Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Single Feature Polymorphism (SFP) Data from Drosophila Genomic DNA

ABSTRACT: Natural populations of the fruit fly, Drosophila melanogaster, segregate genetic variation that leads to cardiac disease phenotypes. Drosophila is well-known as a model for studying the mechanisms by which human disease genes cause pathology, including heart disease, but it is less well appreciated that they may also model the genetic architecture of disease, since flies presumably also have diseases that have a genetic basis. It is reasoned that most of these aberrant inbred line effects would be due to capture of rare variants of large effect as homozygotes, allowing the variants to be mapped rapidly using contemporary genomic approaches. In order to map the genetic variants in flies, we used single feature polymorphism (SFP) analysis to contrast the genome-wide genotype frequencies between pools of flies with aberrant and normal heart phenotype. SFP analysis is an indirect method for genome-wide genotyping that utilizes differential hybridization of genomic DNA to probes on a DNA chip that was initially designed for gene expression profiling, but can be used for species where genotyping chips are not available. DNA was prepared from three independent pools of 15 flies for each of the two types, as well as from the two parental lines. The samples were sheared and labeled with biotin, then hybridized to Affymetrix Drosophila expression microarray chips. Mismatch hybridization, namely a significant difference in the hybridization intensity between the parental lines, was detected from all perfect match (PM) probes, located in over 9,000 probes with an estimated False Discovery Rate of 11%.

ORGANISM(S): Drosophila melanogaster

SUBMITTER: zhi zhang

PROVIDER: E-GEOD-45123 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:Tsetse flies (Glossina spp.) are major vectors of African trypanosomes, causing either Human or Animal African Trypanosomiasis (HAT or AAT). Several approaches are developed to control the disease among which the anti-vector Sterile Insect Technique. Another approach in the frame of anti-vector strategies could consist in controlling the fly’s vector competence which needs identifying factors (genes, proteins, biological pathways, …) involved in this process. The present work aims to verify whether protein candidates identified under experimental controlled conditions on insectary-reared tsetse flies have their counterpart in field-collected flies. Glossina palpalis palpalis flies naturally infected with Trypanosoma congolense were sampled in two HAT/AAT foci in Southern Cameroon. After dissection, the proteome from guts of parasite-infected flies were compared to that from uninfected flies in order to identify quantitative and/or qualitative changes associated to infection. A total of 3291 proteins were identified of which 1818 could be quantified. The comparative analysis allowed identifying 175 proteins with significant decreased abundance in infected as compared to uninfected flies, while 61 proteins displayed increased abundance. Among the former are RNA binding proteins, kinases, actin, ribosomal proteins, endocytosis proteins, oxido-reductases, as well as proteins that are unusually found such as tsetse salivary proteins (Tsal) or Yolk proteins. Among the proteins with increased abundance are fructose-1,6-biphosphatase, serine proteases, membrane trafficking proteins, death proteins (or apoptosis proteins), and SERPINs (inhibitor of serine proteases, enzymes considered as trypanosome virulence factors) that displayed highest increased abundance. Sodalis, Wiggleswothia and Wolbachia proteins are strongly under-represented, particularly when compared to data from similar experimentation conducted under controlled conditions on T. brucei gambiense infected (or uninfected) G. palpalis gambiensis insectary reared flies. Comparing the overall recorded data, 364 proteins identified in gut extracts from field flies were shown to have a homologue in insectary flies. Discrepancies between the two studies may arise from differences in the species of studied flies and trypanosomes as well as in differences in environmental conditions in which the two experiments were carried out. Finally, the present study together with former proteomic and transcriptomic studies on the secretome of trypanosomes, on the gut extracts from insectary reared and on field collected tsetse flies, provide a pool of data and information on which to draw in order to perform further investigations on, for example, mammal host immunization or on fly vector competence modification via para-transgenic approaches.

Project description:The population structure of Toxoplasma gondii includes three highly prevalent clonal lineages, types I, II, and III, which differ greatly in virulence in the mouse model. Previous studies have implicated a family of serine threonine protein kinases found in rhoptries (ROPs) as important in mediating virulence differences between types I vs. III and II vs. III. Here, we explored the genetic basis of differences in virulence between the highly virulent type I lineage and moderately virulent type II based on a new genetic cross and linkage mapping. Genome-wide association revealed a single quantitative trait locus controls the > 4 log difference in lethality between these strains. Neither ROP16 nor ROP18, previously implicated in virulence differences in T. gondii, were found to contribute to differences between types I and II. Instead, the major virulence locus contained a cluster of pseudokinases denoted as rhoptry protein 5 (ROP5); this locus contains a tandem cluster of polymorphic alleles that differed in expression levels between strains. ROP5 alleles contained only part of the catalytic triad of canonical S/T kinases, and consistent with this they lack demonstrable kinase activity in vitro. Genetic disruption of the rop5 locus in the type I lineage lead to a > 5 log increase in the lethal dose, and surviving mice developed lasting immunity and were protected from an otherwise lethal challenge. These findings reveal that amplification of a polymorphic cluster of pseudokinases plays an important role in pathogenesis of toxoplasmosis in the mouse model. We used a new genotyping protocol based on hybridization of parental and recombinant progeny genomic DNA (gDNA) to Affymetrix gene arrays constructed for T. gondii (http://ancillary.toxodb.org/docs/Array-Tutorial.html). We identified 1,603 single feature polymorphisms (SFP) based on probes that successfully discriminated perfect match (type II) from mismatch (type I) hybridization across all clones and provided reliable SFP markers for this cross.

Project description:Stem cells reside in a specialized microenvironment, called niche, which provides essential signals controlling stem cell behavior. Proper niche architecture is a key for normal stem cell function, yet only few upstream regulators are known. Here we report that the Hox transcription factor Abd-B, active in pre-meiotic spermatocytes, affects niche positioning in the Drosophila testis by regulating integrin localization in differentiated somatic cyst cells. Loss of Abd-B results in cell non-autonomous effects within the niche including centrosome misorientation in germline stem cells (GSCs) and reduced GSC divisions in larval testis, leading to a dramatic reduction of pre-meiotic stages in adult testes. By identifying Abd-B binding regions throughout the genome, we find that Abd-B mediates its effects on niche function by directly controlling at multiple levels the localization and thus signaling activity of the Sevenless (Sev) ligand, Bride of Sevenless (Boss), via its direct targets src42A and sec63. In sum, our data show for the first time that Abd-B through local signaling provides positional cues for integrin localization, which is critical for niche localization and architecture, and ensures proper niche function and GSC activity. DamID (DNA adenine methyltransferase identification) method was used to identify direct Abd-B target genes in the Drosophila 3rd instar larval testis Dam was fused to the N terminus of Abd-B and transgenic flies were generated. For identifying Abd-B targets in the Drosophila testis the fusion protein was expressed from the uninduced minimal Hsp70 promoter of the UAS vector pUAST (Brand and Perrimon, 1993). As a control for nonspecific Dam activity, transgenic flies expressing the Dam alone were used (Choksi et al., 2006). Subsequently, genomic DNA was extracted from 3rd instar larval testes, expressing either the Dam-Abd-B fusion protein or the Dam protein alone using a specific protocol (Tolhuis et al., 2011); and van Steensel personal communication). Two individual replicates, for Dam-AbdB and Dam alone, have been generated. Following a methylation-sensitive DNA digestion and PCR amplification, DNA fragments from Dam-Abd-B and control DNA were labeled and hybridized to genomic Affymetrix arrays in duplicates (Protocol available at M-bM-^@M-^\www.flychip.org.ukM-bM-^@M-^]).

Project description:Although radiation effects have been extensively studied, the biological effects of low-dose radiation (LDR) are controversial. This study investigates LDR-induced alterations in locomotive behavior and gene expression profiles of Drosophila melanogaster. We measured locomotive behavior using larval pupation height and rapid iterative negative geotaxis (RING) assay after exposure to 0.1 Gy gamma-radiation (dose rate of 16.7 mGy/h). We also observed chronic LDR effects on development (pupation and eclosion rates) and longevity (life span). To identify chronic LDR effects on gene expression, we performed whole-genome expression analysis using gene-expression microarrays, and confirmed the results using quantitative real-time PCR. Pupation height was significantly higher after LDR treatment at the first larval instar. Locomotive behavior of male flies was significantly greater approximately 3M-BM--5 weeks after LDR, but pupation and eclosion rates and life spans were not significantly different. Genome-wide expression analysis identified 344 genes that were differentially expressed in irradiated larvae compared with those of controls. We identified several genes belonging to larval behavior functional groups such as locomotive behavior and oxidation reduction, and genes involved in conventional functional groups modulated by irradiation such as defense response, sensory and perception. Four candidate genes were confirmed as differentially expressed genes in irradiated larvae using qRT-PCR. These data suggest that LDR stimulates locomotion-related genes, and these genes can be used as potential markers for LDR. Eggs were collected from 5-day-old female flies and cultivated for 24 h on standard medium. Then, twenty larvae were manually selected and seeded on fresh standard medium in a new vial. After transfer, the experimental group of first-instar larvae was immediately irradiated with chronic gamma-radiation at a dose rate of 16.7 mGy/h. After treatment, gamma-irradiated flies and non-irradiated control flies were maintained in the same incubator at 25degC.

Dataset Information

Single Feature Polymorphism (SFP) Data from Drosophila Genomic DNA

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets