteric pathogens. Identifying an immunological correlate of protection in the course of field trials of efficacy, animal models (when available), or human challenge studies is also invaluable. In industrialized country populations, live attenuated vaccines (e.g. polio, typhoid, and rotavirus) mimic natural infection and generate robust protective immune responses. In contrast, a major challenge is to understand and overcome the barriers responsible for the diminished immunogenicity and efficacy of the same enteric vaccines in underprivileged populations in developing countries. Success in developing vaccines against some enteric pathogens has heretofore been elusive (e.g. Shigella). Different types of oral vaccines can selectively or inclusively elicit mucosal secretory immunoglobulin A and serum immunoglobulin G antibodies and a variety of cell-mediated immune responses. Areas of research that require acceleration include interaction between the gut innate immune system and the stimulation of adaptive immunity, development of safe yet effective mucosal adjuvants, better understanding of homing to the mucosa of immunologically relevant cells, and elicitation of mucosal immunologic memory. This review dissects the immune responses elicited in humans by enteric vaccines. PMID:21198669

  8. Gut microbiota, probiotics and diabetes

    PubMed Central

    2014-01-01

    Diabetes is a condition of multifactorial origin, involving several molecular mechanisms related to the intestinal microbiota for its development. In type 2 diabetes, receptor activation and recognition by microorganisms from the intestinal lumen may trigger inflammatory responses, inducing the phosphorylation of serine residues in insulin receptor substrate-1, reducing insulin sensitivity. In type 1 diabetes, the lowered expression of adhesion proteins within the intestinal epithelium favours a greater immune response that may result in destruction of pancreatic β cells by CD8+ T-lymphocytes, and increased expression of interleukin-17, related to autoimmunity. Research in animal models and humans has hypothesized whether the administration of probiotics may improve the prognosis of diabetes through modulation of gut microbiota. We have shown in this review that a large body of evidence suggests probiotics reduce the inflammatory response and oxidative stress, as well as increase the expression of adhesion proteins within the intestinal epithelium, reducing intestinal permeability. Such effects increase insulin sensitivity and reduce autoimmune response. However, further investigations are required to clarify whether the administration of probiotics can be efficiently used for the prevention and management of diabetes. PMID:24939063

  9. 28. Embryonic and adult stem cell therapy.

    PubMed

    Henningson, Carl T; Stanislaus, Marisha A; Gewirtz, Alan M

    2003-02-01

    Stem cells are characterized by the ability to remain undifferentiated and to self-renew. Embryonic stem cells derived from blastocysts are pluripotent (able to differentiate into many cell types). Adult stem cells, which were traditionally thought to be monopotent multipotent, or tissue restricted, have recently also been shown to have pluripotent properties. Adult bone marrow stem cells have been shown to be capable of differentiating into skeletal muscle, brain microglia and astroglia, and hepatocytes. Stem cell lines derived from both embryonic stem and embryonic germ cells (from the embryonic gonadal ridge) are pluripotent and capable of self-renewal for long periods. Therefore embryonic stem and germ cells have been widely investigated for their potential to cure diseases by repairing or replacing damaged cells and tissues. Studies in animal models have shown that transplantation of fetal, embryonic stem, or embryonic germ cells may be able to treat some chronic diseases. In this review, we highlight recent developments in the use of stem cells as therapeutic agents for three such diseases: Diabetes, Parkinson disease, and congestive heart failure. We also discuss the potential use of stem cells as gene therapy delivery cells and the scientific and ethical issues that arise with the use of human stem cells. PMID:12592319

  10. Nonalcoholic Fatty Liver Disease and the Gut Microbiome.

    PubMed

    Boursier, Jerome; Diehl, Anna Mae

    2016-05-01

    Recent progress has allowed a more comprehensive study of the gut microbiota. Gut microbiota helps in health maintenance and gut dysbiosis associates with chronic metabolic diseases. Modulation of short-chain fatty acids and choline bioavailability, lipoprotein lipase induction, alteration of bile acid profile, endogenous alcohol production, or liver inflammation secondary to endotoxemia result from gut dysbiosis. Modulation of the gut microbiota by pre/probiotics gives promising results in animal, but needs to be evaluated in human before use in clinical practice. Gut microbiota adds complexity to the pathophysiology of nonalcoholic fatty liver disease but represents an opportunity to discover new therapeutic targets. PMID:27063268

  11. Convergence of gut microbiomes in myrmecophagous mammals.

    PubMed

    Delsuc, Frédéric; Metcalf, Jessica L; Wegener Parfrey, Laura; Song, Se Jin; González, Antonio; Knight, Rob

    2014-03-01

    Mammals have diversified into many dietary niches. Specialized myrmecophagous (ant- and termite-eating) placental mammals represent a textbook example of evolutionary convergence driven by extreme diet specialization. Armadillos, anteaters, aardvarks, pangolins and aardwolves thus provide a model system for understanding the potential role of gut microbiota in the convergent adaptation to myrmecophagy. Here, we expand upon previous mammalian gut microbiome studies by using high-throughput barcoded Illumina sequencing of the 16S rRNA gene to characterize the composition of gut microbiota in 15 species representing all placental myrmecophagous lineages and their close relatives from zoo- and field-collected samples. We confirm that both diet and phylogeny drive the evolution of mammalian gut microbiota, with cases of convergence in global composition, but also examples of phylogenetic inertia. Our results reveal specialized placental myrmecophages as a spectacular case of large-scale convergence in gut microbiome composition. Indeed, neighbour-net networks and beta-diversity plots based on UniFrac distances show significant clustering of myrmecophagous species (anteaters, aardvarks and aardwolves), even though they belong to phylogenetically distant lineages representing different orders. The aardwolf, which diverged from carnivorous hyenas only in the last 10 million years, experienced a convergent shift in the composition of its gut microbiome to become more similar to other myrmecophages. These results confirm diet adaptation to be a major driving factor of convergence in gut microbiome composition over evolutionary timescales. This study sets the scene for future metagenomic studies aiming at evaluating potential convergence in functional gene content in the microbiomes of specialized mammalian myrmecophages. PMID:24118574

  12. Circadian rhythms, alcohol and gut interactions

    PubMed Central

    Forsyth, Christopher B.; Voigt, Rbin M.; Burgess, Helen J.; Swanson, Garth R.; Keshavarzian, Ali

    2015-01-01

    The circadian clock establishes rhythms throughout the body with an approximately 24 hour period that affect expression of hundreds of genes. Epidemiological data reveal chronic circadian misalignment, common in our society, significantly increases the risk for a myriad of diseases, including cardiovascular disease, diabetes, cancer, infertility and gastrointestinal disease. Disruption of intestinal barrier function, also known as gut leakiness, is especially important in alcoholic liver disease (ALD). Several studies have shown that alcohol causes ALD in only a 20–30% subset of alcoholics. Thus, a better understanding is needed of why only a subset of alcoholics develops ALD. Compelling evidence shows that increased gut leakiness to microbial products and especially LPS play a critical role in the pathogenesis of ALD. Clock and other circadian clock genes have been shown to regulate lipid transport, motility and other gut functions. We hypothesized that one possible mechanism for alcohol-induced intestinal hyper-permeability is through disruption of central or peripheral (intestinal) circadian regulation. In support of this hypothesis, our recent data shows that disruption of circadian rhythms makes the gut more susceptible to injury. Our in vitro data show that alcohol stimulates increased Clock and Per2 circadian clock proteins and that siRNA knockdown of these proteins prevents alcohol-induced permeability. We also show that intestinal Cyp2e1-mediated oxidative stress is required for alcohol-induced upregulation of Clock and Per2 and intestinal hyperpermeability. Our mouse model of chronic alcohol feeding shows that circadian disruption through genetics (in ClockΔ19 mice) or environmental disruption by weekly 12h phase shifting results in gut leakiness alone and exacerbates alcohol-induced gut leakiness and liver pathology. Our data in human alcoholics show they exhibit abnormal melatonin profiles characteristic of circadian disruption. Taken together our

  13. Antioxidants Maintain E-Cadherin Levels to Limit Drosophila Prohemocyte Differentiation

    PubMed Central

    Gao, Hongjuan; Wu, Xiaorong; Simon, LaTonya; Fossett, Nancy

    2014-01-01

    Mitochondrial reactive oxygen species (ROS) regulate a variety of biological processes by networking with signal transduction pathways to maintain homeostasis and support adaptation to stress. In this capacity, ROS have been shown to promote the differentiation of progenitor cells, including mammalian embryonic and hematopoietic stem cells and Drosophila hematopoietic progenitors (prohemocytes). However, many questions remain about how ROS alter the regulatory machinery to promote progenitor differentiation. Here, we provide evidence for the hypothesis that ROS reduce E-cadherin levels to promote Drosophila prohemocyte differentiation. Specifically, we show that knockdown of the antioxidants, Superoxide dismutatase 2 and Catalase reduce E-cadherin protein levels prior to the loss of Odd-skipped-expressing prohemocytes. Additionally, over-expression of E-cadherin limits prohemocyte differentiation resulting from paraquat-induced oxidative stress. Furthermore, two established targets of ROS, Enhancer of Polycomb and FOS, control the level of E-cadherin protein expression. Finally, we show that knockdown of either Superoxide dismutatase 2 or Catalase leads to an increase in the E-cadherin repressor, Serpent. As a result, antioxidants and targets of ROS can control E-cadherin protein levels, and over-expression of E-cadherin can ameliorate the prohemocyte response to oxidative stress. Collectively, these data strongly suggest that ROS promote differentiation by reducing E-cadherin levels. In mammalian systems, ROS promote embryonic stem cell differentiation, whereas E-cadherin blocks differentiation. However, it is not known if elevated ROS reduce E-cadherin to promote embryonic stem cell differentiation. Thus, our findings may have identified an important mechanism by which ROS promote stem/progenitor cell differentiation. PMID:25226030

  14. Role of microglia in embryonic neurogenesis

    PubMed Central

    Tong, Chih Kong

    2016-01-01

    Microglia begin colonizing the developing brain as early as embryonic day 9, prior to the emergence of neurons and other glia. Their ontogeny is also distinct from other central nervous system cells, as they derive from yolk sac hematopoietic progenitors and not neural progenitors. In this review, we feature these unique characteristics of microglia and assess the spatiotemporal similarities between microglia colonization of the central nervous system and embryonic neurogenesis. We also infer to existing evidence for microglia function from embryonic through to postnatal neurodevelopment to postulate roles for microglia in neurogenesis. PMID:27555616

  15. Role of microglia in embryonic neurogenesis.

    PubMed

    Tong, Chih Kong; Vidyadaran, Sharmili

    2016-09-01

    Microglia begin colonizing the developing brain as early as embryonic day 9, prior to the emergence of neurons and other glia. Their ontogeny is also distinct from other central nervous system cells, as they derive from yolk sac hematopoietic progenitors and not neural progenitors. In this review, we feature these unique characteristics of microglia and assess the spatiotemporal similarities between microglia colonization of the central nervous system and embryonic neurogenesis. We also infer to existing evidence for microglia function from embryonic through to postnatal neurodevelopment to postulate roles for microglia in neurogenesis. PMID:27555616

  16. Phantom encodes the 25-hydroxylase of Drosophila melanogaster and Bombyx mori: a P450 enzyme critical in ecdysone biosynthesis.

    PubMed

    Warren, James T; Petryk, Anna; Marqués, Guillermo; Parvy, Jean-Philippe; Shinoda, Tetsuro; Itoyama, Kyo; Kobayashi, Jun; Jarcho, Michael; Li, Yutai; O'Connor, Michael B; Dauphin-Villemant, Chantal; Gilbert, Lawrence I

    2004-09-01

    We have reported recently the identification and characterization of the last three mitochondrial cytochrome P450 enzymes (CYP) controlling the biosynthesis of 20-hydroxyecdysone, the molting hormone of insects. These are encoded by the following genes: disembodied (dib, Cyp302a1, the 22-hydroxylase); shadow (sad, Cyp315a1, the 2-hydroxylase); and shade (shd, Cyp314a1, the 20-hydroxylase). Employing similar gene identification and transfection techniques and subsequent biochemical analysis of the expressed enzymatic activity, we report the identity of the Drosophila gene phantom (phm), located at 17D1 of the X chromosome, as encoding the microsomal 25-hydroxylase (Cyp306a1). Similar analysis following differential display-based gene identification has also resulted in the characterization of the corresponding 25-hydroxylase gene in Bombyx mori. Confirmation of 2,22,25-trideoxyecdysone (3beta,5beta-ketodiol) conversion to 2,22-dideoxyecdysone (3beta,5beta-ketotriol) mediated by either Phm enzyme employed LC, MS and definitive NMR analysis. In situ developmental gene analysis, in addition to northern, western and RT-PCR techniques during Drosophila embryonic, larval and adult development, are consistent with this identification. That is, strong expression of phm is restricted to the prothoracic gland cells of the Drosophila larval ring gland, where it undergoes dramatic changes in expression, and in the adult ovary, but also in the embryonic epidermis. During the last larval-larval transition in Bombyx, a similar expression pattern in the prothoracic gland is observed, but as in Drosophila, slight expression is also present in other tissues, suggesting a possible additional role for the phantom enzyme. PMID:15350618

  17. Peroxisomes in wild-type and rosy mutant Drosophila melanogaster.

    PubMed Central

    Beard, M E; Holtzman, E

    1987-01-01

    This study shows that peroxisomes are abundant in the Malpighian tubule and gut of wild-type Oregon R Drosophila melanogaster and that the peroxisomal population of the rosy-506 eye-color mutant differs from that of the wild type. Catalase activity in wild-type flies is demonstrable in bodies of appearance and centrifugal behavior comparable to the peroxisomes of vertebrate tissues. Xanthine oxidase (xanthine:oxygen oxidoreductase, EC 1.1.3.22) activity of the Malpighian tubule of wild-type flies is demonstrable cytochemically in bodies like those containing catalase. The rosy-506 mutant flies, with a deletion in the structural gene for xanthine dehydrogenase (xanthine:NAD+ oxidoreductase, EC 1.1.1.204), lack cytochemically demonstrable peroxisomal xanthine oxidase activity. In addition, peroxisomes in the rosy-506 mutants show less intense cytochemical staining for catalase than those in wild-type flies, and biochemical assays indicate that catalase in the rosy mutant is much more accessible to substrate in the absence of detergent than in the wild type. Thus, the rosy-506 mutation appears to affect peroxisomes and may mimic aspects of the defects of peroxisomes in some human metabolic disorders. Images PMID:3118368

  18. Intestinal inflammation and stem cell homeostasis in aging Drosophila melanogaster

    PubMed Central

    Ayyaz, Arshad; Jasper, Heinrich

    2013-01-01

    As a barrier epithelium, the intestinal epithelium has to coordinate physiological functions like digestion and nutrient resorption with the control of commensal bacteria and the prevention of pathogenic infections. It can therefore mount powerful innate immune and inflammatory responses, while, at the same time, maintaining tissue homeostasis through regenerative processes. How these different functions are coordinated remains unclear, and further insight is required to understand the age-related loss of homeostasis in this system, as well as the etiology of inflammatory and proliferative diseases of the gut. Recent work in Drosophila melanogaster has provided important new insight into the regulation of regenerative activity, innate immune homeostasis, commensal control, as well as age-related dysfunction in the intestine. Interestingly, many of the identified processes and mechanisms mirror similar homeostatic processes in the vertebrate intestine. This review summarized the current understanding of how innate immune responses, changes in commensal bacteria, and other challenges influence regenerative activity in the aging intestinal epithelium of flies and draws parallels to similar processes in mammals. PMID:24380076

  19. Global analysis of patterns of gene expression during Drosophila embryogenesis

    PubMed Central

    Tomancak, Pavel; Berman, Benjamin P; Beaton, Amy; Weiszmann, Richard; Kwan, Elaine; Hartenstein, Volker; Celniker, Susan E; Rubin, Gerald M

    2007-01-01

    Background Cell and tissue specific gene expression is a defining feature of embryonic development in multi-cellular organisms. However, the range of gene expression patterns, the extent of the correlation of expression with function, and the classes of genes whose spatial expression are tightly regulated have been unclear due to the lack of an unbiased, genome-wide survey of gene expression patterns. Results We determined and documented embryonic expression patterns for 6,003 (44%) of the 13,659 protein-coding genes identified in the Drosophila melanogaster genome with over 70,000 images and controlled vocabulary annotations. Individual expression patterns are extraordinarily diverse, but by supplementing qualitative in situ hybridization data with quantitative microarray time-course data using a hybrid clustering strategy, we identify groups of genes with similar expression. Of 4,496 genes with detectable expression in the embryo, 2,549 (57%) fall into 10 clusters representing broad expression patterns. The remaining 1,947 (43%) genes fall into 29 clusters representing restricted expression, 20% patterned as early as blastoderm, with the majority restricted to differentiated cell types, such as epithelia, nervous system, or muscle. We investigate the relationship between expression clusters and known molecular and cellular-physiological functions. Conclusion Nearly 60% of the genes with detectable expression exhibit broad patterns reflecting quantitative rather than qualitative differences between tissues. The other 40% show tissue-restricted expression; the expression patterns of over 1,500 of these genes are documented here for the first time. Within each of these categories, we identified clusters of genes associated with particular cellular and developmental functions. PMID:17645804

  20. Modulation of Morphogenesis by Egfr during Dorsal Closure in Drosophila

    PubMed Central

    Cormier, Olga; Cheng, David Chung-Pei; Reed, Bruce; Harden, Nicholas

    2013-01-01

    During Drosophila embryogenesis the process of dorsal closure (DC) results in continuity of the embryonic epidermis, and DC is well recognized as a model system for the analysis of epithelial morphogenesis as well as wound healing. During DC the flanking lateral epidermal sheets stretch, align, and fuse along the dorsal midline, thereby sealing a hole in the epidermis occupied by an extra-embryonic tissue known as the amnioserosa (AS). Successful DC requires the regulation of cell shape change via actomyosin contractility in both the epidermis and the AS, and this involves bidirectional communication between these two tissues. We previously demonstrated that transcriptional regulation of myosin from the zipper (zip) locus in both the epidermis and the AS involves the expression of Ack family tyrosine kinases in the AS in conjunction with Dpp secreted from the epidermis. A major function of Ack in other species, however, involves the negative regulation of Egfr. We have, therefore, asked what role Egfr might play in the regulation of DC. Our studies demonstrate that Egfr is required to negatively regulate epidermal expression of dpp during DC. Interestingly, we also find that Egfr signaling in the AS is required to repress zip expression in both the AS and the epidermis, and this may be generally restrictive to the progression of morphogenesis in these tissues. Consistent with this theme of restricting morphogenesis, it has previously been shown that programmed cell death of the AS is essential for proper DC, and we show that Egfr signaling also functions to inhibit or delay AS programmed cell death. Finally, we present evidence that Ack regulates zip expression by promoting the endocytosis of Egfr in the AS. We propose that the general role of Egfr signaling during DC is that of a braking mechanism on the overall progression of DC. PMID:23579691

  1. Ankrd6 is a mammalian functional homolog of Drosophila planar cell polarity gene diego and regulates coordinated cellular orientation in the mouse inner ear

    PubMed Central

    Jones, Chonnettia; Qian, Dong; Kim, Sun Myoung; Li, Shuangding; Ren, Dongdong; Knapp, Lindsey; Sprinzak, David; Avraham, Karen B.; Matsuzaki, Fumio; Chi, Fanglu; Chen, Ping

    2014-01-01

    The coordinated polarization of neighboring cells within the plane of the tissue, known as planar cell polarity (PCP), is a recurring theme in biology. It is required for numerous developmental processes for the form and function of many tissues and organs across species. The genetic pathway regulating PCP was first discovered in Drosophila, and an analogous but distinct pathway is emerging in vertebrates. It consists of membrane protein complexes known as core PCP proteins that are conserved across species. Here we report that the over-expression of the murine Ankrd6 (mAnkrd6) gene that shares homology with Drosophila core PCP gene diego causes a typical PCP phenotype in Drosophila, and mAnkrd6 can rescue the loss of function of diego in Drosophila. In mice, mAnkrd6 protein is asymmetrically localized in cells of the inner ear sensory organs, characteristic of components of conserved core PCP complexes. The loss of mAnkrd6 causes PCP defects in the inner ear sensory organs. Moreover, canonical Wnt signaling is significantly increased in mouse embryonic fibroblasts from mAnkrd6 knockout mice in comparison to wild type controls. Together, these results indicated that mAnkrd6 is a functional homolog of the Drosophila diego gene for mammalian PCP regulation and act to suppress canonical Wnt signaling. PMID:25218921

  2. Cryobiological preservation of Drosophila embryos

    SciTech Connect

    Mazur, P.; Schreuders, P.D.; Cole, K.W.; Hall, J.W. ); Mahowald, A.P. )

    1992-12-18

    The inability to cryobiologically preserve the fruit fly Drosophila melanogaster has required that fly stocks be maintained by frequent transfer of adults. This method is costly in terms of time and can lead to loss of stocks. Traditional slow freezing methods do not succeed because the embryos are highly sensitive to chilling. With the procedures described here, 68 percent of precisely staged 15-hour Oregon R (wild-type) embryos hatch after vitrification at -205[degree]C, and 40 percent of the resulting larvae develop into normal adult flies. These embryos are among the most complex organisms successfully preserved by cryobiology.

  3. Taste processing in Drosophila larvae

    PubMed Central

    Apostolopoulou, Anthi A.; Rist, Anna; Thum, Andreas S.

    2015-01-01

    The sense of taste allows animals to detect chemical substances in their environment to initiate appropriate behaviors: to find food or a mate, to avoid hostile environments and predators. Drosophila larvae are a promising model organism to study gustation. Their simple nervous system triggers stereotypic behavioral responses, and the coding of taste can be studied by genetic tools at the single cell level. This review briefly summarizes recent progress on how taste information is sensed and processed by larval cephalic and pharyngeal sense organs. The focus lies on several studies, which revealed cellular and molecular mechanisms required to process sugar, salt, and bitter substances. PMID:26528147

  4. Geotaxis baseline data for Drosophila

    NASA Technical Reports Server (NTRS)

    Schnebel, E. M.; Bhargava, R.; Grossfield, J.

    1987-01-01

    Geotaxis profiles for 20 Drosophila species and semispecies at different ages have been examined using a calibrated, adjustable slant board device. Measurements were taken at 5 deg intervals ranging from 0 deg to 85 deg. Clear strain and species differences are observed, with some groups tending to move upward (- geotaxis) with increasing angles, while others move downward (+ geotaxis). Geotactic responses change with age in some, but not all experimental groups. Sample geotaxis profiles are presented and their application to ecological and aging studies are discussed. Data provide a baseline for future evaluations of the biological effects of microgravity.

  5. The behaviour of Drosophila adult hindgut stem cells is controlled by Wnt and Hh signalling.

    PubMed

    Takashima, Shigeo; Mkrtchyan, Marianna; Younossi-Hartenstein, Amelia; Merriam, John R; Hartenstein, Volker

    2008-07-31

    The intestinal tract maintains proper function by replacing aged cells with freshly produced cells that arise from a population of self-renewing intestinal stem cells (ISCs). In the mammalian intestine, ISC self renewal, amplification and differentiation take place along the crypt-villus axis, and are controlled by the Wnt and hedgehog (Hh) signalling pathways. However, little is known about the mechanisms that specify ISCs within the developing intestinal epithelium, or about the signalling centres that help maintain them in their self-renewing stem cell state. Here we show that in adult Drosophila melanogaster, ISCs of the posterior intestine (hindgut) are confined to an anterior narrow segment, which we name the hindgut proliferation zone (HPZ). Within the HPZ, self renewal of ISCs, as well as subsequent proliferation and differentiation of ISC descendants, are controlled by locally emanating Wingless (Wg, a Drosophila Wnt homologue) and Hh signals. The anteriorly restricted expression of Wg in the HPZ acts as a niche signal that maintains cells in a slow-cycling, self-renewing mode. As cells divide and move posteriorly away from the Wg source, they enter a phase of rapid proliferation. During this phase, Hh signal is required for exiting the cell cycle and the onset of differentiation. The HPZ, with its characteristic proliferation dynamics and signalling properties, is set up during the embryonic phase and becomes active in the larva, where it generates all adult hindgut cells including ISCs. The mechanism and genetic control of cell renewal in the Drosophila HPZ exhibits a large degree of similarity with what is seen in the mammalian intestine. Our analysis of the Drosophila HPZ provides an insight into the specification and control of stem cells, highlighting the way in which the spatial pattern of signals that promote self renewal, growth and differentiation is set up within a genetically tractable model system. PMID:18633350

  6. Constrained Sypersymmetric Flipped SU (5) GUT Phenomenology

    SciTech Connect

    Ellis, John; Mustafayev, Azar; Olive, Keith A.; /Minnesota U., Theor. Phys. Inst. /Minnesota U. /Stanford U., Phys. Dept. /SLAC

    2011-08-12

    We explore the phenomenology of the minimal supersymmetric flipped SU(5) GUT model (CFSU(5)), whose soft supersymmetry-breaking (SSB) mass parameters are constrained to be universal at some input scale, Min, above the GUT scale, M{sub GUT}. We analyze the parameter space of CFSU(5) assuming that the lightest supersymmetric particle (LSP) provides the cosmological cold dark matter, paying careful attention to the matching of parameters at the GUT scale. We first display some specific examples of the evolutions of the SSB parameters that exhibit some generic features. Specifically, we note that the relationship between the masses of the lightest neutralino {chi} and the lighter stau {tilde {tau}}{sub 1} is sensitive to M{sub in}, as is the relationship between m{sub {chi}} and the masses of the heavier Higgs bosons A,H. For these reasons, prominent features in generic (m{sub 1/2}, m{sub 0}) planes such as coannihilation strips and rapid-annihilation funnels are also sensitive to Min, as we illustrate for several cases with tan {beta} = 10 and 55. However, these features do not necessarily disappear at large Min, unlike the case in the minimal conventional SU(5) GUT. Our results are relatively insensitive to neutrino masses.

  7. Gut Melatonin in Vertebrates: Chronobiology and Physiology

    PubMed Central

    Mukherjee, Sourav; Maitra, Saumen Kumar

    2015-01-01

    Melatonin, following discovery in the bovine pineal gland, has been detected in several extra-pineal sources including gastrointestinal tract or gut. Arylalkylamine N-acetyltransferase (AANAT) is the key regulator of its biosynthesis. Melatonin in pineal is rhythmically produced with a nocturnal peak in synchronization with environmental light–dark cycle. A recent study on carp reported first that melatonin levels and intensity of a ~23 kDa AANAT protein in each gut segment also exhibit significant daily variations but, unlike pineal, show a peak at midday in all seasons. Extensive experimental studies ruled out direct role of light–dark conditions in determining temporal pattern of gut melatoninergic system in carp, and opened up possible role of environmental non-photic cue(s) as its synchronizer. Based on mammalian findings, physiological significance of gut-derived melatonin also appears unique because its actions at local levels sharing paracrine and/or autocrine functions have been emphasized. The purpose of this mini review is to summarize the existing data on the chronobiology and physiology of gut melatonin and to emphasize their relation with the same hormone derived in the pineal in vertebrates including fish. PMID:26257705

  8. Gut/brain axis and the microbiota.

    PubMed

    Mayer, Emeran A; Tillisch, Kirsten; Gupta, Arpana

    2015-03-01

    Tremendous progress has been made in characterizing the bidirectional interactions between the central nervous system, the enteric nervous system, and the gastrointestinal tract. A series of provocative preclinical studies have suggested a prominent role for the gut microbiota in these gut-brain interactions. Based on studies using rodents raised in a germ-free environment, the gut microbiota appears to influence the development of emotional behavior, stress- and pain-modulation systems, and brain neurotransmitter systems. Additionally, microbiota perturbations by probiotics and antibiotics exert modulatory effects on some of these measures in adult animals. Current evidence suggests that multiple mechanisms, including endocrine and neurocrine pathways, may be involved in gut microbiota-to-brain signaling and that the brain can in turn alter microbial composition and behavior via the autonomic nervous system. Limited information is available on how these findings may translate to healthy humans or to disease states involving the brain or the gut/brain axis. Future research needs to focus on confirming that the rodent findings are translatable to human physiology and to diseases such as irritable bowel syndrome, autism, anxiety, depression, and Parkinson's disease. PMID:25689247

  9. Childhood Obesity: A Role for Gut Microbiota?

    PubMed Central

    Sanchez, Marina; Panahi, Shirin; Tremblay, Angelo

    2014-01-01

    Obesity is a serious public health issue affecting both children and adults. Prevention and management of obesity is proposed to begin in childhood when environmental factors exert a long-term effect on the risk for obesity in adulthood. Thus, identifying modifiable factors may help to reduce this risk. Recent evidence suggests that gut microbiota is involved in the control of body weight, energy homeostasis and inflammation and thus, plays a role in the pathophysiology of obesity. Prebiotics and probiotics are of interest because they have been shown to alter the composition of gut microbiota and to affect food intake and appetite, body weight and composition and metabolic functions through gastrointestinal pathways and modulation of the gut bacterial community. As shown in this review, prebiotics and probiotics have physiologic functions that contribute to changes in the composition of gut microbiota, maintenance of a healthy body weight and control of factors associated with childhood obesity through their effects on mechanisms controlling food intake, fat storage and alterations in gut microbiota. PMID:25546278

  10. The Gut Microbiota: Ecology and Function

    SciTech Connect

    Willing, B.P.; Jansson, J.K.

    2010-06-01

    The gastrointestinal (GI) tract is teeming with an extremely abundant and diverse microbial community. The members of this community have coevolved along with their hosts over millennia. Until recently, the gut ecosystem was viewed as black box with little knowledge of who or what was there or their specific functions. Over the past decade, however, this ecosystem has become one of fastest growing research areas of focus in microbial ecology and human and animal physiology. This increased interest is largely in response to studies tying microbes in the gut to important diseases afflicting modern society, including obesity, allergies, inflammatory bowel diseases, and diabetes. Although the importance of a resident community of microorganisms in health was first hypothesized by Pasteur over a century ago (Sears, 2005), the multiplicity of physiological changes induced by commensal bacteria has only recently been recognized (Hooper et al., 2001). The term 'ecological development' was recently coined to support the idea that development of the GI tract is a product of the genetics of the host and the host's interactions with resident microbes (Hooper, 2004). The search for new therapeutic targets and disease biomarkers has escalated the need to understand the identities and functions of the microorganisms inhabiting the gut. Recent studies have revealed new insights into the membership of the gut microbial community, interactions within that community, as well as mechanisms of interaction with the host. This chapter focuses on the microbial ecology of the gut, with an emphasis on information gleaned from recent molecular studies.

  11. The Gut Microbiome and the Brain

    PubMed Central

    Galland, Leo

    2014-01-01

    Abstract The human gut microbiome impacts human brain health in numerous ways: (1) Structural bacterial components such as lipopolysaccharides provide low-grade tonic stimulation of the innate immune system. Excessive stimulation due to bacterial dysbiosis, small intestinal bacterial overgrowth, or increased intestinal permeability may produce systemic and/or central nervous system inflammation. (2) Bacterial proteins may cross-react with human antigens to stimulate dysfunctional responses of the adaptive immune system. (3) Bacterial enzymes may produce neurotoxic metabolites such as D-lactic acid and ammonia. Even beneficial metabolites such as short-chain fatty acids may exert neurotoxicity. (4) Gut microbes can produce hormones and neurotransmitters that are identical to those produced by humans. Bacterial receptors for these hormones influence microbial growth and virulence. (5) Gut bacteria directly stimulate afferent neurons of the enteric nervous system to send signals to the brain via the vagus nerve. Through these varied mechanisms, gut microbes shape the architecture of sleep and stress reactivity of the hypothalamic-pituitary-adrenal axis. They influence memory, mood, and cognition and are clinically and therapeutically relevant to a range of disorders, including alcoholism, chronic fatigue syndrome, fibromyalgia, and restless legs syndrome. Their role in multiple sclerosis and the neurologic manifestations of celiac disease is being studied. Nutritional tools for altering the gut microbiome therapeutically include changes in diet, probiotics, and prebiotics. PMID:25402818

  12. Engineering the gut microbiota to treat hyperammonemia

    PubMed Central

    Shen, Ting-Chin David; Albenberg, Lindsey; Bittinger, Kyle; Chehoud, Christel; Chen, Ying-Yu; Judge, Colleen A.; Chau, Lillian; Ni, Josephine; Sheng, Michael; Lin, Andrew; Wilkins, Benjamin J.; Buza, Elizabeth L.; Lewis, James D.; Daikhin, Yevgeny; Nissim, Ilana; Yudkoff, Marc; Bushman, Frederic D.; Wu, Gary D.

    2015-01-01

    Increasing evidence indicates that the gut microbiota can be altered to ameliorate or prevent disease states, and engineering the gut microbiota to therapeutically modulate host metabolism is an emerging goal of microbiome research. In the intestine, bacterial urease converts host-derived urea to ammonia and carbon dioxide, contributing to hyperammonemia-associated neurotoxicity and encephalopathy in patients with liver disease. Here, we engineered murine gut microbiota to reduce urease activity. Animals were depleted of their preexisting gut microbiota and then inoculated with altered Schaedler flora (ASF), a defined consortium of 8 bacteria with minimal urease gene content. This protocol resulted in establishment of a persistent new community that promoted a long-term reduction in fecal urease activity and ammonia production. Moreover, in a murine model of hepatic injury, ASF transplantation was associated with decreased morbidity and mortality. These results provide proof of concept that inoculation of a prepared host with a defined gut microbiota can lead to durable metabolic changes with therapeutic utility. PMID:26098218

  13. Engineering the gut microbiota to treat hyperammonemia.

    PubMed

    Shen, Ting-Chin David; Albenberg, Lindsey; Bittinger, Kyle; Chehoud, Christel; Chen, Ying-Yu; Judge, Colleen A; Chau, Lillian; Ni, Josephine; Sheng, Michael; Lin, Andrew; Wilkins, Benjamin J; Buza, Elizabeth L; Lewis, James D; Daikhin, Yevgeny; Nissim, Ilana; Yudkoff, Marc; Bushman, Frederic D; Wu, Gary D

    2015-07-01

    Increasing evidence indicates that the gut microbiota can be altered to ameliorate or prevent disease states, and engineering the gut microbiota to therapeutically modulate host metabolism is an emerging goal of microbiome research. In the intestine, bacterial urease converts host-derived urea to ammonia and carbon dioxide, contributing to hyperammonemia-associated neurotoxicity and encephalopathy in patients with liver disease. Here, we engineered murine gut microbiota to reduce urease activity. Animals were depleted of their preexisting gut microbiota and then inoculated with altered Schaedler flora (ASF), a defined consortium of 8 bacteria with minimal urease gene content. This protocol resulted in establishment of a persistent new community that promoted a long-term reduction in fecal urease activity and ammonia production. Moreover, in a murine model of hepatic injury, ASF transplantation was associated with decreased morbidity and mortality. These results provide proof of concept that inoculation of a prepared host with a defined gut microbiota can lead to durable metabolic changes with therapeutic utility. PMID:26098218

  14. Host adaptive immunity alters gut microbiota.

    PubMed

    Zhang, Husen; Sparks, Joshua B; Karyala, Saikumar V; Settlage, Robert; Luo, Xin M

    2015-03-01

    It has long been recognized that the mammalian gut microbiota has a role in the development and activation of the host immune system. Much less is known on how host immunity regulates the gut microbiota. Here we investigated the role of adaptive immunity on the mouse distal gut microbial composition by sequencing 16 S rRNA genes from microbiota of immunodeficient Rag1(-/-) mice, versus wild-type mice, under the same housing environment. To detect possible interactions among immunological status, age and variability from anatomical sites, we analyzed samples from the cecum, colon, colonic mucus and feces before and after weaning. High-throughput sequencing showed that Firmicutes, Bacteroidetes and Verrucomicrobia dominated mouse gut bacterial communities. Rag1(-) mice had a distinct microbiota that was phylogenetically different from wild-type mice. In particular, the bacterium Akkermansia muciniphila was highly enriched in Rag1(-/-) mice compared with the wild type. This enrichment was suppressed when Rag1(-/-) mice received bone marrows from wild-type mice. The microbial community diversity increased with age, albeit the magnitude depended on Rag1 status. In addition, Rag1(-/-) mice had a higher gain in microbiota richness and evenness with increase in age compared with wild-type mice, possibly due to the lack of pressure from the adaptive immune system. Our results suggest that adaptive immunity has a pervasive role in regulating gut microbiota's composition and diversity. PMID:25216087

  15. Childhood obesity: a role for gut microbiota?

    PubMed

    Sanchez, Marina; Panahi, Shirin; Tremblay, Angelo

    2015-01-01

    Obesity is a serious public health issue affecting both children and adults. Prevention and management of obesity is proposed to begin in childhood when environmental factors exert a long-term effect on the risk for obesity in adulthood. Thus, identifying modifiable factors may help to reduce this risk. Recent evidence suggests that gut microbiota is involved in the control of body weight, energy homeostasis and inflammation and thus, plays a role in the pathophysiology of obesity. Prebiotics and probiotics are of interest because they have been shown to alter the composition of gut microbiota and to affect food intake and appetite, body weight and composition and metabolic functions through gastrointestinal pathways and modulation of the gut bacterial community. As shown in this review, prebiotics and probiotics have physiologic functions that contribute to changes in the composition of gut microbiota, maintenance of a healthy body weight and control of factors associated with childhood obesity through their effects on mechanisms controlling food intake, fat storage and alterations in gut microbiota. PMID:25546278

  16. The Oct1 homolog Nubbin is a repressor of NF-κB-dependent immune gene expression that increases the tolerance to gut microbiota

    PubMed Central

    2013-01-01

    Background Innate immune responses are evolutionarily conserved processes that provide crucial protection against invading organisms. Gene activation by potent NF-κB transcription factors is essential both in mammals and Drosophila during infection and stress challenges. If not strictly controlled, this potent defense system can activate autoimmune and inflammatory stress reactions, with deleterious consequences for the organism. Negative regulation to prevent gene activation in healthy organisms, in the presence of the commensal gut flora, is however not well understood. Results We show that the Drosophila homolog of mammalian Oct1/POU2F1 transcription factor, called Nubbin (Nub), is a repressor of NF-κB/Relish-driven antimicrobial peptide gene expression in flies. In nub1 mutants, which lack Nub-PD protein, excessive expression of antimicrobial peptide genes occurs in the absence of infection, leading to a significant reduction of the numbers of cultivatable gut commensal bacteria. This aberrant immune gene expression was effectively blocked by expression of Nub from a transgene. We have identified an upstream regulatory region, containing a cluster of octamer sites, which is required for repression of antimicrobial peptide gene expression in healthy flies. Chromatin immunoprecipitation experiments demonstrated that Nub binds to octamer-containing promoter fragments of several immune genes. Gene expression profiling revealed that Drosophila Nub negatively regulates many genes that are involved in immune and stress responses, while it is a positive regulator of genes involved in differentiation and metabolism. Conclusions This study demonstrates that a large number of genes that are activated by NF-κB/Relish in response to infection are normally repressed by the evolutionarily conserved Oct/POU transcription factor Nub. This prevents uncontrolled gene activation and supports the existence of a normal gut flora. We suggest that Nub protein plays an ancient role

  17. Sex difference in pathology of the ageing gut mediates the greater response of female lifespan to dietary restriction

    PubMed Central

    Regan, Jennifer C; Khericha, Mobina; Dobson, Adam J; Bolukbasi, Ekin; Rattanavirotkul, Nattaphong; Partridge, Linda

    2016-01-01

    Women live on average longer than men but have greater levels of late-life morbidity. We have uncovered a substantial sex difference in the pathology of the aging gut in Drosophila. The intestinal epithelium of the aging female undergoes major deterioration, driven by intestinal stem cell (ISC) division, while lower ISC activity in males associates with delay or absence of pathology, and better barrier function, even at old ages. Males succumb to intestinal challenges to which females are resistant, associated with fewer proliferating ISCs, suggesting a trade-off between highly active repair mechanisms and late-life pathology in females. Dietary restriction reduces gut pathology in aging females, and extends female lifespan more than male. By genetic sex reversal of a specific gut region, we induced female-like aging pathologies in males, associated with decreased lifespan, but also with a greater increase in longevity in response to dietary restriction. DOI: http://dx.doi.org/10.7554/eLife.10956.001 PMID:26878754

  18. Macrophages and cellular immunity in Drosophila melanogaster.

    PubMed

    Gold, Katrina S; Brückner, Katja

    2015-12-01

    The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. PMID:27117654

  19. Fertilization, syngamy, and early embryonic development in the cricket Gryllus bimaculatus (De Geer).

    PubMed

    Sato, Motoaki; Tanaka-Sato, Hikaru

    2002-12-01

    Fertilization and early embryonic mitoses of the cricket Gryllus bimaculatus were examined by fluorescence staining of whole-mount as well as squash preparations. Egg meiosis occurs near the ventral surface of the egg, while sperm transforms into a sperm pronucleus in the cytoplasmic island on the dorsal side. After meiosis, the egg pronucleus moves across the egg toward the sperm pronucleus in the island, where union of these nuclei occurs. The first cleavage mitosis is gonomeric, as in insects such as Pyrrhocoris, Drosophila, and Bombyx. After the third cleavage the synchrony of nuclear division is lost and the dividing nuclei are distributed all over the egg by 12 h after deposition. PMID:12386897

  20. Diminution of the gut resistome after a gut microbiota-targeted dietary intervention in obese children

    PubMed Central

    Wu, Guojun; Zhang, Chenhong; Wang, Jing; Zhang, Feng; Wang, Ruirui; Shen, Jian; Wang, Linghua; Pang, Xiaoyan; Zhang, Xiaojun; Zhao, Liping; Zhang, Menghui

    2016-01-01

    The gut microbiome represents an important reservoir of antibiotic resistance genes (ARGs). Effective methods are urgently needed for managing the gut resistome to fight against the antibiotic resistance threat. In this study, we show that a gut microbiota-targeted dietary intervention, which shifts the dominant fermentation of gut bacteria from protein to carbohydrate, significantly diminished the gut resistome and alleviated metabolic syndrome in obese children. Of the non-redundant metagenomic gene catalog of ~2 × 106 microbial genes, 399 ARGs were identified in 131 gene types and conferred resistance to 47 antibiotics. Both the richness and diversity of the gut resistome were significantly reduced after the intervention. A total of 201 of the 399 ARGs were carried in 120 co-abundance gene groups (CAGs) directly binned from the gene catalog across both pre-and post-intervention samples. The intervention significantly reduced several CAGs in Klebsiella, Enterobacter and Escherichia, which were the major hubs for multiple resistance gene types. Thus, dietary intervention may become a potentially effective method for diminishing the gut resistome. PMID:27044409

  1. It's a gut feeling: How the gut microbiota affects the state of mind

    PubMed Central

    Farmer, Adam D; Randall, Holly A; Aziz, Qasim

    2014-01-01

    Common human experience shows that stress and anxiety may modulate gut function. Such observations have been combined with an increasing evidence base that has culminated in the concept of the brain–gut axis. Nevertheless, it has not been until recently that the gut and its attendant components have been considered to influence higher cerebral function and behaviour per se. Moreover, the proposal that the gut and the bacteria contained therein (collectively referred to as the microbiota) can modulate mood and behaviours, has an increasing body of supporting evidence, albeit largely derived from animal studies. The gut microbiota is a dynamic and diverse ecosystem and forms a symbiotic relationship with the host. Herein we describe the components of the gut microbiota and mechanisms by which it can influence neural development, complex behaviours and nociception. Furthermore, we propose the novel concept of a ‘state of gut’ rather than a state of mind, particularly in relation to functional bowel disorders. Finally, we address the exciting possibility that the gut microbiota may offer a novel area of therapeutic intervention across a diverse array of both affective and gastrointestinal disorders. PMID:24665099

  2. Effect of Antibiotics on Gut Microbiota, Gut Hormones and Glucose Metabolism

    PubMed Central

    Mikkelsen, Kristian H.; Frost, Morten; Bahl, Martin I.; Licht, Tine R.; Jensen, Ulrich S.; Rosenberg, Jacob; Pedersen, Oluf; Hansen, Torben; Rehfeld, Jens F.; Holst, Jens J.; Vilsbøll, Tina; Knop, Filip K.

    2015-01-01

    Objective The gut microbiota has been designated as an active regulator of glucose metabolism and metabolic phenotype in a number of animal and human observational studies. We evaluated the effect of removing as many bacteria as possible by antibiotics on postprandial physiology in healthy humans. Methods Meal tests with measurements of postprandial glucose tolerance and postprandial release of insulin and gut hormones were performed before, immediately after and 6 weeks after a 4-day, broad-spectrum, per oral antibiotic cocktail (vancomycin 500 mg, gentamycin 40 mg and meropenem 500 mg once-daily) in a group of 12 lean and glucose tolerant males. Faecal samples were collected for culture-based assessment of changes in gut microbiota composition. Results Acute and dramatic reductions in the abundance of a representative set of gut bacteria was seen immediately following the antibiotic course, but no changes in postprandial glucose tolerance, insulin secretion or plasma lipid concentrations were found. Apart from an acute and reversible increase in peptide YY secretion, no changes were observed in postprandial gut hormone release. Conclusion As evaluated by selective cultivation of gut bacteria, a broad-spectrum 4-day antibiotics course with vancomycin, gentamycin and meropenem induced shifts in gut microbiota composition that had no clinically relevant short or long-term effects on metabolic variables in healthy glucose-tolerant males. Trial Registration clinicaltrials.gov NCT01633762 PMID:26562532

  3. Gut Bacteria May Hold Clues to Chronic Fatigue Syndrome

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159905.html Gut Bacteria May Hold Clues to Chronic Fatigue Syndrome Intestinal ... doctors -- may be influenced by a person's intestinal bacteria -- sometimes called gut microbiome, new research finds. "Patients ...

  4. Emerging Concepts on the Gut Microbiome and Multiple Sclerosis.

    PubMed

    Glenn, Justin D; Mowry, Ellen M

    2016-06-01

    Microbiota of the human body perform fundamental tasks that contribute to normal development, health, and homeostasis and are intimately associated with numerous organ systems, including the gut. Microbes begin gut inhabitance immediately following birth and promote proper gut epithelial construction and function, metabolism and nutrition, and immune system development. Inappropriate immune recognition of self-tissue can lead to autoimmune disease, including conditions such as multiple sclerosis (MS), in which the immune system recognizes and attacks central nervous system tissue. Preclinical studies have demonstrated a requirement of gut microbiota for neuroinflammatory autoimmune disease in animal models, and a growing number of clinical investigations are finding associations between MS status and the composition of the gut microbiota. In this review, we examine current undertakings into better understanding the role of gut bacteria and their phages in MS development, review associations of the gut microbiota makeup and MS, and discuss potential mechanisms by which the gut microbiota may be manipulated for therapeutic benefit. PMID:27145057

  5. Complete mitochondrial genome of Drosophila albomicans.

    PubMed

    Kang, Xiongbin; Luo, Xiao; Zhang, Zhi; Zhang, Zhen; Yang, Junqing; Bi, Guiqi

    2016-09-01

    Drosophila albomicans has been widely used as an important animal model for chromosome evolution. In this study, the mitochondrial genome sequence of this species is determined and described for the first time. The mitochondrial genome (15 849 bp) encompasses two rRNA, 22 tRNA, and 13 protein-coding genes. Genome content and structure are similar to those reported from other Drosophila mitochondrial genomes. Phylogeny analysis indicates that D. albomicans have a closer genetic relationship with Drosophil aincompta and Drosophil alittoralis. This mitochondrial genome is potentially important for studying molecular evolution and conservation genetics in Drosophila genus. PMID:26358579

  6. Cellular immune defenses of Drosophila melanogaster.

    PubMed

    Parsons, Brendon; Foley, Edan

    2016-05-01

    Drosophila melanogaster is a widely used model for the characterization of blood cell development and function, with an array of protocols for the manipulation and visualization of fixed or live cells in vitro or in vivo. Researchers have deployed these techniques to reveal Drosophila hemocytes as a remarkably versatile cell type that engulfs apoptotic corpses; neutralizes invading parasites; seals epithelial wounds; and deposits extracellular matrix proteins. In this review, we will discuss the key features of Drosophila hemocyte development and function, and identify similarities with vertebrate counterparts. PMID:26748247

  7. Drosophila Modeling of Heritable Neurodevelopmental Disorders

    PubMed Central

    Gatto, Cheryl L.; Broadie, Kendal

    2011-01-01

    Heritable neurodevelopmental disorders are multifaceted disease conditions encompassing a wide range of symptoms including intellectual disability, cognitive dysfunction, autism and myriad other behavioral impairments. In cases where single, causative genetic defects have been identified, such as Angelman syndrome, Rett syndrome, Neurofibromatosis Type 1 and Fragile X syndrome, the classical Drosophila genetic system has provided fruitful disease models. Recent Drosophila studies have advanced our understanding of UBE3A, MECP2, NF1 and FMR1 function, respectively, in genetic, biochemical, anatomical, physiological and behavioral contexts. Investigations in Drosophila continue to provide the essential mechanistic understanding required to facilitate the conception of rational therapeutic treatments. PMID:21596554

  8. Human genetics shape the gut microbiome

    PubMed Central

    Goodrich, Julia K.; Waters, Jillian L.; Poole, Angela C.; Sutter, Jessica L.; Koren, Omry; Blekhman, Ran; Beaumont, Michelle; Van Treuren, William; Knight, Rob; Bell, Jordana T.; Spector, Timothy D.; Clark, Andrew G.; Ley, Ruth E.

    2014-01-01

    Summary Host genetics and the gut microbiome can both influence metabolic phenotypes. However, whether host genetic variation shapes the gut microbiome and interacts with it to affect host phenotype is unclear. Here, we compared microbiotas across > 1,000 fecal samples obtained from the TwinsUK population, including 416 twin-pairs. We identified many microbial taxa whose abundances were influenced by host genetics. The most heritable taxon, the family Christensenellaceae, formed a cooccurrence network with other heritable Bacteria and with methanogenic Archaea. Furthermore, Christensenellaceae and its partners were enriched in individuals with low body mass index (BMI). An obese-associated microbiome was amended with Christensenella minuta, a cultured member of the Christensenellaceae, and transplanted to germfree mice. C. minuta amendment reduced weight gain and altered the microbiome of recipient mice. Our findings indicate that host genetics influence the composition of the human gut microbiome and can do so in ways that impact host metabolism. PMID:25417156

  9. Adenocarcinoma associated with tail gut cyst

    PubMed Central

    Wise, Susannah; Maloney-Patel, Nell; Rezac, Craig; Poplin, Elizabeth

    2013-01-01

    Primary adenocarcinomas of the presacral (retrorectal) space are rare. The diagnosis is usually delayed because of non-specific symptoms, and is made after a biopsy or surgery. These carcinomas arise from cystic lesions developing from remnants of the embryological postanal gut containing mucous-secreting epithelium, known as tail gut cysts. The potential for infection, perianal fistulas and most importantly, malignant change warrants an early complete surgical resection. From an oncologist’s perspective, the management of these carcinomas has varied, and has included adjuvant chemotherapy and/or radiation therapy. We describe here a rare case of adenocarcinoma associated with a tail gut cyst that was discovered incidentally and resected by a posterior approach (Kraske procedure). The patient has had clinical and periodic radiologic surveillance without any evidence of cancer recurrence for over a year and a half. PMID:23450681

  10. Metabolic tinkering by the gut microbiome

    PubMed Central

    Selkrig, Joel; Wong, Peiyan; Zhang, Xiaodong; Pettersson, Sven

    2014-01-01

    Brain development is an energy demanding process that relies heavily upon diet derived nutrients. Gut microbiota enhance the host’s ability to extract otherwise inaccessible energy from the diet via fermentation of complex oligosaccharides in the colon. This nutrient yield is estimated to contribute up to 10% of the host’s daily caloric requirement in humans and fluctuates in response to environmental variations. Research over the past decade has demonstrated a surprising role for the gut microbiome in normal brain development and function. In this review we postulate that perturbations in the gut microbial-derived nutrient supply, driven by environmental variation, profoundly impacts upon normal brain development and function. PMID:24685620

  11. Prebiotics as gut microflora management tools.

    PubMed

    Gibson, Glenn R

    2008-07-01

    Functional foods is an often-used term applied to dietary ingredients that serve to improve consumer health. Over the last few decades, these foods have gained in popularity with sales continuing to increase rapidly. Recent scientific, and some lay, reports have shown the popularity of both probiotics and prebiotics. These serve to elicit changes in the gut microbiota composition that increase populations of purported beneficial gut bacterial genera, for example, lactobacilli or bifidobacteria. Probiotics use live microbial feed additions, whereas prebiotics target indigenous flora components. As gastrointestinal disorders are prevalent in terms of human health, both probiotics and prebiotics serve an important role in the prophylactic management of various acute and chronic gut derived conditions. Examples include protection from gastroenteritis and some inflammatory conditions. PMID:18542038

  12. Rescue of Drosophila labial null mutant by the chicken ortholog Hoxb-1 demonstrates that the function of Hox genes is phylogenetically conserved.

    PubMed

    Lutz, B; Lu, H C; Eichele, G; Miller, D; Kaufman, T C

    1996-01-15

    Hox complexes are important players in the establishment of the body plan of invertebrates and vertebrates. Sequence comparison demonstrates a remarkable phylogenetic conservation of key structural features of Hox genes. The correlation between the physical order of genes along the chromosomes and their domains of function along the body axis is conserved between arthropods and vertebrates. Ectopic expression experiments suggest that the functions of homeo proteins also are conserved between invertebrates and vertebrates. However, it remains an open question whether vertebrate Hox genes expressed under the control of Drosophila regulatory sequences can substitute the function of Drosophila Hox genes. We have studied this issue with the Drosophila labial (lab) gene and its chicken ortholog gHoxb-1. We fused the entire protein-coding region of gHoxb-1 with previously identified regulatory sequences of lab. This approach places gHoxb-1 into the normal embryonic spatiotemporal context in which lab acts. Ten transgenic lines carrying gHoxb-1 were established and tested for their ability to rescue lab null mutant animals. Eight lines rescued with high efficiency, embryonic lethality, and abnormal head morphogenesis, two defects observed in lab null mutant embryos. The rescue with the gHoxb-1 minigene was close to the efficiency of that obtained with the Drosophila lab minigene. This indicates that gHoxb-1 protein can regulate lab target genes and thereby restore embryonic viability. This is striking, as Lab and gHoxb-1 proteins are divergent except for their homeo domains and a short stretch of amino acids amino-terminal to the homeo domain. Our findings demonstrate a functional conservation of the lab class homeo proteins between insects and vertebrates and support the view that function of Hox genes resides in relatively few conserved motifs and largely in the homeo domain. PMID:8566751

  13. Automated Tracking of Drosophila Specimens

    PubMed Central

    Chao, Rubén; Macía-Vázquez, Germán; Zalama, Eduardo; Gómez-García-Bermejo, Jaime; Perán, José-Ramón

    2015-01-01

    The fruit fly Drosophila Melanogaster has become a model organism in the study of neurobiology and behavior patterns. The analysis of the way the fly moves and its behavior is of great scientific interest for research on aspects such as drug tolerance, aggression or ageing in humans. In this article, a procedure for detecting, identifying and tracking numerous specimens of Drosophila by means of computer vision-based sensing systems is presented. This procedure allows dynamic information about each specimen to be collected at each moment, and then for its behavior to be quantitatively characterized. The proposed algorithm operates in three main steps: a pre-processing step, a detection and segmentation step, and tracking shape. The pre-processing and segmentation steps allow some limits of the image acquisition system and some visual artifacts (such as shadows and reflections) to be dealt with. The improvements introduced in the tracking step allow the problems corresponding to identity loss and swaps, caused by the interaction between individual flies, to be solved efficiently. Thus, a robust method that compares favorably to other existing methods is obtained. PMID:26258779

  14. Automated Tracking of Drosophila Specimens.

    PubMed

    Chao, Rubén; Macía-Vázquez, Germán; Zalama, Eduardo; Gómez-García-Bermejo, Jaime; Perán, José-Ramón

    2015-01-01

    The fruit fly Drosophila Melanogaster has become a model organism in the study of neurobiology and behavior patterns. The analysis of the way the fly moves and its behavior is of great scientific interest for research on aspects such as drug tolerance, aggression or ageing in humans. In this article, a procedure for detecting, identifying and tracking numerous specimens of Drosophila by means of computer vision-based sensing systems is presented. This procedure allows dynamic information about each specimen to be collected at each moment, and then for its behavior to be quantitatively characterized. The proposed algorithm operates in three main steps: a pre-processing step, a detection and segmentation step, and tracking shape. The pre-processing and segmentation steps allow some limits of the image acquisition system and some visual artifacts (such as shadows and reflections) to be dealt with. The improvements introduced in the tracking step allow the problems corresponding to identity loss and swaps, caused by the interaction between individual flies, to be solved efficiently. Thus, a robust method that compares favorably to other existing methods is obtained. PMID:26258779

  15. Drosophila Models of Cardiac Disease

    PubMed Central

    Piazza, Nicole; Wessells, R.J.

    2013-01-01

    The fruit fly Drosophila melanogaster has emerged as a useful model for cardiac diseases, both developmental abnormalities and adult functional impairment. Using the tools of both classical and molecular genetics, the study of the developing fly heart has been instrumental in identifying the major signaling events of cardiac field formation, cardiomyocyte specification, and the formation of the functioning heart tube. The larval stage of fly cardiac development has become an important model system for testing isolated preparations of living hearts for the effects of biological and pharmacological compounds on cardiac activity. Meanwhile, the recent development of effective techniques to study adult cardiac performance in the fly has opened new uses for the Drosophila model system. The fly system is now being used to study long-term alterations in adult performance caused by factors such as diet, exercise, and normal aging. The fly is a unique and valuable system for the study of such complex, long-term interactions, as it is the only invertebrate genetic model system with a working heart developmentally homologous to the vertebrate heart. Thus, the fly model combines the advantages of invertebrate genetics (such as large populations, facile molecular genetic techniques, and short lifespan) with physiological measurement techniques that allow meaningful comparisons with data from vertebrate model systems. As such, the fly model is well situated to make important contributions to the understanding of complicated interactions between environmental factors and genetics in the long-term regulation of cardiac performance. PMID:21377627

  16. Monoamines and sleep in Drosophila.

    PubMed

    Nall, Aleksandra; Sehgal, Amita

    2014-06-01

    Sleep is an important physiological state, but its function and regulation remain elusive. Drosophila melanogaster is a useful model organism for studying sleep because it has a well-established diurnal activity pattern, including consolidated periods of quiescence that share many characteristics with human sleep. Sleep behavior is regulated by circadian and homeostatic processes and is modulated by environmental and physiological context cues. These cues are communicated to sleep circuits by neurohormones and neuromodulators. A major class of neuromodulators, monoamines, has been found to be essential in various aspects of sleep regulation. Dopamine promotes arousal and sleep-dependent memory formation as well as daily activity. Octopamine, the insect homolog of norepinephrine, promotes wake and may play a role in circadian clock-dependent sleep and arousal. Serotonin promotes sleep and modulates circadian entrainment to light. The different monoamines each signal through multiple receptors in various brain regions in response to different conditions. How these separate circuits integrate their inputs into a single program of behavior is an open field of study for which Drosophila will continue to be a useful model. Monoamine biosynthetic pathways and receptors are conserved between flies and humans, and, thus far, their roles in modulating sleep also appear to be conserved. PMID:24886188

  17. Gut Microbiome and Kidney Disease in Pediatrics: Does Connection Exist?

    PubMed Central

    Vasylyeva, Tetyana L.; Singh, Ruchi

    2016-01-01

    Child development is a unique and continuous process that is impacted by genetics and environmental factors. Gut microbiome changes with development and depends on the stage of gut maturation, nutrition, and overall health. In spite of emerging data and active study in adults, the gut-renal axis in pediatrics has not been well considered and investigated. This review will focus on the current knowledge of gut microbiota impacts on kidney disease with extrapolation to the pediatric population. PMID:26973613

  18. Gut inflammation in chronic fatigue syndrome.

    PubMed

    Lakhan, Shaheen E; Kirchgessner, Annette

    2010-01-01

    Chronic fatigue syndrome (CFS) is a debilitating disease characterized by unexplained disabling fatigue and a combination of accompanying symptoms the pathology of which is incompletely understood. Many CFS patients complain of gut dysfunction. In fact, patients with CFS are more likely to report a previous diagnosis of irritable bowel syndrome (IBS), a common functional disorder of the gut, and experience IBS-related symptoms. Recently, evidence for interactions between the intestinal microbiota, mucosal barrier function, and the immune system have been shown to play a role in the disorder's pathogenesis.Studies examining the microecology of the gastrointestinal (GI) tract have identified specific microorganisms whose presence appears related to disease; in CFS, a role for altered intestinal microbiota in the pathogenesis of the disease has recently been suggested. Mucosal barrier dysfunction promoting bacterial translocation has also been observed. Finally, an altered mucosal immune system has been associated with the disease. In this article, we discuss the interplay between these factors in CFS and how they could play a significant role in GI dysfunction by modulating the activity of the enteric nervous system, the intrinsic innervation of the gut.If an altered intestinal microbiota, mucosal barrier dysfunction, and aberrant intestinal immunity contribute to the pathogenesis of CFS, therapeutic efforts to modify gut microbiota could be a means to modulate the development and/or progression of this disorder. For example, the administration of probiotics could alter the gut microbiota, improve mucosal barrier function, decrease pro-inflammatory cytokines, and have the potential to positively influence mood in patients where both emotional symptoms and inflammatory immune signals are elevated. Probiotics also have the potential to improve gut motility, which is dysfunctional in many CFS patients. PMID:20939923

  19. Insights from characterizing extinct human gut microbiomes.

    PubMed

    Tito, Raul Y; Knights, Dan; Metcalf, Jessica; Obregon-Tito, Alexandra J; Cleeland, Lauren; Najar, Fares; Roe, Bruce; Reinhard, Karl; Sobolik, Kristin; Belknap, Samuel; Foster, Morris; Spicer, Paul; Knight, Rob; Lewis, Cecil M

    2012-01-01

    In an effort to better understand the ancestral state of the human distal gut microbiome, we examine feces retrieved from archaeological contexts (coprolites). To accomplish this, we pyrosequenced the 16S rDNA V3 region from duplicate coprolite samples recovered from three archaeological sites, each representing a different depositional environment: Hinds Cave (~8000 years B.P.) in the southern United States, Caserones (1600 years B.P.) in northern Chile, and Rio Zape in northern Mexico (1400 years B.P.). Clustering algorithms grouped samples from the same site. Phyletic representation was more similar within sites than between them. A Bayesian approach to source-tracking was used to compare the coprolite data to published data from known sources that include, soil, compost, human gut from rural African children, human gut, oral and skin from US cosmopolitan adults and non-human primate gut. The data from the Hinds Cave samples largely represented unknown sources. The Caserones samples, retrieved directly from natural mummies, matched compost in high proportion. A substantial and robust proportion of Rio Zape data was predicted to match the gut microbiome found in traditional rural communities, with more minor matches to other sources. One of the Rio Zape samples had taxonomic representation consistent with a child. To provide an idealized scenario for sample preservation, we also applied source tracking to previously published data for Ötzi the Iceman and a soldier frozen for 93 years on a glacier. Overall these studies reveal that human microbiome data has been preserved in some coprolites, and these preserved human microbiomes match more closely to those from the rural communities than to those from cosmopolitan communities. These results suggest that the modern cosmopolitan lifestyle resulted in a dramatic change to the human gut microbiome. PMID:23251439

  20. Insights from Characterizing Extinct Human Gut Microbiomes

    PubMed Central

    Tito, Raul Y.; Knights, Dan; Metcalf, Jessica; Obregon-Tito, Alexandra J.; Cleeland, Lauren; Najar, Fares; Roe, Bruce; Reinhard, Karl; Sobolik, Kristin; Belknap, Samuel; Foster, Morris; Spicer, Paul; Knight, Rob; Lewis, Cecil M.

    2012-01-01

    In an effort to better understand the ancestral state of the human distal gut microbiome, we examine feces retrieved from archaeological contexts (coprolites). To accomplish this, we pyrosequenced the 16S rDNA V3 region from duplicate coprolite samples recovered from three archaeological sites, each representing a different depositional environment: Hinds Cave (∼8000 years B.P.) in the southern United States, Caserones (1600 years B.P.) in northern Chile, and Rio Zape in northern Mexico (1400 years B.P.). Clustering algorithms grouped samples from the same site. Phyletic representation was more similar within sites than between them. A Bayesian approach to source-tracking was used to compare the coprolite data to published data from known sources that include, soil, compost, human gut from rural African children, human gut, oral and skin from US cosmopolitan adults and non-human primate gut. The data from the Hinds Cave samples largely represented unknown sources. The Caserones samples, retrieved directly from natural mummies, matched compost in high proportion. A substantial and robust proportion of Rio Zape data was predicted to match the gut microbiome found in traditional rural communities, with more minor matches to other sources. One of the Rio Zape samples had taxonomic representation consistent with a child. To provide an idealized scenario for sample preservation, we also applied source tracking to previously published data for Ötzi the Iceman and a soldier frozen for 93 years on a glacier. Overall these studies reveal that human microbiome data has been preserved in some coprolites, and these preserved human microbiomes match more closely to those from the rural communities than to those from cosmopolitan communities. These results suggest that the modern cosmopolitan lifestyle resulted in a dramatic change to the human gut microbiome. PMID:23251439

  1. Cosmology of F-theory GUTs

    NASA Astrophysics Data System (ADS)

    Heckman, Jonathan J.; Tavanfar, Alireza; Vafa, Cumrun

    2010-04-01

    In this paper we study the interplay between the recently proposed F-theory GUTs and cosmology. Despite the fact that the parameter range for F-theory GUT models is very narrow, we find that F-theory GUTs beautifully satisfy most cosmological constraints without any further restrictions. The viability of the scenario hinges on the interplay between various components of the axion supermultiplet, which in F-theory GUTs is also responsible for breaking supersymmetry. In these models, the gravitino is the LSP and develops a mass by eating the axino mode. The radial component of the axion supermultiplet known as the saxion typically begins to oscillate in the early Universe, eventually coming to dominate the energy density. Its decay reheats the Universe to a temperature of ˜1GeV, igniting BBN and diluting all thermal relics such as the gravitino by a factor of ˜10-4 - 10-5 such that gravitinos contribute a sizable component of the dark matter. In certain cases, non-thermally produced relics such as the axion, or gravitinos generated from the decay of the saxion can also contribute to the abundance of dark matter. Remarkably enough, this cosmological scenario turns out to be independent of the initial reheating temperature of the Universe. This is due to the fact that the initial oscillation temperature of the saxion coincides with the freeze out temperature for gravitinos in F-theory GUTs. We also find that saxion dilution is compatible with generating the desired baryon asymmetry from standard leptogenesis. Finally, the gravitino mass range in F-theory GUTs is 10 - 100MeV, which interestingly coincides with the window of values required for the decay of the NLSP to solve the problem of 7 Li over-production.

  2. Schizophrenia and the gut-brain axis.

    PubMed

    Nemani, Katlyn; Hosseini Ghomi, Reza; McCormick, Beth; Fan, Xiaoduo

    2015-01-01

    Several risk factors for the development of schizophrenia can be linked through a common pathway in the intestinal tract. It is now increasingly recognized that bidirectional communication exists between the brain and the gut that uses neural, hormonal, and immunological routes. An increased incidence of gastrointestinal (GI) barrier dysfunction, food antigen sensitivity, inflammation, and the metabolic syndrome is seen in schizophrenia. These findings may be influenced by the composition of the gut microbiota. A significant subgroup of patients may benefit from the initiation of a gluten and casein-free diet. Antimicrobials and probiotics have therapeutic potential for reducing the metabolic dysfunction and immune dysregulation seen in patients with schizophrenia. PMID:25240858

  3. What is Obesity Doing to Your Gut?

    PubMed

    Lee, Yeong Yeh

    2015-01-01

    Obesity is a fast-emerging epidemic in the Asia-Pacific region, with numbers paralleling the rising global prevalence within the past 30 years. The landscape of gut diseases in Asia has been drastically changed by obesity. In addition to more non-specific abdominal symptoms, obesity is the cause of gastro-oesophageal reflux disease, various gastrointestinal cancers (colorectal cancer, hepatocellular carcinoma, oesophageal adenocarcinoma, gastric cardia adenocarcinoma, pancreatic cancer and gallbladder cancer) and non-alcoholic fatty liver disease. Abnormal cross-talk between the gut microbiome and the obese host seems to play a central role in the pathogenesis, but more studies are needed. PMID:25892944

  4. Differential and stage-related expression in embryonic tissues of a new human homoeobox gene.

    PubMed

    Mavilio, F; Simeone, A; Giampaolo, A; Faiella, A; Zappavigna, V; Acampora, D; Poiana, G; Russo, G; Peschle, C; Boncinelli, E

    The homoeobox is a 183 base-pair (bp) DNA sequence conserved in several Drosophila genes controlling segmentation and segment identity. Homoeobox sequences have been detected in the genome of species ranging from insects and anellids to vertebrates and homoeobox containing genes have been cloned from Xenopus, mouse and man. We recently isolated human homoeobox containing complementary DNA clones, that represent transcripts from four different human genes. One clone (HHO.c10) is selectively expressed in a 2.1 kilobase (kb) polyadenylated transcript in the spinal cord of human embryos and fetuses 5-10 weeks after fertilization. We report the characterization of a second cDNA clone, termed HHO.c13, that represents a new homoeobox gene. This clone encodes a protein of 255 amino-acid residues, which includes a pentapeptide, upstream of the homoeo domain, conserved in other Drosophila, Xenopus, murine and human homoeobox genes. By Northern analysis HHO.c13 detects multiple embryonic transcripts, which are differentially expressed in spinal cord, brain, backbone rudiments, limb buds and heart in 5-9-week-old human embryos and fetuses, in a striking organ- and stage-specific pattern. These observations suggest that in early mammalian development homoeobox genes may exert a wide spectrum of control functions in a variety of organs and body parts, in addition to the spinal cord. PMID:2879245

  5. Standard methods for research on apis mellifera gut symbionts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gut microbes can play an important role in digestion, disease resistance, and the general health of animals, but little is known about the biology of gut symbionts in Apis mellifera. This paper is part of a series on honey bee research methods, providing protocols for studying gut symbionts. We desc...

  6. Standard methods for research on Apis mellifera gut symbionts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gut microbes can play an important role in digestion, disease resistance, and the general health of animals, but little is known about the biology of gut symbionts in Apis mellifera. This paper is part of a series on honey bee research methods, providing protocols for studying gut symbionts. We desc...

  7. Functional roles of low calorie sweeteners on gut function.

    PubMed

    Meyer-Gerspach, A C; Wölnerhanssen, B; Beglinger, C

    2016-10-01

    This short review summarizes the effects of low calorie sweeteners (fructose, non-nutritive low calorie sweeteners) on gut functions focusing on the gut sweet taste receptor system. The effects of these molecules on secretion of gut peptides associated with glycemic homeostasis and appetite regulation is reviewed as well as effects on gastric emptying and glucose absorption. PMID:26861179

  8. The role of psychosocial factors in functional gut disease.

    PubMed

    Kamm, M A

    1998-01-01

    The link between psychological factors and functional gut disorders is indisputable. This review considers some of the mechanisms by which psychological state affect gut function, how these psychological factors and their effects on the gut might be measured, and how psychological treatments might benefit patients with functional disorders. PMID:10027671

  9. Drosophila embryos lacking N-myristoyltransferase have multiple developmental defects.

    PubMed

    Ntwasa, M; Aapies, S; Schiffmann, D A; Gay, N J

    2001-01-15

    Lipid modification of proteins by the addition of myristic acid to the N-terminal is important in a number of critical cellular processes, for example, signal transduction and the modulation of membrane association by myristoyl switches. Myristic acid is added to proteins by the enzyme N-myristoyltransferase (NMT) and in this paper we detail the effects on embryonic development of a null mutation in the Drosophila NMT gene. Mutant embryos display a range of phenotypes, including failures of head involution, dorsal closure, and germ-band retraction, morphogenetic processes that require cellular movements. Embryos with milder phenotypes have more specific defects in the central nervous system, including thinning of the ventral nerve chord and, in some embryos, specific scission at parasegment 10. Staining of mutant embryos with phalloidin shows that the mutant embryos have a disrupted actin cytoskeleton and abnormal cell morphology. These phenotypes are strikingly similar to those caused by genes involved in dynamic rearrangement of the actin cytoskeleton. For example the myristoylated nonreceptor tyrosine kinases Dsrc42A and Dsrc64B were shown recently to be key regulators of dorsal closure. In addition, analysis of cell death reveals widespread ectopic apoptosis. Our findings are consistent with the hypothesis that the myristoyl switches and signaling pathways characterized at the biochemical level have important functions in fundamental morphogenetic processes. PMID:11139338

  10. Neuropeptides Modulate Female Chemosensory Processing upon Mating in Drosophila

    PubMed Central

    Zhang, Mo; Loschek, Laura F.; Grunwald Kadow, Ilona C.

    2016-01-01

    A female’s reproductive state influences her perception of odors and tastes along with her changed behavioral state and physiological needs. The mechanism that modulates chemosensory processing, however, remains largely elusive. Using Drosophila, we have identified a behavioral, neuronal, and genetic mechanism that adapts the senses of smell and taste, the major modalities for food quality perception, to the physiological needs of a gravid female. Pungent smelling polyamines, such as putrescine and spermidine, are essential for cell proliferation, reproduction, and embryonic development in all animals. A polyamine-rich diet increases reproductive success in many species, including flies. Using a combination of behavioral analysis and in vivo physiology, we show that polyamine attraction is modulated in gravid females through a G-protein coupled receptor, the sex peptide receptor (SPR), and its neuropeptide ligands, MIPs (myoinhibitory peptides), which act directly in the polyamine-detecting olfactory and taste neurons. This modulation is triggered by an increase of SPR expression in chemosensory neurons, which is sufficient to convert virgin to mated female olfactory choice behavior. Together, our data show that neuropeptide-mediated modulation of peripheral chemosensory neurons increases a gravid female’s preference for important nutrients, thereby ensuring optimal conditions for her growing progeny. PMID:27145127

  11. Fasciclin II controls proneural gene expression in Drosophila.

    PubMed Central

    García-Alonso, L; VanBerkum, M F; Grenningloh, G; Schuster, C; Goodman, C S

    1995-01-01

    Fasciclin II (Fas II), an NCAM-like cell adhesion molecule in Drosophila, is expressed on a subset of embryonic axons and controls selective axon fasiculation. Fas II is also expressed in imaginal discs. Here we use genetic analysis to show that Fas II is required for the control of proneural gene expression. Clusters of cells in the eye-antennal imaginal disc express the achaete proneural gene and give rise to mechanosensory neurons; other clusters of cells express the atonal gene and give rise to ocellar photoreceptor neurons. In fasII loss-of-function mutants, the expression of both proneural genes is absent in certain locations, and, as a result, the corresponding sensory precursors fail to develop. In fasII gain-of-function conditions, extra sensory structures arise from this same region of the imaginal disc. Mutations in the Abelson tyrosine kinase gene show dominant interactions with fasII mutations, suggesting that Abl and Fas II function in a signaling pathway that controls proneural gene expression. Images Fig. 1 Fig. 2 PMID:7479828

  12. Neuropeptides Modulate Female Chemosensory Processing upon Mating in Drosophila.

    PubMed

    Hussain, Ashiq; Üçpunar, Habibe K; Zhang, Mo; Loschek, Laura F; Grunwald Kadow, Ilona C

    2016-05-01

    A female's reproductive state influences her perception of odors and tastes along with her changed behavioral state and physiological needs. The mechanism that modulates chemosensory processing, however, remains largely elusive. Using Drosophila, we have identified a behavioral, neuronal, and genetic mechanism that adapts the senses of smell and taste, the major modalities for food quality perception, to the physiological needs of a gravid female. Pungent smelling polyamines, such as putrescine and spermidine, are essential for cell proliferation, reproduction, and embryonic development in all animals. A polyamine-rich diet increases reproductive success in many species, including flies. Using a combination of behavioral analysis and in vivo physiology, we show that polyamine attraction is modulated in gravid females through a G-protein coupled receptor, the sex peptide receptor (SPR), and its neuropeptide ligands, MIPs (myoinhibitory peptides), which act directly in the polyamine-detecting olfactory and taste neurons. This modulation is triggered by an increase of SPR expression in chemosensory neurons, which is sufficient to convert virgin to mated female olfactory choice behavior. Together, our data show that neuropeptide-mediated modulation of peripheral chemosensory neurons increases a gravid female's preference for important nutrients, thereby ensuring optimal conditions for her growing progeny. PMID:27145127

  13. Computational identification of developmental enhancers:conservation and function of transcription factor binding-site clustersin drosophila melanogaster and drosophila psedoobscura

    SciTech Connect

    Berman, Benjamin P.; Pfeiffer, Barret D.; Laverty, Todd R.; Salzberg, Steven L.; Rubin, Gerald M.; Eisen, Michael B.; Celniker, SusanE.

    2004-08-06

    The identification of sequences that control transcription in metazoans is a major goal of genome analysis. In a previous study, we demonstrated that searching for clusters of predicted transcription factor binding sites could discover active regulatory sequences, and identified 37 regions of the Drosophila melanogaster genome with high densities of predicted binding sites for five transcription factors involved in anterior-posterior embryonic patterning. Nine of these clusters overlapped known enhancers. Here, we report the results of in vivo functional analysis of 27 remaining clusters. We generated transgenic flies carrying each cluster attached to a basal promoter and reporter gene, and assayed embryos for reporter gene expression. Six clusters are enhancers of adjacent genes: giant, fushi tarazu, odd-skipped, nubbin, squeeze and pdm2; three drive expression in patterns unrelated to those of neighboring genes; the remaining 18 do not appear to have enhancer activity. We used the Drosophila pseudoobscura genome to compare patterns of evolution in and around the 15 positive and 18 false-positive predictions. Although conservation of primary sequence cannot distinguish true from false positives, conservation of binding-site clustering accurately discriminates functional binding-site clusters from those with no function. We incorporated conservation of binding-site clustering into a new genome-wide enhancer screen, and predict several hundred new regulatory sequences, including 85 adjacent to genes with embryonic patterns. Measuring conservation of sequence features closely linked to function--such as binding-site clustering--makes better use of comparative sequence data than commonly used methods that examine only sequence identity.

  14. Computational identification of developmental enhancers:conservation and function of transcription factor binding-site clustersin drosophila melanogaster and drosophila psedoobscura

    SciTech Connect

    Berman, Benjamin P.; Pfeiffer, Barret D.; Laverty, Todd R.; Salzberg, Steven L.; Rubin, Gerald M.; Eisen, Michael B.; Celniker, SusanE.

    2004-08-06

    Background The identification of sequences that control transcription in metazoans is a major goal of genome analysis. In a previous study, we demonstrated that searching for clusters of predicted transcription factor binding sites could discover active regulatory sequences, and identified 37 regions of the Drosophila melanogaster genome with high densities of predicted binding sites for five transcription factors involved in anterior-posterior embryonic patterning. Nine of these clusters overlapped known enhancers. Here, we report the results of in vivo functional analysis of 27 remaining clusters. Results We generated transgenic flies carrying each cluster attached to a basal promoter and reporter gene, and assayed embryos for reporter gene expression. Six clusters are enhancers of adjacent genes: giant, fushi tarazu, odd-skipped, nubbin, squeeze and pdm2; three drive expression in patterns unrelated to those of neighboring genes; the remaining 18 do not appear to have enhancer activity. We used the Drosophila pseudoobscura genome to compare patterns of evolution in and around the 15 positive and 18 false-positive predictions. Although conservation of primary sequence cannot distinguish true from false positives, conservation of binding-site clustering accurately discriminates functional binding-site clusters from those with no function. We incorporated conservation of binding-site clustering into a new genome-wide enhancer screen, and predict several hundred new regulatory sequences, including 85 adjacent to genes with embryonic patterns. Conclusions Measuring conservation of sequence features closely linked to function - such as binding-site clustering - makes better use of comparative sequence data than commonly used methods that examine only sequence identity.

  15. Gene Regulation Networks for Modeling Drosophila Development

    NASA Technical Reports Server (NTRS)

    Mjolsness, E.

    1999-01-01

    This chapter will very briefly introduce and review some computational experiments in using trainable gene regulation network models to simulate and understand selected episodes in the development of the fruit fly, Drosophila Melanogaster.

  16. Drosophila RNAi screening in a postgenomic world

    PubMed Central

    2011-01-01

    Drosophila melanogaster has a long history as a model organism with several unique features that make it an ideal research tool for the study of the relationship between genotype and phenotype. Importantly fundamental genetic principles as well as key human disease genes have been uncovered through the use of Drosophila. The contribution of the fruit fly to science and medicine continues in the postgenomic era as cell-based Drosophila RNAi screens are a cost-effective and scalable enabling technology that can be used to quantify the contribution of different genes to diverse cellular processes. Drosophila high-throughput screens can also be used as integral part of systems-level approaches to describe the architecture and dynamics of cellular networks. PMID:21752787

  17. Drosophila Cajal bodies: accessories not included

    PubMed Central

    Matera, A. Gregory

    2006-01-01

    Cajal bodies are nuclear sites of small ribonucleoprotein (RNP) remodeling and maturation. A recent study describes the discovery of the Drosophila Cajal body, revealing some interesting insights into the subnuclear organization of RNA processing machineries among different species. PMID:16533940

  18. Targeted genome engineering techniques in Drosophila

    PubMed Central

    Beumer, Kelly J.; Carroll, Dana

    2014-01-01

    For a century, Drosophila has been a favored organism for genetic research. However, the array of materials and methods available to the Drosophila worker has expanded dramatically in the last decade. The most common gene targeting tools, zinc finger nucleases, TALENs, and RNA-guided CRISPR/Cas9, have all been adapted for use in Drosophila, both for simple mutagenesis and for gene editing via homologous recombination. For each tool, there exist a number of web sites, design applications, and delivery methods. The successful application of any of these tools also requires an understanding of methods for detecting successful genome modifications. This article provides an overview of the available gene targeting tools and their application in Drosophila. In lieu of simply providing a protocol for gene targeting, we direct the researcher to resources that will allow access to the latest research in this rapidly evolving field. PMID:24412316

  19. Circadian light-input pathways in Drosophila.

    PubMed

    Yoshii, Taishi; Hermann-Luibl, Christiane; Helfrich-Förster, Charlotte

    2016-01-01

    Light is the most important environmental cue to entrain the circadian clock in most animals. In the fruit fly Drosophila melanogaster, the light entrainment mechanisms of the clock have been well-studied. The Drosophila brain contains approximately 150 neurons that rhythmically express circadian clock genes. These neurons are called "clock neurons" and control behavioral activity rhythms. Many clock neurons express the Cryptochrome (CRY) protein, which is sensitive to UV and blue light, and thus enables clock neurons deep in the brain to directly perceive light. In addition to the CRY protein, external photoreceptors in the Drosophila eyes play an important role in circadian light-input pathways. Recent studies have provided new insights into the mechanisms that integrate these light inputs into the circadian network of the brain. In this review, we will summarize the current knowledge on the light entrainment pathways in the Drosophila circadian clock. PMID:27066180

  20. Ecdysteroid receptors in Drosophila melanogaster adult females

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecdysteroid receptors were identified and partially characterized from total cell extracts of whole animals and dissected tissues from Drosophila melanogaster adult females. Binding studies indicated the presence of two ecdysteroid binding components having high affinity and specificity consistent w...

  1. Colour vision: parallel pathways intersect in Drosophila.

    PubMed

    Kelber, Almut; Henze, Miriam J

    2013-12-01

    In the last one hundred years, colour vision has been demonstrated in bees and many other insects. But the underlying neural wiring remained elusive. A new study on Drosophila melanogaster combining behavioural and genetic tools yields surprising insights. PMID:24309280

  2. Fine-structural changes in the midgut of old Drosophila melanogaster

    NASA Technical Reports Server (NTRS)

    Anton-Erxleben, F.; Miquel, J.; Philpott, D. E.

    1983-01-01

    Senescent fine-structural changes in the midgut of Drosophila melanogaster are investigated. A large number of midgut mitochondria in old flies exhibit nodular cristae and a tubular system located perpendicular to the normal cristae orientation. Anterior intestinal cells show a senescent accumulation of age pigment, either with a surrounding two-unit membrane or without any membrane. The predominant localization of enlarged mitochondria and pigment in the luminal gut region may be related to the polarized metabolism of the intestinal cells. Findings concur with previous observations of dense-body accumulations and support the theory that mitochondria are involved in the aging of fixed post-mitotic cells. Demonstrated by statistical analyses is that mitochondrial size increase is related to mitochondrial variation increase.

  3. Stem-cell-specific endocytic degradation defects lead to intestinal dysplasia in Drosophila

    PubMed Central

    Nagy, Péter; Kovács, Laura; Sándor, Gyöngyvér O.

    2016-01-01

    ABSTRACT UV radiation resistance-associated gene (UVRAG) is a tumor suppressor involved in autophagy, endocytosis and DNA damage repair, but how its loss contributes to colorectal cancer is poorly understood. Here, we show that UVRAG deficiency in Drosophila intestinal stem cells leads to uncontrolled proliferation and impaired differentiation without preventing autophagy. As a result, affected animals suffer from gut dysfunction and short lifespan. Dysplasia upon loss of UVRAG is characterized by the accumulation of endocytosed ligands and sustained activation of STAT and JNK signaling, and attenuation of these pathways suppresses stem cell hyperproliferation. Importantly, the inhibition of early (dynamin-dependent) or late (Rab7-dependent) steps of endocytosis in intestinal stem cells also induces hyperproliferation and dysplasia. Our data raise the possibility that endocytic, but not autophagic, defects contribute to UVRAG-deficient colorectal cancer development in humans. PMID:26921396

  4. Two retrotransposons maintain telomeres in Drosophila

    PubMed Central

    Pardue, M.-L.; Rashkova, S.; Casacuberta, E.; DeBaryshe, P.G.; George, J. A.; Traverse, K.L.

    2005-01-01

    Telomeres across the genus Drosophila are maintained, not by telomerase, but by two non-LTR retrotransposons, HeT-A and TART, that transpose specifically to chromosome ends. Successive transpositions result in long head-to-tail arrays of these elements. Thus Drosophila telomeres, like those produced by telomerase, consist of repeated sequences reverse transcribed from RNA templates. The Drosophila repeats, complete and 5′-truncated copies of HeT-A and TART, are more complex than telomerase repeats; nevertheless these evolutionary variants have functional similarities to the more common telomeres. Like other telomeres, the Drosophila arrays are dynamic, fluctuating around an average length that can be changed by changes in the genetic background. Several proteins that interact with telomeres in other species have been found to have homologues that interact with Drosophila telomeres. Although they have hallmarks of non-LTR retrotransposons, HeT-A and TART appear to have a special relationship to Drosophila. Their Gag proteins are efficiently transported into diploid nuclei where HeT-A Gag recruits TART Gag to chromosome ends. Gags of other non-LTR elements remain predominantly in the cytoplasm. These studies provide intriguing evolutionary links between telomeres and retrotransposable elements. PMID:16132810

  5. A Drosophila Model for Screening Antiobesity Agents

    PubMed Central

    Men, Tran Thanh; Thanh, Duong Ngoc Van; Yamaguchi, Masamitsu; Suzuki, Takayoshi; Hattori, Gen; Arii, Masayuki; Huy, Nguyen Tien; Kamei, Kaeko

    2016-01-01

    Although triacylglycerol, the major component for lipid storage, is essential for normal physiology, its excessive accumulation causes obesity in adipose tissue and is associated with organ dysfunction in nonadipose tissue. Here, we focused on the Drosophila model to develop therapeutics for preventing obesity. The brummer (bmm) gene in Drosophila melanogaster is known to be homologous with human adipocyte triglyceride lipase, which is related to the regulation of lipid storage. We established a Drosophila model for monitoring bmm expression by introducing the green fluorescent protein (GFP) gene as a downstream reporter of the bmm promoter. The third-instar larvae of Drosophila showed the GFP signal in all tissues observed and specifically in the salivary gland nucleus. To confirm the relationship between bmm expression and obesity, the effect of oral administration of glucose diets on bmm promoter activity was analyzed. The Drosophila flies given high-glucose diets showed higher lipid contents, indicating the obesity phenotype; this was suggested by a weaker intensity of the GFP signal as well as reduced bmm mRNA expression. These results demonstrated that the transgenic Drosophila model established in this study is useful for screening antiobesity agents. We also report the effects of oral administration of histone deacetylase inhibitors and some vegetables on the bmm promoter activity. PMID:27247940

  6. Remote Control of Intestinal Stem Cell Activity by Haemocytes in Drosophila

    PubMed Central

    Chakrabarti, Sveta; Li, Xiaoxue; Collas, Esther Jeanne; Boquete, Jean-Phillipe; Lemaitre, Bruno

    2016-01-01

    The JAK/STAT pathway is a key signaling pathway in the regulation of development and immunity in metazoans. In contrast to the multiple combinatorial JAK/STAT pathways in mammals, only one canonical JAK/STAT pathway exists in Drosophila. It is activated by three secreted proteins of the Unpaired family (Upd): Upd1, Upd2 and Upd3. Although many studies have established a link between JAK/STAT activation and tissue damage, the mode of activation and the precise function of this pathway in the Drosophila systemic immune response remain unclear. In this study, we used mutations in upd2 and upd3 to investigate the role of the JAK/STAT pathway in the systemic immune response. Our study shows that haemocytes express the three upd genes and that injury markedly induces the expression of upd3 by the JNK pathway in haemocytes, which in turn activates the JAK/STAT pathway in the fat body and the gut. Surprisingly, release of Upd3 from haemocytes upon injury can remotely stimulate stem cell proliferation and the expression of Drosomycin-like genes in the intestine. Our results also suggest that a certain level of intestinal epithelium renewal is required for optimal survival to septic injury. While haemocyte-derived Upd promotes intestinal stem cell activation and survival upon septic injury, haemocytes are dispensable for epithelium renewal upon oral bacterial infection. Our study also indicates that intestinal epithelium renewal is sensitive to insults from both the lumen and the haemocoel. It also reveals that release of Upds by haemocytes coordinates the wound-healing program in multiple tissues, including the gut, an organ whose integrity is critical to fly survival. PMID:27231872

  7. A bio-NanoRobot design for drosophila therapeutic cloning

    NASA Astrophysics Data System (ADS)

    Chang, Chia-Pin; Szu, Harold

    2006-04-01

    To investigate Somatic Cell Nuclear Transfer (SCNT), we choose the Drosophila cloning based on a recent experiment (Haigh, MacDonald, Lioyd, Gen. V.169,1165, 2005) to be improving the adulthood rate in 2-week turn-around time. Original 1% success rate might be due to three less certain key steps: (i) The double membranes of a nucleus has at its pore led to the attached Rough Endoplasmic Reticulum (ER), passing the genetic instruction to assemble amino acids, proteins and lipid at its smooth end. Also, any mismatch of nucleus with mitochondria (MT) having own small genome for energy production had led to reprogramming failure. (D. Wallace, UC Irvine, Nature,Vol. 439, pp.653). We ask "whether a guest DNA shall come with its servants, ER, MT, etc or not." It seemed to be logical to have a whole package replaced the embryonic host cell, equipped with all housekeeping, energy production and mitosis functionalities except the genetic information. To answer this hypothesis, we design a bio-NanoRobot having a surgical precision in removing the desired nucleus with or without its attached ER and MT material. The design is based on a real-time multiplexing principle of combining both the soft-contact-vision of the Nobel Laureate Binning called Atomic Force Microscope (AFM) and the hard-grasp-action called NanoRobot TM by Xi and Szu, 2004. However, applying it, we must re-design a new bio-NanoRobot, consisting of two parts: (a) multiple resolution analysis (MRA) using AI to control a dual-resolution vision system: the soft-contact-vision AFM co-registered with a on-contact high resolution imaging; and (b) two cantilever arms capable to hold and enucleate a cell. The calibration and automation are controlled by AI Case-Based reasoning (CBR) together with AI Blackboard (BB) of the taxonomy, necessary for integrating different tool's tolerance and resolution at the same location. Moreover, keeping the biological sample in one place, while a set of tools rotates upon it similar

  8. Gut Bacteria in Health and Disease

    PubMed Central

    2013-01-01

    A new era in medical science has dawned with the realization of the critical role of the “forgotten organ,” the gut micro-biota, in health and disease. Central to this beneficial interaction between the microbiota and host is the manner in which bacteria and most likely other microorganisms contained within the gut communicate with the host’s immune system and participate in a variety of metabolic processes of mutual benefit to the host and the microbe. The advent of high-throughput methodologies and the elaboration of sophisticated analytic systems have facilitated the detailed description of the composition of the microbial constituents of the human gut, as never before, and are now enabling comparisons to be made between health and various disease states. Although the latter approach is still in its infancy, some important insights have already been gained about how the microbiota might influence a number of disease processes both within and distant from the gut. These discoveries also lay the groundwork for the development of therapeutic strategies that might modify the microbiota (eg, through the use of probiot-ics). Although this area holds much promise, more high-quality trials of probiotics, prebiotics, and other microbiota-modifying approaches in digestive disorders are needed, as well as laboratory investigations of their mechanisms of action. PMID:24729765

  9. The Enigmatic Universe of the Herbivore Gut.

    PubMed

    Glass, N Louise

    2016-07-01

    The herbivore gut is a fascinating ecosystem exquisitely adapted to plant biomass degradation. Within this ecosystem, anaerobic fungi invade biomass and secrete hydrolytic enzymes. In a recent study, Solomon et al. characterized three anaerobic fungi by transcriptomics, proteomics, and functional analyses to identify novel components essential for plant biomass deconstruction. PMID:27257096

  10. The human gut virome: a multifaceted majority

    PubMed Central

    Ogilvie, Lesley A.; Jones, Brian V.

    2015-01-01

    Here, we outline our current understanding of the human gut virome, in particular the phage component of this ecosystem, highlighting progress, and challenges in viral discovery in this arena. We reveal how developments in high-throughput sequencing technologies and associated data analysis methodologies are helping to illuminate this abundant ‘biological dark matter.’ Current evidence suggests that the human gut virome is a highly individual but temporally stable collective, dominated by phages exhibiting a temperate lifestyle. This viral community also appears to encode a surprisingly rich functional repertoire that confers a range of attributes to their bacterial hosts, ranging from bacterial virulence and pathogenesis to maintaining host–microbiome stability and community resilience. Despite the significant advances in our understanding of the gut virome in recent years, it is clear that we remain in a period of discovery and revelation, as new methods and technologies begin to provide deeper understanding of the inherent ecological characteristics of this viral ecosystem. As our understanding increases, the nature of the multi-partite interactions occurring between host and microbiome will become clearer, helping us to more rationally define the concepts and principles that will underpin approaches to using human gut virome components for medical or biotechnological applications. PMID:26441861

  11. Diet, the Gut Microbiome, and Epigenetics

    PubMed Central

    Hullar, Meredith A. J.; Fu, Benjamin C.

    2014-01-01

    Increasingly, the gut microbiome is implicated in the etiology of cancer, not only as an infectious agent, but also by altering exposure to dietary compounds that influence disease risk. While the composition and metabolism of the gut microbiome is influenced by diet, the gut microbiome can also modify dietary exposures in ways that are beneficial or detrimental to the human host. The colonic bacteria metabolize macronutrients, either as specialists or in consortia of bacteria, in a variety of diverse metabolic pathways. Microbial metabolites of diet can also be epigenetic activators of gene expression that may influence cancer risk in humans. Epigenetic involves heritable changes in gene expression via post translational and post transcriptional modifications. Microbial metabolites can influence epigenetics by altering the pool of compounds used for modification or by directly inhibiting enzymes involved in epigenetic pathways. Colonic epithelium is immediately exposed to these metabolites, although some metabolites are also found in systemic circulation. In this review, we discuss the role of the gut microbiome in dietary metabolism and how microbial metabolites may influence gene expression linked to colon cancer risk. PMID:24855003

  12. Gut-liver axis: role of inflammasomes.

    PubMed

    Bawa, Manan; Saraswat, Vivek A

    2013-06-01

    Inflammasomes are large multiprotein complexes that have the ability to sense intracellular danger signals through special NOD-like receptors or NLRs. They include NLRP3, NLRC4, AIM2 and NLRP6. They are involved in recognizing diverse microbial (bacteria, viruses, fungi and parasites), stress and damage signals, which result in direct activation of caspase-1, leading to secretion of potent pro-inflammatory cytokines and pyroptosis. NLRP3 is the most studied antimicrobial immune response inflammasome. Recent studies reveal expression of inflammasomes in innate immune response cells including monocytes, macrophages, neutrophils, and dendritic cells. Inflammasome deficiency has been linked to alterations in the gastrointestinal microflora. Alterations in the microbiome population and/or changes in gut permeability promote microbial translocation into the portal circulation and thus directly to the liver. Gut derived lipopolysaccharides (LPS) play a significant role in several liver diseases. Recent advancements in the sequencing technologies along with improved methods in metagenomics and bioinformatics have provided effective tools for investigating the 10(14) microorganisms of the human microbiome that inhabit the human gut. In this review, we examine the significance of inflammasomes in relation to the gut microflora and liver. This review also highlights the emerging functions of human microbiota in health and liver diseases. PMID:25755488

  13. 'Gut health': a new objective in medicine?

    PubMed Central

    2011-01-01

    'Gut health' is a term increasingly used in the medical literature and by the food industry. It covers multiple positive aspects of the gastrointestinal (GI) tract, such as the effective digestion and absorption of food, the absence of GI illness, normal and stable intestinal microbiota, effective immune status and a state of well-being. From a scientific point of view, however, it is still extremely unclear exactly what gut health is, how it can be defined and how it can be measured. The GI barrier adjacent to the GI microbiota appears to be the key to understanding the complex mechanisms that maintain gut health. Any impairment of the GI barrier can increase the risk of developing infectious, inflammatory and functional GI diseases, as well as extraintestinal diseases such as immune-mediated and metabolic disorders. Less clear, however, is whether GI discomfort in general can also be related to GI barrier functions. In any case, methods of assessing, improving and maintaining gut health-related GI functions are of major interest in preventive medicine. PMID:21401922

  14. Isolation of methanotrophic bacteria from termite gut.

    PubMed

    Reuss, Julia; Rachel, Reinhard; Kämpfer, Peter; Rabenstein, Andreas; Küver, Jan; Dröge, Stefan; König, Helmut

    2015-10-01

    The guts of termites feature suitable conditions for methane oxidizing bacteria (MOB) with their permanent production of CH4 and constant supply of O2 via tracheae. In this study, we have isolated MOB from the gut contents of the termites Incisitermes marginipennis, Mastotermes darwiniensis, and Neotermes castaneus for the first time. The existence of MOB was indicated by detecting pmoA, the gene for the particulate methane monooxygenase, in the DNA of gut contents. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction supported those findings. The MOB cell titer was determined to be 10(2)-10(3) per gut. Analyses of the 16S rDNA from isolates indicated close similarity to the genus Methylocystis. After various physiological tests and fingerprinting methods, no exact match to a known species was obtained, indicating the isolation of new MOB species. However, MALDI-TOF MS analyses revealed a close relationship to Methylocystis bryophila and Methylocystis parvus. PMID:26411892

  15. Gut microbiota of Busseola fusca (Lepidoptera: Noctuidae).

    PubMed

    Snyman, Maxi; Gupta, Arvind Kumar; Bezuidenhout, Cornelius Carlos; Claassens, Sarina; van den Berg, Johnnie

    2016-07-01

    Busseola fusca (Fuller) (Lepidoptera: Noctuidae) is a stemborer pest that attacks maize (Zea mays) throughout sub-Saharan Africa. Genetically modified maize has been shown to be effective against B. fusca. However, resistance of B. fusca against Bt-maize has developed and spread throughout South Africa. Previous studies suggested that gut microbiota contribute to mortality across a range of Lepidoptera. To fully assess the role of microbiota within the gut, it is essential to understand the microbiota harboured by natural B. fusca populations. This study aimed to identify the gut-associated bacteria by 16S rRNA gene sequencing. A total of 78 bacterial strains were characterised from the midgut of B. fusca larvae that were collected from 30 sites across the maize producing region of South Africa. Molecular phylogenetic analyses revealed bacteria affiliated to Proteobacteria, Actinobacteria, and Firmicutes. Taxonomic distribution placed these isolates into 15 different genera representing 20 species. The majority of bacteria identified belong to the genera Bacillus, Enterococcus, and Klebsiella. The B. fusca gut represents an intriguing and unexplored niche for analysing microbial ecology. The study could provide opportunities for developing new targets for pest management and contribute to understanding the phenomenon of resistance evolution of this species. PMID:27263010

  16. Gut Microbiota and Lifestyle Interventions in NAFLD.

    PubMed

    Houghton, David; Stewart, Christopher J; Day, Christopher P; Trenell, Michael

    2016-01-01

    The human digestive system harbors a diverse and complex community of microorganisms that work in a symbiotic fashion with the host, contributing to metabolism, immune response and intestinal architecture. However, disruption of a stable and diverse community, termed "dysbiosis", has been shown to have a profound impact upon health and disease. Emerging data demonstrate dysbiosis of the gut microbiota to be linked with non-alcoholic fatty liver disease (NAFLD). Although the exact mechanism(s) remain unknown, inflammation, damage to the intestinal membrane, and translocation of bacteria have all been suggested. Lifestyle intervention is undoubtedly effective at improving NAFLD, however, not all patients respond to these in the same manner. Furthermore, studies investigating the effects of lifestyle interventions on the gut microbiota in NAFLD patients are lacking. A deeper understanding of how different aspects of lifestyle (diet/nutrition/exercise) affect the host-microbiome interaction may allow for a more tailored approach to lifestyle intervention. With gut microbiota representing a key element of personalized medicine and nutrition, we review the effects of lifestyle interventions (diet and physical activity/exercise) on gut microbiota and how this impacts upon NAFLD prognosis. PMID:27023533

  17. Gut ecosystem: how microbes help us.

    PubMed

    Martín, R; Miquel, S; Ulmer, J; Langella, P; Bermúdez-Humarán, L G

    2014-09-01

    The human gut houses one of the most complex and abundant ecosystems composed of up to 1013-1014 microorganisms. Although the anthropocentric concept of life has concealed the function of microorganisms inside us, the important role of gut bacterial community in human health is well recognised today. Moreover, different microorganims, which are commonly present in a large diversity of food products, transit through our gut every day adding in some cases a beneficial effect to our health (probiotics). This crosstalk is concentrated mainly in the intestinal epithelium, where microbes provide the host with essential nutrients and modulation of the immune system. Furthermore, microorganisms also display antimicrobial activities maintaining a gut ecosystem stable. This review summarises some of the recent findings on the interaction of both commensal and probiotic bacteria with each other and with the host. The aim is to highlight the cooperative status found in healthy individuals as well as the importance of this crosstalk in the maintenance of human homeostasis. PMID:24583612

  18. Nutritional protective mechanisms against gut inflammation☆

    PubMed Central

    Viladomiu, Monica; Hontecillas, Raquel; Yuan, Lijuan; Lu, Pinyi; Bassaganya-Riera, Josep

    2013-01-01

    Inflammatory bowel disease (IBD) is a debilitating and widespread immune-mediated illness characterized by excessive inflammatory and effector mucosal responses leading to tissue destruction at the gastrointestinal tract. Interactions among the immune system, the commensal microbiota and the host genotype are thought to underlie the pathogenesis of IBD. However, the precise etiology of IBD remains unknown. Diet-induced changes in the composition of the gut microbiome can modulate the induction of regulatory versus effector immune responses at the gut mucosa and improve health outcomes. Therefore, manipulation of gut microbiota composition and the local production of microbial-derived metabolites by using prebiotics, probiotics and dietary fibers is being explored as a promising avenue of prophylactic and therapeutic intervention against gut inflammation. Prebiotics and fiber carbohydrates are fermented by resident microflora into short chain fatty acids (SCFAs) in the colon. SCFAs then activate peroxisome proliferator-activated receptor (PPAR)γ, a nuclear transcription factor with widely demonstrated anti-inflammatory efficacy in experimental IBD. The activation of PPARγ by naturally ocurring compounds such as conjugated linoleic acid, pomegranate seed oil-derived punicic acid, eleostearic acid and abscisic acid has been explored as nutritional interventions that suppress colitis by directly modulating the host immune response. The aim of this review is to summarize the status of innovative nutritional interventions against gastrointestinal inflammation, their proposed mechanisms of action, preclinical and clinical efficacy as well as bioinformatics and computational modeling approaches that accelerate discovery in nutritional and mucosal immunology research. PMID:23541470

  19. The Gut Bacteria-Driven Obesity Development.

    PubMed

    Compare, Debora; Rocco, Alba; Sanduzzi Zamparelli, Marco; Nardone, Gerardo

    2016-01-01

    It is now well established that a healthy gut flora is largely responsible for the overall health of the host, while a perturbation in gut microbial communities can contribute to disease susceptibility. Obesity is a complex process involving genetic and environmental factors with an epidemiological burden that makes it a major public health issue. Studies of germ-free or gnotobiotic mice provided evidence that the diversity, as well as the presence and relative proportion of different microbes in the gut play active roles in energy homeostasis. Similarly, human studies showed that both the diversity of the microbiota and the Bacteroidetes/Firmicutes ratio are decreased in obese individuals. The 'obese microbiota' seems to be able to increase dietary energy harvest and favor weight gain and fat deposition. Although research in this field has just started and many of the available data are still conflicting, the results are providing exciting perspectives, and gut microbiota manipulation has already become a new target for both prevention and treatment of obesity. PMID:27028448

  20. Gut Microbiota and Allergic Disease. New Insights.

    PubMed

    Lynch, Susan V

    2016-03-01

    The rapid rise in childhood allergies (atopy) in Westernized nations has implicated associated environmental exposures and lifestyles as primary drivers of disease development. Culture-based microbiological studies indicate that atopy has demonstrable ties to altered gut microbial colonization in very early life. Infants who exhibit more severe multisensitization to food- or aero-allergens have a significantly higher risk of subsequently developing asthma in childhood. Hence an emerging hypothesis posits that environment- or lifestyle-driven aberrancies in the early-life gut microbiome composition and by extension, microbial function, represent a key mediator of childhood allergic asthma. Animal studies support this hypothesis. Environmental microbial exposures epidemiologically associated with allergy protection in humans confer protection against airway allergy in mice. In addition, gut microbiome-derived short-chain fatty acids produced from a high-fiber diet have been shown to protect against allergy via modulation of both local and remote mucosal immunity as well as hematopoietic antigen-presenting cell populations. Here we review key data supporting the concept of a gut-airway axis and its critical role in childhood atopy. PMID:27027953

  1. Obesity Surgery and Gut-Brain Communication

    PubMed Central

    Berthoud, Hans-Rudolf; Shin, Andrew C.; Zheng, Huiyuan

    2011-01-01

    The prevalence of obesity, and the cluster of serious metabolic diseases it is associated with, continues to rise globally, and hopes for effective treatment with drugs have been considerably set back. Thus, success with bariatric surgeries to induce sustained body weight loss and effectively cure most of the associated co-morbidities appears almost “miraculous” and systematic investigation of the mechanisms at work has gained momentum. Here, we will discuss the basic organization of gut-brain communication and review clinical and pre-clinical investigations on the potential mechanisms by which gastric bypass surgery leads to its beneficial effects on energy balance and glucose homeostasis. Although a lot has been learned regarding changes in energy intake and expenditure, secretion of gut hormones, and improvement in glucose homeostasis, there has not yet been the “breakthrough observation” of identifying a key signaling component common to the beneficial effects of the surgery. However, given the complexity and redundancy of gut-brain signaling and gut signaling to other relevant organs, it is perhaps more realistic to expect a number of key signaling changes that act in concert to bring about the “miracle”. PMID:21315095

  2. Gut Microbiota and Lifestyle Interventions in NAFLD

    PubMed Central

    Houghton, David; Stewart, Christopher J.; Day, Christopher P.; Trenell, Michael

    2016-01-01

    The human digestive system harbors a diverse and complex community of microorganisms that work in a symbiotic fashion with the host, contributing to metabolism, immune response and intestinal architecture. However, disruption of a stable and diverse community, termed “dysbiosis”, has been shown to have a profound impact upon health and disease. Emerging data demonstrate dysbiosis of the gut microbiota to be linked with non-alcoholic fatty liver disease (NAFLD). Although the exact mechanism(s) remain unknown, inflammation, damage to the intestinal membrane, and translocation of bacteria have all been suggested. Lifestyle intervention is undoubtedly effective at improving NAFLD, however, not all patients respond to these in the same manner. Furthermore, studies investigating the effects of lifestyle interventions on the gut microbiota in NAFLD patients are lacking. A deeper understanding of how different aspects of lifestyle (diet/nutrition/exercise) affect the host–microbiome interaction may allow for a more tailored approach to lifestyle intervention. With gut microbiota representing a key element of personalized medicine and nutrition, we review the effects of lifestyle interventions (diet and physical activity/exercise) on gut microbiota and how this impacts upon NAFLD prognosis. PMID:27023533

  3. Prebiotics and gut microbiota in chickens.

    PubMed

    Pourabedin, Mohsen; Zhao, Xin

    2015-08-01

    Prebiotics are non-digestible feed ingredients that are metabolized by specific members of intestinal microbiota and provide health benefits for the host. Fermentable oligosaccharides are best known prebiotics that have received increasing attention in poultry production. They act through diverse mechanisms, such as providing nutrients, preventing pathogen adhesion to host cells, interacting with host immune systems and affecting gut morphological structure, all presumably through modulation of intestinal microbiota. Currently, fructooligosaccharides, inulin and mannanoligosaccharides have shown promising results while other prebiotic candidates such as xylooligosaccharides are still at an early development stage. Despite a growing body of evidence reporting health benefits of prebiotics in chickens, very limited studies have been conducted to directly link health improvements to prebiotic-dependent changes in the gut microbiota. This article visits the current knowledge of the chicken gastrointestinal microbiota and reviews most recent publications related to the roles played by prebiotics in modulation of the gut microbiota and immune functions. Progress in this field will help us better understand how the gut microbiota contributes to poultry health and productivity, and support the development of new prebiotic products as an alternative to in-feed antibiotics. PMID:26208530

  4. Redefining the gut as the motor of critical illness

    PubMed Central

    Mittal, Rohit; Coopersmith, Craig M.

    2013-01-01

    The gut is hypothesized to play a central role in the progression of sepsis and multiple organ dysfunction syndrome. Critical illness alters gut integrity by increasing epithelial apoptosis and permeability and by decreasing epithelial proliferation and mucus integrity. Additionally, toxic gut-derived lymph induces distant organ injury. Although the endogenous microflora ordinarily exist in a symbiotic relationship with the gut epithelium, severe physiologic insults alter this relationship, leading to induction of virulence factors in the microbiome, which, in turn, can perpetuate or worsen critical illness. This review highlights newly discovered ways in which the gut acts as the motor that perpetuates the systemic inflammatory response in critical illness. PMID:24055446

  5. Redefining the gut as the motor of critical illness.

    PubMed

    Mittal, Rohit; Coopersmith, Craig M

    2014-04-01

    The gut is hypothesized to play a central role in the progression of sepsis and multiple organ dysfunction syndrome. Critical illness alters gut integrity by increasing epithelial apoptosis and permeability and by decreasing epithelial proliferation and mucus integrity. Additionally, toxic gut-derived lymph induces distant organ injury. Although the endogenous microflora ordinarily exist in a symbiotic relationship with the gut epithelium, severe physiological insults alter this relationship, leading to induction of virulence factors in the microbiome, which, in turn, can perpetuate or worsen critical illness. This review highlights newly discovered ways in which the gut acts as the motor that perpetuates the systemic inflammatory response in critical illness. PMID:24055446

  6. Postharvest treatment of strawberries with methyl bromide to control spotted wing drosophila, Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted wing drosophila (SWD), Drosophila suzukii, is a pest of concern to countries that import strawberries from California USA. The purpose of this investigation was to verify elimination of SWD in California-grown fresh strawberries under conditions consistent with export to Australia; a 3-h fum...

  7. Current Recommendations for Managing Spotted Wing Drosophila (SWD), Drosophila suzukii, in PNW Strawberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spotted wing Drosophila (SWD), Drosophila suzukii, was reported in the Pacific Northwest (Oregon, Washington, British Columbia) in 2009. The fly is able to oviposit directly into intact ripe and ripening fruit, so it is of great economic concern to the small fruit industries in region. Fruit i...

  8. Current Recommendations for Managing Spotted Wing Drosophila (SWD), Drosophila suzukii, in PNW Blueberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spotted wing Drosophila (SWD), Drosophila suzukii, was reported in the Pacific Northwest (Oregon, Washington, British Columbia) in 2009. The fly is able to oviposit directly into intact ripe and ripening fruit, so it is of great economic concern to the small fruit industries in region. Fruit i...

  9. Current Recommendations for Managing Spotted Wing Drosophila (SWD), Drosophila suzukii, in PNW Caneberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spotted wing Drosophila (SWD), Drosophila suzukii, was reported in the Pacific Northwest (Oregon, Washington, British Columbia) in 2009. The fly is able to oviposit directly into intact ripe and ripening fruit, so it is of great economic concern to the small fruit industries in region. Fruit i...

  10. The susceptibility of small fruits and cherries to Spotted Wing Drosophila, Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: The Spotted Wing Drosophila (SWD), Drosophila suzukii Matsumura, is native to Asia and has been detected in the North American mainland and Europe in 2008-10. SWD is a serious economic pest because it lays eggs within ripening fruit before harvest which can lead to crop loss. The aim ...

  11. Behavioral and antennal responses of spotted wing drosophila, drosophila suzukii, to volatiles from fruit extracts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Native to Southeast Asia, the spotted wing drosophila, Drosophila suzukii, has become a serious pest of soft-skinned fruit crops since its introduction into North America and Europe in 2008. Current monitoring strategies use baits based on fermentation products; however, to date, no fruit-based vola...

  12. Invasion biology of Spotted Wing Drosophila (Drosophila suzukii): a global perspective and future priorities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Asian vinegar fly species Drosophila suzukii (spotted-wing Drosophila or SWD) has emerged as an important invasive insect pest of small and stone fruits in both the Americas and Europe since the late 2000’s. While research efforts have rapidly progressed in Asia, North America, and Europe over ...

  13. Spotted wing drosophila, Drosophila suzukii (Matsumura)(Diptera: drosophilidae), trapped with combinations of wines and vinegars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field trapping experiments evaluated wine and vinegar baits for spotted wing drosophila flies, Drosophila suzukii (Matsumura), and assessed variance in biat attractiveness with wit type, vinegar type, and bait age. A mixture of apple cider vinegar and a Merlot wine attracted more flies than a mixtur...

  14. Regulation of energy balance by a gut-brain axis and involvement of the gut microbiota.

    PubMed

    Bauer, Paige V; Hamr, Sophie C; Duca, Frank A

    2016-02-01

    Despite significant progress in understanding the homeostatic regulation of energy balance, successful therapeutic options for curbing obesity remain elusive. One potential target for the treatment of obesity is via manipulation of the gut-brain axis, a complex bidirectional communication system that is crucial in maintaining energy homeostasis. Indeed, ingested nutrients induce secretion of gut peptides that act either via paracrine signaling through vagal and non-vagal neuronal relays, or in an endocrine fashion via entry into circulation, to ultimately signal to the central nervous system where appropriate responses are generated. We review here the current hypotheses of nutrient sensing mechanisms of enteroendocrine cells, including the release of gut peptides, mainly cholecystokinin, glucagon-like peptide-1, and peptide YY, and subsequent gut-to-brain signaling pathways promoting a reduction of food intake and an increase in energy expenditure. Furthermore, this review highlights recent research suggesting this energy regulating gut-brain axis can be influenced by gut microbiota, potentially contributing to the development of obesity. PMID:26542800

  15. The Gut Epithelial Receptor LRRC19 Promotes the Recruitment of Immune Cells and Gut Inflammation.

    PubMed

    Cao, Shuisong; Su, Xiaomin; Zeng, Benhua; Yan, Hui; Huang, Yugang; Wang, Enlin; Yun, Huan; Zhang, Yuan; Liu, Feifei; Li, Wenxia; Wei, Hong; Che, Yongzhe; Yang, Rongcun

    2016-02-01

    Commensal microbes are necessary for a healthy gut immune system. However, the mechanism involving these microbes that establish and maintain gut immune responses is largely unknown. Here, we have found that the gut immune receptor leucine-rich repeat (LRR) C19 is involved in host-microbiota interactions. LRRC19 deficiency not only impairs the gut immune system but also reduces inflammatory responses in gut tissues. We demonstrate that the LRRC19-associated chemokines CCL6, CCL9, CXCL9, and CXCL10 play a critical role in immune cell recruitment and intestinal inflammation. The expression of these chemokines is associated with regenerating islet-derived (REG) protein-mediated microbiotas. We also found that the expression of REGs may be regulated by gut Lactobacillus through LRRC19-mediated activation of NF-κB. Therefore, our study establishes a regulatory axis of LRRC19, REGs, altered microbiotas, and chemokines for the recruitment of immune cells and the regulation of intestinal inflammation. PMID:26776522

  16. The Gut Epithelial Receptor LRRC19 Promotes the Recruitment of Immune Cells and Gut Inflammation

    PubMed Central

    Cao, Shuisong; Su, Xiaomin; Zeng, Benhua; Yan, Hui; Huang, Yugang; Wang, Enlin; Yun, Huan; Zhang, Yuan; Liu, Feifei; Li, Wenxia; Wei, Hong; Che, Yongzhe; Yang, Rongcun

    2016-01-01

    Summary Commensal microbes are necessary for a healthy gut immune system. However, the mechanism involving these microbes that establish and maintain gut immune responses is largely unknown. Here, we have found that the gut immune receptor leucine-rich repeat (LRR) C19 is involved in host-microbiota interactions. LRRC19 deficiency not only impairs the gut immune system but also reduces inflammatory responses in gut tissues. We demonstrate that the LRRC19-associated chemokines CCL6, CCL9, CXCL9, and CXCL10 play a critical role in immune cell recruitment and intestinal inflammation. The expression of these chemokines is associated with regenerating islet-derived (REG) protein-mediated microbiotas. We also found that the expression of REGs may be regulated by gut Lactobacillus through LRRC19-mediated activation of NF-κB. Therefore, our study establishes a regulatory axis of LRRC19, REGs, altered microbiotas, and chemokines for the recruitment of immune cells and the regulation of intestinal inflammation. PMID:26776522

  17. Fliih, a Gelsolin-Related Cytoskeletal Regulator Essential for Early Mammalian Embryonic Development

    PubMed Central

    Campbell, Hugh D.; Fountain, Shelley; McLennan, Ian S.; Berven, Leise A.; Crouch, Michael F.; Davy, Deborah A.; Hooper, Jane A.; Waterford, Kynan; Chen, Ken-Shiung; Lupski, James R.; Ledermann, Birgit; Young, Ian G.; Matthaei, Klaus I.

    2002-01-01

    The Drosophila melanogaster flightless I gene is required for normal cellularization of the syncytial blastoderm. Highly conserved homologues of flightless I are present in Caenorhabditis elegans, mouse, and human. We have disrupted the mouse homologue Fliih by homologous recombination in embryonic stem cells. Heterozygous Fliih mutant mice develop normally, although the level of Fliih protein is reduced. Cultured homozygous Fliih mutant blastocysts hatch, attach, and form an outgrowing trophoblast cell layer, but egg cylinder formation fails and the embryos degenerate. Similarly, Fliih mutant embryos initiate implantation in vivo but then rapidly degenerate. We have constructed a transgenic mouse carrying the complete human FLII gene and shown that the FLII transgene is capable of rescuing the embryonic lethality of the homozygous targeted Fliih mutation. These results confirm the specific inactivation of the Fliih gene and establish that the human FLII gene and its gene product are functional in the mouse. The Fliih mouse mutant phenotype is much more severe than in the case of the related gelsolin family members gelsolin, villin, and CapG, where the homozygous mutant mice are viable and fertile but display alterations in cytoskeletal actin regulation. PMID:11971982

  18. Polarized E-cadherin endocytosis directs actomyosin remodeling during embryonic wound repair

    PubMed Central

    Hunter, Miranda V.; Lee, Donghoon M.; Harris, Tony J.C.

    2015-01-01

    Embryonic epithelia have a remarkable ability to rapidly repair wounds. A supracellular actomyosin cable around the wound coordinates cellular movements and promotes wound closure. Actomyosin cable formation is accompanied by junctional rearrangements at the wound margin. We used in vivo time-lapse quantitative microscopy to show that clathrin, dynamin, and the ADP-ribosylation factor 6, three components of the endocytic machinery, accumulate around wounds in Drosophila melanogaster embryos in a process that requires calcium signaling and actomyosin contractility. Blocking endocytosis with pharmacological or genetic approaches disrupted wound repair. The defect in wound closure was accompanied by impaired removal of E-cadherin from the wound edge and defective actomyosin cable assembly. E-cadherin overexpression also resulted in reduced actin accumulation around wounds and slower wound closure. Reducing E-cadherin levels in embryos in which endocytosis was blocked rescued actin localization to the wound margin. Our results demonstrate a central role for endocytosis in wound healing and indicate that polarized E-cadherin endocytosis is necessary for actomyosin remodeling during embryonic wound repair. PMID:26304727

  19. Polarized E-cadherin endocytosis directs actomyosin remodeling during embryonic wound repair.

    PubMed

    Hunter, Miranda V; Lee, Donghoon M; Harris, Tony J C; Fernandez-Gonzalez, Rodrigo

    2015-08-31

    Embryonic epithelia have a remarkable ability to rapidly repair wounds. A supracellular actomyosin cable around the wound coordinates cellular movements and promotes wound closure. Actomyosin cable formation is accompanied by junctional rearrangements at the wound margin. We used in vivo time-lapse quantitative microscopy to show that clathrin, dynamin, and the ADP-ribosylation factor 6, three components of the endocytic machinery, accumulate around wounds in Drosophila melanogaster embryos in a process that requires calcium signaling and actomyosin contractility. Blocking endocytosis with pharmacological or genetic approaches disrupted wound repair. The defect in wound closure was accompanied by impaired removal of E-cadherin from the wound edge and defective actomyosin cable assembly. E-cadherin overexpression also resulted in reduced actin accumulation around wounds and slower wound closure. Reducing E-cadherin levels in embryos in which endocytosis was blocked rescued actin localization to the wound margin. Our results demonstrate a central role for endocytosis in wound healing and indicate that polarized E-cadherin endocytosis is necessary for actomyosin remodeling during embryonic wound repair. PMID:26304727

  20. Chibby functions in Xenopus ciliary assembly, embryonic development, and the regulation of gene expression

    PubMed Central

    Shi, Jianli; Zhao, Ying; Galati, Domenico; Winey, Mark; Klymkowsky, Michael W.

    2015-01-01

    Wnt signaling and ciliogenesis are core features of embryonic development in a range of metazoans. Chibby (Cby), a basal-body associated protein, regulates β-catenin-mediated Wnt signaling in the mouse but not Drosophila. Here we present an analysis of Cby’s embryonic expression and morphant phenotypes in Xenopus laevis. Cby RNA is supplied maternally, negatively regulated by Snail2 but not Twist1, preferentially expressed in the neuroectoderm, and regulates β-catenin-mediated gene expression. Reducing Cby levels reduced the density of multiciliated cells, the number of basal bodies per multiciliated cell, and the numbers of neural tube primary cilia; it also led to abnormal development of the neural crest, central nervous system, and pronephros, all defects that were rescued by a Cby-GFP chimera. Reduction of Cby led to an increase in Wnt8a and decreases in Gli2, Gli3, and Shh RNA levels. Many, but not all, morphant phenotypes were significantly reversed by the Wnt inhibitor SFRP2. These observations extend our understanding of Cby’s role in mediating the network of interactions between ciliogenesis, signaling systems and tissue patterning. PMID:25220153

  1. Homotypic Regulatory Clusters in Drosophila

    PubMed Central

    Lifanov, Alexander P.; Makeev, Vsevolod J.; Nazina, Anna G.; Papatsenko, Dmitri A.

    2003-01-01

    Cis-regulatory modules (CRMs) are transcription regulatory DNA segments (∼1 Kb range) that control the expression of developmental genes in higher eukaryotes. We analyzed clustering of known binding motifs for transcription factors (TFs) in over 60 known CRMs from 20 Drosophila developmental genes, and we present evidence that each type of recognition motif forms significant clusters within the regulatory regions regulated by the corresponding TF. We demonstrate how a search with a single binding motif can be applied to explore gene regulatory networks and to discover coregulated genes in the genome. We also discuss the potential of the clustering method in interpreting the differential response of genes to various levels of transcriptional regulators. PMID:12670999

  2. Investigating Spermatogenesis in Drosophila melanogaster

    PubMed Central

    Demarco, Rafael S.; Eikenes, Åsmund H.; Haglund, Kaisa; Jones, D. Leanne

    2014-01-01

    The process of spermatogenesis in Drosophila melanogaster provides a powerful model system to probe a variety of developmental and cell biological questions, such as the characterization of mechanisms that regulate stem cell behavior, cytokinesis, meiosis, and mitochondrial dynamics. Classical genetic approaches, together with binary expression systems, FRT-mediated recombination, and novel imaging systems to capture single cell behavior, are rapidly expanding our knowledge of the molecular mechanisms regulating all aspects of spermatogenesis. This methods chapter provides a detailed description of the system, a review of key questions chapter that have been addressed or remain unanswered thus far, and an introduction to tools and techniques available to probe each stage of spermatogenesis. PMID:24798812

  3. Measuring the micromechanical properties of embryonic tissues.

    PubMed

    Chevalier, Nicolas R; Gazguez, Elodie; Dufour, Sylvie; Fleury, Vincent

    2016-02-01

    Local mechanical properties play an important role in directing embryogenesis, both at the cell (differentiation, migration) and tissue level (force transmission, organ formation, morphogenesis). Measuring them is a challenge as embryonic tissues are small (μm to mm) and soft (0.1-10kPa). We describe here how glass fiber cantilevers can be fabricated, calibrated and used to apply small forces (0.1-10μN), measure contractile activity and assess the bulk tensile elasticity of embryonic tissue. We outline how pressure (hydrostatic or osmotic) can be applied to embryonic tissue to quantify stiffness anisotropy. These techniques can be assembled at low cost and with a minimal amount of equipment. We then present a protocol to prepare tissue sections for local elasticity and adhesion measurements using the atomic force microscope (AFM). We compare AFM nanoindentation maps of native and formaldehyde fixed embryonic tissue sections and discuss how the local elastic modulus obtained by AFM compares to that obtained with other bulk measurement methods. We illustrate all of the techniques presented on the specific example of the chick embryonic digestive tract, emphasizing technical issues and common pitfalls. The main purpose of this report is to make these micromechanical measurement techniques accessible to a wide community of biologists and biophysicists. PMID:26255132

  4. The gut microbiota and its relationship to diet and obesity

    PubMed Central

    Clarke, Siobhan F.; Murphy, Eileen F.; Nilaweera, Kanishka; Ross, Paul R.; Shanahan, Fergus; O’Toole, Paul W.; Cotter, Paul D.

    2012-01-01

    Obesity develops from a prolonged imbalance of energy intake and energy expenditure. However, the relatively recent discovery that the composition and function of the gut microbiota impacts on obesity has lead to an explosion of interest in what is now a distinct research field. Here, research relating to the links between the gut microbiota, diet and obesity will be reviewed under five major headings: (1) the gut microbiota of lean and obese animals, (2) the composition of the gut microbiota of lean and obese humans, (3) the impact of diet on the gut microbiota, (4) manipulating the gut microbiota and (5) the mechanisms by which the gut microbiota can impact on weight gain. PMID:22572830

  5. Gut Microbiota and Brain Function: An Evolving Field in Neuroscience.

    PubMed

    Foster, Jane A; Lyte, Mark; Meyer, Emeran; Cryan, John F

    2016-05-01

    There is a growing appreciation of the importance of gut microbiota to health and disease. This has been driven by advances in sequencing technology and recent findings demonstrating the important role of microbiota in common health disorders such as obesity. Moreover, the potential role of gut microbiota in influencing brain function, behavior, and mental health has attracted the attention of neuroscientists and psychiatrists. At the 29(th) International College of Neuropsychopharmacology (CINP) World Congress held in Vancouver, Canada, in June 2014, a group of experts presented the symposium, "Gut microbiota and brain function: Relevance to psychiatric disorders" to review the latest findings in how gut microbiota may play a role in brain function, behavior, and disease. The symposium covered a broad range of topics, including gut microbiota and neuroendocrine function, the influence of gut microbiota on behavior, probiotics as regulators of brain and behavior, and imaging the gut-brain axis in humans. This report provides an overview of these presentations. PMID:26438800

  6. Assessing the Human Gut Microbiota in Metabolic Diseases

    PubMed Central

    Karlsson, Fredrik; Tremaroli, Valentina; Nielsen, Jens; Bäckhed, Fredrik

    2013-01-01

    Recent findings have demonstrated that the gut microbiome complements our human genome with at least 100-fold more genes. In contrast to our Homo sapiens–derived genes, the microbiome is much more plastic, and its composition changes with age and diet, among other factors. An altered gut microbiota has been associated with several diseases, including obesity and diabetes, but the mechanisms involved remain elusive. Here we discuss factors that affect the gut microbiome, how the gut microbiome may contribute to metabolic diseases, and how to study the gut microbiome. Next-generation sequencing and development of software packages have led to the development of large-scale sequencing efforts to catalog the human microbiome. Furthermore, the use of genetically engineered gnotobiotic mouse models may increase our understanding of mechanisms by which the gut microbiome modulates host metabolism. A combination of classical microbiology, sequencing, and animal experiments may provide further insights into how the gut microbiota affect host metabolism and physiology. PMID:24065795

  7. A Hypomorphic Mutation Reveals a Stringent Requirement for the ATM Checkpoint Protein in Telomere Protection During Early Cell Division in Drosophila

    PubMed Central

    Morciano, Patrizia; Zhang, Yi; Cenci, Giovanni; Rong, Yikang S.

    2013-01-01

    Using Drosophila as a model system, we identified a stringent requirement for the conserved function of Ataxia Telangiectasia Mutated (ATM) in telomere protection during early embryonic development. Animals homozygous for a hypomorphic mutation in atm develop normally with minimal telomere dysfunction. However, mutant females produce inviable embryos that succumb to mitotic failure caused by covalent fusions of telomeric DNA. Interestingly, although the atm mutation encodes a premature stop codon, it must not have eliminated the production of the mutant protein, and the mutant protein retains kinase activity upon DNA damage. Moreover, although the embryonic phenotype of this mutation resembles that of hypomorphic mutations in the MRN complex, the function of MRN appears normal in the atm embryos. In contrast, there is a prominent reduction of the level of HipHop, an essential member of the Drosophila capping complex. How ATM functions in telomere protection remains poorly understood. The amenability of Drosophila embryos to molecular and biochemical investigations ensures that this newly identified mutation will facilitate future studies of ATM in telomere maintenance. PMID:23604076

  8. A hypomorphic mutation reveals a stringent requirement for the ATM checkpoint protein in telomere protection during early cell division in Drosophila.

    PubMed

    Morciano, Patrizia; Zhang, Yi; Cenci, Giovanni; Rong, Yikang S

    2013-06-01

    Using Drosophila as a model system, we identified a stringent requirement for the conserved function of Ataxia Telangiectasia Mutated (ATM) in telomere protection during early embryonic development. Animals homozygous for a hypomorphic mutation in atm develop normally with minimal telomere dysfunction. However, mutant females produce inviable embryos that succumb to mitotic failure caused by covalent fusions of telomeric DNA. Interestingly, although the atm mutation encodes a premature stop codon, it must not have eliminated the production of the mutant protein, and the mutant protein retains kinase activity upon DNA damage. Moreover, although the embryonic phenotype of this mutation resembles that of hypomorphic mutations in the MRN complex, the function of MRN appears normal in the atm embryos. In contrast, there is a prominent reduction of the level of HipHop, an essential member of the Drosophila capping complex. How ATM functions in telomere protection remains poorly understood. The amenability of Drosophila embryos to molecular and biochemical investigations ensures that this newly identified mutation will facilitate future studies of ATM in telomere maintenance. PMID:23604076

  9. Origin and development of neuropil glia of the Drosophila larval and adult brain: two distinct glial populations derived from separate progenitors

    PubMed Central

    Omoto, Jaison Jiro; Yogi, Puja; Hartenstein, Volker

    2015-01-01

    Glia comprise a conspicuous population of non-neuronal cells in vertebrate and invertebrate nervous systems. Drosophila serves as a favorable model to elucidate basic principles of glial biology in vivo. The Drosophila neuropil glia (NPG), subdivided into astrocyte-like (ALG) and ensheathing glia (EG), extend reticular processes which associate with synapses and sheath-like processes which surround neuropil compartments, respectively. In this paper we characterize the development of NPG throughout fly brain development. We find that differentiated neuropil glia of the larval brain originate as a cluster of precursors derived from embryonic progenitors located in the basal brain. These precursors undergo a characteristic migration to spread over the neuropil surface while specifying/differentiating into primary ALG and EG. Embryonically-derived primary NPG are large cells which are few in number, and occupy relatively stereotyped positions around the larval neuropil surface. During metamorphosis, primary NPG undergo cell death. Neuropil glia of the adult (secondary NPG) are derived from type II lineages during the postembryonic phase of neurogliogenesis. These secondary NPG are much smaller in size but greater in number than primary NPG. Lineage tracing reveals that both NPG subtypes derive from intermediate neural progenitors of multipotent type II lineages. Taken together, this study reveals previously uncharacterized dynamics of NPG development and provides a framework for future studies utilizing Drosophila glia as a model. PMID:25779704

  10. Origin and development of neuropil glia of the Drosophila larval and adult brain: Two distinct glial populations derived from separate progenitors.

    PubMed

    Omoto, Jaison Jiro; Yogi, Puja; Hartenstein, Volker

    2015-08-15

    Glia comprise a conspicuous population of non-neuronal cells in vertebrate and invertebrate nervous systems. Drosophila serves as a favorable model to elucidate basic principles of glial biology in vivo. The Drosophila neuropil glia (NPG), subdivided into astrocyte-like (ALG) and ensheathing glia (EG), extend reticular processes which associate with synapses and sheath-like processes which surround neuropil compartments, respectively. In this paper we characterize the development of NPG throughout fly brain development. We find that differentiated neuropil glia of the larval brain originate as a cluster of precursors derived from embryonic progenitors located in the basal brain. These precursors undergo a characteristic migration to spread over the neuropil surface while specifying/differentiating into primary ALG and EG. Embryonically-derived primary NPG are large cells which are few in number, and occupy relatively stereotyped positions around the larval neuropil surface. During metamorphosis, primary NPG undergo cell death. Neuropil glia of the adult (secondary NPG) are derived from type II lineages during the postembryonic phase of neurogliogenesis. These secondary NPG are much smaller in size but greater in number than primary NPG. Lineage tracing reveals that both NPG subtypes derive from intermediate neural progenitors of multipotent type II lineages. Taken together, this study reveals previously uncharacterized dynamics of NPG development and provides a framework for future studies utilizing Drosophila glia as a model. PMID:25779704

  11. Identification of motor neurons and a mechanosensitive sensory neuron in the defecation circuitry of Drosophila larvae

    PubMed Central

    Zhang, Wei; Yan, Zhiqiang; Li, Bingxue; Jan, Lily Yeh; Jan, Yuh Nung

    2014-01-01

    Defecation allows the body to eliminate waste, an essential step in food processing for animal survival. In contrast to the extensive studies of feeding, its obligate counterpart, defecation, has received much less attention until recently. In this study, we report our characterizations of the defecation behavior of Drosophila larvae and its neural basis. Drosophila larvae display defecation cycles of stereotypic frequency, involving sequential contraction of hindgut and anal sphincter. The defecation behavior requires two groups of motor neurons that innervate hindgut and anal sphincter, respectively, and can excite gut muscles directly. These two groups of motor neurons fire sequentially with the same periodicity as the defecation behavior, as revealed by in vivo Ca2+ imaging. Moreover, we identified a single mechanosensitive sensory neuron that innervates the anal slit and senses the opening of the intestine terminus. This anus sensory neuron relies on the TRP channel NOMPC but not on INACTIVE, NANCHUNG, or PIEZO for mechanotransduction. DOI: http://dx.doi.org/10.7554/eLife.03293.001 PMID:25358089

  12. Neuropeptides and the Microbiota-Gut-Brain Axis

    PubMed Central

    Holzer, Peter; Farzi, Aitak

    2015-01-01

    Neuropeptides are important mediators both within the nervous system and between neurons and other cell types. Neuropeptides such as substance P, calcitonin gene-related peptide and neuropeptide Y (NPY), vasoactive intestinal polypeptide, somatostatin and corticotropin-releasing factor are also likely to play a role in the bidirectional gut-brain communication. In this capacity they may influence the activity of the gastrointestinal microbiota and its interaction with the gut-brain axis. Current efforts in elucidating the implication of neuropeptides in the microbiota-gut-brain axis address 4 information carriers from the gut to the brain (vagal and spinal afferent neurons; immune mediators such as cytokines; gut hormones; gut microbiota-derived signalling molecules) and 4 information carriers from the central nervous system to the gut (sympathetic efferent neurons; parasympathetic efferent neurons; neuroendocrine factors involving the adrenal medulla; neuroendocrine factors involving the adrenal cortex). Apart from operating as neurotransmitters, many biologically active peptides also function as gut hormones. Given that neuropeptides and gut hormones target the same cell membrane receptors (typically G protein-coupled receptors), the two messenger roles often converge in the same or similar biological implications. This is exemplified by NPY and peptide YY (PYY), two members of the PP-fold peptide family. While PYY is almost exclusively expressed by enteroendocrine cells, NPY is found at all levels of the gut-brain and brain-gut axis. The function of PYY-releasing enteroendocrine cells is directly influenced by short chain fatty acids generated by the intestinal microbiota from indigestible fibre, while NPY may control the impact of the gut microbiota on inflammatory processes, pain, brain function and behaviour. Although the impact of neuropeptides on the interaction between the gut microbiota and brain awaits to be analysed, biologically active peptides are

  13. Scaffolding for Three-Dimensional Embryonic Vasculogenesis

    NASA Astrophysics Data System (ADS)

    Kraehenbuehl, Thomas P.; Aday, Sezin; Ferreira, Lino S.

    Biomaterial scaffolds have great potential to support efficient vascular differentiation of embryonic stem cells. Vascular cell fate-specific biochemical and biophysical cues have been identified and incorporated into three-dimensional (3D) biomaterials to efficiently direct embryonic vasculogenesis. The resulting vascular-like tissue can be used for regenerative medicine applications, further elucidation of biophysical and biochemical cues governing vasculogenesis, and drug discovery. In this chapter, we give an overview on the following: (1) developmental cues for directed differentiation of human embryonic stem cells (hESCs) into vascular cells, (2) 3D vascular differentiation in embryoid bodies (EBs), (3) preparation of 3D scaffolds for the vascular differentiation of hESCs, and (4) the most significant studies combining scaffolding and hESCs for development of vascular-like tissue.

  14. Resources for Biological Annotation of the Drosophila Genome

    SciTech Connect

    Gerald M. Rubin

    2005-08-08

    This project supported seed money for the development of cDNA and genetic resources to support studies of the Drosophila melanogaster genome. Key publications supported by this work that provide additional detail: (1) ''The Drosophila gene collection: identification of putative full-length cDNAs for 70% of D. melanogaster genes''; and (2) ''The Berkeley Drosophila Genome Project gene disruption project: Single P-element insertions mutating 25% of vital Drosophila genes''.

  15. Part II: morphological analysis of embryonic development following femtosecond laser manipulation

    NASA Astrophysics Data System (ADS)

    Kohli, V.; Elezzabi, A. Y.

    2008-02-01

    The zebrafish (Danio rerio) is an attractive model system that has received wide attention for its usefulness in the study of development and disease. This organism represents a closer analog to humans than the common invetebrates Drosophila melanogaster and Caenorhabditis elegans, making this species an ideal model for human health research. Non-invasive manipulation of the zebrafish has been challenging, owing to the outer proteinaceous membrane and multiple embryonic barriers. A novel tool capable of manipulating early cleavage stage embryonic cells would be important for future advancements in medial research and the aquaculture industry. Herein, we demonstrate the laser surgery of early cleavage stage (2-cell) blastomere cells using a range of average laser powers and beam dwell times. Since the novelty of this manipulation tool depends on its non-invasive application, we examined short- and long-term laser-induced developmental defects following embryonic surgery. Laser-manipulated embryos were reared to 2 and 7 days post-fertilization and compared to control embryos at the same developmental stages. Morphological analysis was performed using light microscopy and scanning electron microscopy. Developmental features that were examined included the antero- and dorsal-lateral whole body views of the larvae, the olfactory pit, dorsal, ventral and pectoral fins, notochord, pectoral fin buds, otic capsule, otic vesicle, neuromast patterning, and kinocilia of the olfactory pit rim and cristae of the lateral wall of the ear. Laser-manipulated embryos developed normally relative to the controls, with developmental patterning and morphology at 2 and 7 days indistinguishable from control larvae.

  16. Mad linker phosphorylations control the intensity and range of the BMP-activity gradient in developing Drosophila tissues

    PubMed Central

    Aleman, Abigail; Rios, Marlyn; Juarez, Matthew; Lee, Daniel; Chen, Annan; Eivers, Edward

    2014-01-01

    The BMP ligand Dpp, operates as a long range morphogen to control many important functions during Drosophila development from tissue patterning to growth. The BMP signal is transduced intracellularly via C-terminal phosphorylation of the BMP transcription factor Mad, which forms an activity gradient in developing embryonic tissues. Here we show that Cyclin dependent kinase 8 and Shaggy phosphorylate three Mad linker serines. We demonstrate that linker phosphorylations control the peak intensity and range of the BMP signal across rapidly developing embryonic tissues. Shaggy knockdown broadened the range of the BMP-activity gradient and increased high threshold target gene expression in the early embryo, while expression of a Mad linker mutant in the wing disc resulted in enhanced levels of C-terminally phosphorylated Mad, a 30% increase in wing tissue, and elevated BMP target genes. In conclusion, our results describe how Mad linker phosphorylations work to control the peak intensity and range of the BMP signal in rapidly developing Drosophila tissues. PMID:25377173

  17. 4-N-pyridin-2-yl-benzamide nanotubes compatible with mouse stem cell and oral delivery in Drosophila

    NASA Astrophysics Data System (ADS)

    Yadav, Jhillu S.; Lavanya, Madugula P.; Das, Pragna P.; Bag, Indira; Krishnan, Anita; Jagannadh, Bulusu; Mohapatra, Debendra K.; Pal Bhadra, Manika; Bhadra, Utpal

    2010-04-01

    p-aminobenzoic acid (PABA), a structural moiety of many commercial drugs, is self-assembled with linker alkyl side chains to form tubular nanostructures. The tubes exhibited fluorescence either intrinsic or from fluorescent molecules embedded in the wall during self-assembly. Uptake and inter-cellular delivery of the conjugated nanotubes in human cancer cells and in mouse embryonic stem cells were demonstrated by fluorescence imaging and flow cytometry. Biocompatibility, cytotoxicity and clearance were monitored both ex vivo in mouse multipotent embryonic stem cells and in vivo in adult Drosophila. Accumulation of nanotubes had no adverse effects and abnormalities on stem cell morphology and proliferation rate. A distinct distribution of two separate nanotubes in various internal organs of Drosophila interprets that accumulation of nanomaterials might be interdependent on the side chain modifications and physiological settings of cell or tissue types. Unlike carbon nanomaterials, exposure of PABA nanotubes does not produce any hazards including locomotion defects and mortality of adult flies. Despite differential uptake and clearance from multiple live tissues, the use of self-assembled nanotubes can add new dimensions and scope to the development of dual-purpose oral carriers for the fulfilment of many biological promises.

  18. Molecular lesions associated with alleles of decapentaplegic identify residues necessary for TGF/{beta}/BMP cell signaling in Drosophila melanogaster

    SciTech Connect

    Wharton, K.; Ray, R.P.; Gelbart, W.M.

    1996-02-01

    We have identified the molecular lesions associated with six point mutations in the Drosophila TGF-{beta} homologue decapentaplegic (dpp). The sites of these mutations define residues within both the pro and ligand regions that are essential for dpp function in vivo. While all of these mutations affect residues that are highly conserved among TGF-{beta} superfamily members, the phenotypic consequences of the different alleles are quite distinct. Through an analysis of these mutant phenotypes, both in cuticle preparations and with molecular probes, we have assessed the functional significance of specific residues that are conserved among the different members of the superfamily. In addition, we have tested for conditional genetic interactions between the different alleles. We show that two of the alleles are temperature sensitive for the embryonic functions of dpp, such that these alleles are not only embryonic viable as homozygotes but also partially complement other dpp hypomorphs at low temperatures. Our results are discussed with regard to in vitro mutagenesis data on other TGF-{beta}-like molecules, as well as with regard to the regulation of dpp cell signaling in Drosophila. 57 refs., 4 figs., 3 tabs.

  19. Genetic analysis of the bone morphogenetic protein-related gene, gbb, identifies multiple requirements during Drosophila development.

    PubMed Central

    Wharton, K A; Cook, J M; Torres-Schumann, S; de Castro, K; Borod, E; Phillips, D A

    1999-01-01

    We have isolated mutations in the Drosophila melanogaster gene glass bottom boat (gbb), which encodes a TGF-beta signaling molecule (formerly referred to as 60A) with highest sequence similarity to members of the bone morphogenetic protein (BMP) subgroup including vertebrate BMPs 5-8. Genetic analysis of both null and hypomorphic gbb alleles indicates that the gene is required in many developmental processes, including embryonic midgut morphogenesis, patterning of the larval cuticle, fat body morphology, and development and patterning of the imaginal discs. In the embryonic midgut, we show that gbb is required for the formation of the anterior constriction and for maintenance of the homeotic gene Antennapedia in the visceral mesoderm. In addition, we show a requirement for gbb in the anterior and posterior cells of the underlying endoderm and in the formation and extension of the gastric caecae. gbb is required in all the imaginal discs for proper disc growth and for specification of veins in the wing and of macrochaete in the notum. Significantly, some of these tissues have been shown to also require the Drosophila BMP2/4 homolog decapentaplegic (dpp), while others do not. These results indicate that signaling by both gbb and dpp may contribute to the development of some tissues, while in others, gbb may signal independently of dpp. PMID:10353905

  20. Spatial and temporal localization during embryonic and fetal human development of the transcription factor SIM2 in brain regions altered in Down syndrome.

    PubMed

    Rachidi, Mohammed; Lopes, Carmela; Charron, Giselle; Delezoide, Anne-Lise; Paly, Evelyne; Bloch, Bernard; Delabar, Jean-Maurice

    2005-08-01

    Human SIM2 is the ortholog of Drosophila single-minded (sim), a master regulator of neurogenesis and transcriptional factor controlling midline cell fate determination. We previously localized SIM2 in a chromosome 21 critical region for Down syndrome (DS). Here, we studied SIM2 gene using a new approach to provide insights in understanding of its potential role in human development. For the first time, we showed SIM2 spatial and temporal expression pattern during human central nervous system (CNS) development, from embryonic to fetal stages. Additional investigations were performed using a new optic microscopy technology to compare signal intensity and cell density [M. Rachidi, C. Lopes, S. Gassanova, P.M. Sinet, M. Vekemans, T. Attie, A.L. Delezoide, J.M. Delabar, Regional and cellular specificity of the expression of TPRD, the tetratricopeptide Down syndrome gene, during human embryonic development, Mech. Dev. 93 (2000) 189--193]. In embryonic stages, SIM2 was identified predominantly in restricted regions of CNS, in ventral part of D1/D2 diencephalic neuroepithelium, along the neural tube and in a few cell subsets of dorsal root ganglia. In fetal stages, SIM2 showed differential expression in pyramidal and granular cell layers of hippocampal formation, in cortical cells and in cerebellar external granular and Purkinje cell layers. SIM2 expression in embryonic and fetal brain could suggest a potential role in human CNS development, in agreement with Drosophila and mouse Sim mutant phenotypes and with the conservation of the Sim function in CNS development from Drosophila to Human. SIM2 expression in human fetal brain regions, which correspond to key structures for cognitive processes, correlates well with the behavioral phenotypes of Drosophila Sim mutants and transgenic mice overexpressing Sim2. In addition, SIM2-expressing brain regions correspond to the altered structures in DS patients. All together, these findings suggest a potential role of SIM2 in CNS