ABSTRACT: Adults heterozygous for the hi2217 retroviral insertion within the HAI locus (Mathias et al 2007 JCS) were in-crossed for RNA from hi2217 mutants and corresponding WT siblings. Adults heterozygous for the hi1520 retroviral insertion within the Clint1 locus (Dodd et al, 2009) were in-crossed for RNA from hi1520 mutants and corresponding WT siblings. Both hi2217 and hi1520 are mutants with epidermal defects and showing symptoms of chronic inflammation. In this study we aimed to compare the RNA expression changes between Wild-type siblings (a non-inflammatory status) and homozygous mutants (a chronic inflammatory status) for each mutant background (hi2217 and hi1520). Pools of 30-50 zebrafish embryos of WT siblings and hi2217 or hi1520 mutants were collected for RNA isolation. RNA from the hi2217 mutant embryos or hi1520 mutant embryos (test samples)was labelled with Cy5 and hybridized against Cy3-labelled RNA from the corresponding WT sibling embryos (reference samples) . These experiments were performed in biological triplicate.
Project description:MyD88 is an adaptor protein in Toll-like receptor and interleukin 1 receptor mediated signaling pathways that plays an essential role in activation of immune responses following pathogen recognition. We investigate that role in the zebrafish embryo model by using a zebrafish mutant line that contains a premature stop condon in the gene encoding MyD88, leading to a truncated protein that lacks domains important for its normal function. We infected these MyD88 mutants and wildtype individuals with Salmonella typhimurium and Edwardsiella tarda to compare the resulting immune response by transcriptome profiling on total RNA isolated from single embryos. The data derived from these microarray experiments confirms the vital role of MyD88 in pathogen recognition and provides many leads for further research. This microarray study was designed to determine the effect of a truncation of the MyD88 protein on the innate immune response of zebrafish embryos during infection with Salmonella typhimurium and Edwardsiella tarda. Embryos used in this study are derived from an incross between parents heterozygous for the mutation. Both homozygous mutants and their wildtype siblings were selected by genotyping after being injected with the bacteria or PBS as control. RNA was isolated from single embryos and each treatment group consisted of three embryos: (1) Homozygous mutants injected with PBS 8 hours post infection (hpi), (2) wildtype siblings injected with PBS 8hpi, (3) S. typhimurium-infected homozygous mutants 8hpi, (4) S. typhimurium-infected wildtype siblings 8hpi, (5) Homozygous mutants injected with PBS 8 hours post infection (hpi) (E.tarda control), (6) wildtype siblings injected with PBS 8hpi (E. tarda control), (7) E. tarda-infected homozygous mutants 8hpi, (8) E. tarda-infected wildtype siblings 8hpi. Embryos were grown at 28.5M-bM-^@M-^S30M-BM-0C in egg water and manually dechorionated at 24 hours post fertilization (hpf). Subsequently, embryos were infected at 28 hpf by micro-injecting 200 colony forming units (CFU) of S. typhimurium SL1027 or E. Tarda FL-F60, or were mock-injected with buffer as a control. After injections embryos were transferred into fresh egg water and incubated for 8 h or 4 days at 28M-BM-0C. After the incubation period, single embryos were snap-frozen in liquid nitrogen and RNA was isolated for microarray analysis. All treatment groups were analyzed using a common reference approach.
Project description:Transcriptional profiling of hdac1 mutant zebrafish in comparison to their sibling embryos. Embryos resulting from a cross between heterozygous hdac1 mutant zebrafish (hi1618/+) where cultured together then mutants separated from the siblings one the basis of phenotype and RNA extracted from the two groups at 27hpf was compared in a two-colour hybridisation. Two-condition experiment, hdac1 mutants vs. sibling. Biological replicates: 2 (separate mating) Technical replicates: 4 (2 of which are dye-swap)
Project description:MyD88 is an adaptor protein in Toll-like receptor and interleukin 1 receptor mediated signaling pathways that plays an essential role in activation of immune responses following pathogen recognition. We investigate that role in the zebrafish embryo model by using a zebrafish mutant line that contains a premature stop condon in the gene encoding MyD88, leading to a truncated protein that lacks domains important for its normal function. We infected these MyD88 mutants and wildtype individuals with S Mycobacterium marinum to compare the resulting immune response by transcriptome profiling on total RNA isolated from single embryos. Autophagy regulator dram1 was identified as one of the MyD88-dependent genes. This microarray study was designed to determine the effect of a truncation of the MyD88 protein on the innate immune response of zebrafish embryos during infection with Mycobacterium marinum. Embryos used in this study are derived from an incross between parents heterozygous for the mutation. Both homozygous mutants and their wildtype siblings were selected by genotyping after being injected with the bacteria or PBS as control. RNA was isolated from single embryos at 4 days post infection (4 dpi) and each treatment group consisted of three embryos: (1) Homozygous mutants mock-injected with PBS/2%PVP 4 dpi, (2) wildtype siblings mock-injected with PBS/2%PVP 4dpi, (3) M. marinum-infected homozygous mutants 4dpi, (4) M. marinum-infected wildtype siblings 4dpi. Embryos were grown at 28.5M-bM-^@M-^S30M-BM-0C in egg water and manually dechorionated at 24 hours post fertilization (hpf). Subsequently, embryos were infected at 28 hpf by micro-injecting 200 colony forming units (CFU) of Mycobacterium marinum Mma20 bacteria into the caudal vein, or were mock-injected with buffer (PBS/2%PVP) as a control. After injections embryos were transferred into fresh egg water and incubated for 4 days at 28M-BM-0C. After the incubation period, single embryos were snap-frozen in liquid nitrogen and RNA was isolated for microarray analysis. The treatment groups were analyzed using a common reference approach.
Project description:Mutants of zebrafish affected in neural crest development (cls/sox10, hps/erbb3, low/tfap2a, nac/mitfa, pfe/csfr1, shd/ltk, spa/kit tdo/trpm7) were compared to their wild type siblings or to wild type controls during development at 28hpf, 48hpf and 4 dpf.
Project description:We use the zebrafish embryo model to study the innate immune response against Staphylococcus epidermidis. Therefore, we injected S. epidermidis (and three controls groups) into the yolk at 2 hpf and samples at mutiple timepoints. Gene expression profiles were obtained at 6, 30, 54, 78, 102 and 126 hpi by microarrays. The results show that the gram-positive bacterium S. epidermidis induces a late immune response with a strong response at 102 hpi. This microarray study was designed to determine the gene expression profile during infection with Staphylococcus epidermidis. RNA was isolated from groups of embryos (20) at 6 timepoints during the infection. Wildtypes zebrafish embryos were micro-injected into the yolk (2hpf) with (1) 20 CFU of S. epidermdis O-47 mCherry bacteria suspended in PVP (Polyvinylpyrrolidone), (2) mock-injected with PVP as a control, (3) Needle insertion as control, (4) Non-injected as a control. After injections embryos were transferred into fresh egg water and incubated at 28M-BM-0C. At 8 hpf (6 h post infection), 32 hpf (30 h post infection), 56 hpf (54 h post infection), 80 hpf (78 h post infection), 104 hpf (102 h post infection) or 128 hpf (126 h post infection) twenty embryos per treatment group were snap-frozen in liquid nitrogen, and total RNA was isolated using TRIZOL reagent. All treatment groups were analyzed using a common reference approach.
Project description:The Spi1/ Pu.1 transcription factor plays a crucial role in myeloid cell development across many species. Several Spi1 target genes have been identified so far, yet the Spi1-dependent gene group remains largely unknown. To identify novel genes downstream of Spi1 we employed a microarray strategy using zebrafish embryos. We established the gene group down-regulated upon spi1 knockdown while simultaneously enriched in FACS-sorted embryonic myeloid cells of a spi1:GFP transgenic line, thus representing putative myeloid-specific Spi1 target genes. This gene group contained all previously identified Spi1-dependent zebrafish genes, confirming the validity of the approach, as well as novel immune-related genes. Colocalization studies with neutrophil and macrophage markers revealed that genes cxcr3.2, mpeg1, ptpn6 and mfap4 were expressed specifically in early embryonic macrophages. The analysis of adult zebrafish hematopoietic tissue showed that genes mfap4 and mpeg1 remained macrophage specific within the myeloid fraction throughout zebrafish life. We also demonstrated that gene cxcr3.2, coding for chemokine receptor 3.2, functions in macrophage migration to the site of bacterial infection. These results establish a myeloid-specific gene group dependent on Spi1 in zebrafish and identify novel early macrophage-specific marker genes, which will facilitate further studies of macrophage development and innate immune function. Zebrafish strains Zebrafish (Danio rerio) were handled in compliance with the local animal welfare regulations and maintained according to standard protocols (http://ZFIN.org). The spi1-gfp transgenic line used in this study (Pu1-lynEGFP, a gift from Franscesca Peri, EMBL, Heidelberg) contains 4 kb of spi1/pu.1 promoter sequence driving expression of membrane-targeted EGFP. Morpholino knock-down experiments Morpholino oligonucleotides (Gene Tools) were diluted to required concentration in 1x Danieu’s buffer (58 mM NaCl, 0.7 mM KCl, 0.4 mM MgSO4, 0.6 mM Ca(NO3)2, 5.0 mM HEPES; pH 7.6) containing 1% Phenol red (Sigma) and approximately 1 nl was injected into the 1-2 cell stage embryo using a Femtojet injector (Eppendorf). Embryo dissociation and FACS (Fluorescent activated cell sorting) Dissociation of embryos was performed according to Covassin et al. 30. In short, ~300 embryos of spi1:GFP line at 28 hpf were dechorionated by pronase treatment, rinsed in calcium free Ringer solution, followed by digestion with 0.25% trypsin. The obtained cell suspension was centrifuged, rinsed with PBS and resuspended in Leibovitz medium L15 without phenol red, 1% fetal calf serum, 0.8mM CaCl2, penicillin 50 U/ml and streptomycin 0.05 mg/ml. The single cell suspension was subject to FACS at room temperature using a FACSAria (Becton Dickinson) with the BD FACSDiva software version 5.0.3 and a Coherent Sapphire solid state laser 488 nm with 13 mW power. The GFP+ and GFP- cell fractions were collected separately into L15 medium supplemented with 0.8 mM CaCl2, 10% fetal calf serum and penicillin 50 U/ml and streptomycin 0.05 mg/ml. The standard yield from circa 300 embryos was approximately 2 x 105 GFP+ cells. Microarray experiment design and analysis Embryos injected either with 1 mM Pu1 morpholino19 or 1 mM Standard Control morpholino were harvested at 28 hours post fertilization (hpf). As a control, embryos injected with an equal volume of 1% Phenol red in Danieu’s buffer (1xPR/D) were used. Pools of 20-30 embryos were collected. RNA samples from spi1 morphants and standard control morphants were labelled with Cy5 and hybridized against a Cy3-labelled common reference (a mixture of all samples injected with 1xPR/D). This experiment was performed in triplicate. FACS sorted spi1-GFP zebrafish embryos at 28hpf were analyzed as follows: the RNA of GFP-positive fraction was labelled with Cy5 and hybridized against a Cy3-labelled RNA of corresponding GFP-negative fraction of cells from the same pool of embryos. This experiment was performed in duplicate. RNA isolation, synthesis of amino allyl labeled aRNA, coupling of Cy3 and Cy5 dyes, and hybridization conditions were as described31. Microarray analysis was performed using custom-designed 44k Agilent chips (platform accession number in GEO: GPL7735) described elsewhere 31. Microarray data were processed and analyzed as described 31. Significance cut-offs for differentially expressed probe sequences were set at 1.2 fold change at P <10-2.
Project description:Pathogenic mycobacteria have the ability to survive within macrophages and persist inside granulomas composed of host immune cells. The complex host-pathogen interactions that determine the outcome of a mycobacterial infection process result in marked alterations of the host gene expression profile. Here we used the zebrafish model to investigate the specificity of the host response to infections with two mycobacterium strains that give distinct disease outcomes: an acute disease with early lethality or a chronic disease with granuloma formation, caused by Mycobacterium marinum strains Mma 20 and E11, respectively. We performed a microarray study of different stages of disease progression in adult zebrafish and found that the acute and the chronic strains evoked partially overlapping host transcriptome signatures, despite that they induce profoundly different disease phenotypes. Both strains affected many signaling cascades, including Wnt and Tlr pathways. Interestingly, the strongest differences were observed at the initial stage of the disease. The immediate response to the acute strain was characterized by higher expression of genes encoding MHC class I proteins, matrix metalloproteinases, transcription factors, cytokines and other common immune response proteins. In contrast, small GTPase and histone gene groups showed higher expression in response to the chronic strain. We also found that nearly 1,000 mycobacterium-responsive genes overlapped between the expression signatures of infected zebrafish adults and embryos at different stages of granuloma formation. Since adult zebrafish possess an adaptive immune system similar to mammals and zebrafish embryos rely solely on innate immunity, this overlap indicates a major contribution of the innate component of the immune system in the response to mycobacterium infection. Taken together, our comparison of the transcriptome responses involved in acute versus chronic infections and in the embryonic versus adult situation provides important new leads for investigating the mechanism of mycobacterial pathogenesis. Zebrafish were handled in compliance with the local animal welfare regulations and maintained according to standard protocols (http://ZFIN.org). Infection experiments were approved by the local animal welfare committee (DEC) of the VU University medical center and of Leiden Univeristy. Infection experiments with adult fish were performed on young males selected from a wild type laboratory-breeding colony and acclimated to their new environment for one week in a quarantine area. These fish were kept at 28ËC on a 12:12 h light/dark rhythm throughout the experiment. Groups of 30 fish, infected with the same dose and strain of mycobacteria, were kept in small fish tanks (10 l) with their own separate filtering system (Eheim Ecco). Zebrafish were inoculated intraperitoneally as previously described (Meijer et al., 2004) with approximately 10000 bacteria or with phosphate-buffered saline (PBS) as a control. For the acute infection study with E11 and Mma20 strains, 3 fish per group were sacrificed at 1 and 6 days post infection (dpi) and used for microarray analysis. For comparison with the end stage of chronic E11 infection we used RNA samples from our previously published chronic infection study (Meijer et al., 2005; control fish c2 and infected fish i2) and additional RNA samples (2 controls, 2 infected) from a similar infection experiment. All chronically infected fish showed overt signs of fish tuberculosis, including lethargy and skin ulcers. Histological examination of fish from the same experiments confirmed that the pathology of infected fish corresponded to fish tuberculosis (Van der Sar et al., 2004) and that no characteristics of the disease were present in the control fish. Infection experiments at the embryonic stage were performed using mixed egg clutches from different pairs of AB strain zebrafish. Embryos were grown at 28,5 -30 °C in egg water (60µg/ml Instant Ocean see salts) and for the duration of bacterial injections embryos were kept under anaesthesia in egg water containing 0.02% buffered 3-aminobenzoic acid ethyl ester (tricaine, Sigma). Embryos were staged at 28 hours post fertilization (hpf) by morphological critera (Kimmel et al.) and approximately 50 cfu of E11 bacteria were injected into the caudal vein close to the urogenital opening. As a control an equal volume of PBS was likewise injected. Infection experiments were carried out in triplicate on separate days and pools of 15-20 embryos were taken at 2, 24 and 120 hours post infection (hpi).
Project description:Characterization of the zebrafish embryonic host response to systemic bacterial infection with Salmonella typhimurium wild type strain (SL1027) and its isogenic LPS O-antigen mutant Ra (SF1592) by means of a time-resolved global expression analysis. All infection experiments were performed using mixed egg clutches from three tanks of AB strain zebrafish. Embryos were staged at 27 hours post fertilization (hpf) by morphological criteria (Kimmel et al., 1995) and approximately 250 cfu of DsRed expressing S. typhimurium wt and Ra mutant bacteria were injected into the caudal vein close to the urogenital opening. As a control an equal volume of PBS was likewise injected. Injections were controlled using a Leica MZ Fluo 3 stereomicroscope with epifluorescence attachment together with a Femtojet microinjector (Eppendorf) and a micromanipulator with pulled microcapillary pipettes. Pools of 20-40 embryos were collected at 2, 5, 8 and 24 hours post infection (hpi). For the microarray analysis, the whole infection procedure was preformed in triplicate on separate days. The triplicates are marked A,B and C. The order of injecting wt bacteria, Ra bacteria and PBS control was randomized in the different experiments. The general reference sample is a mixture of all RNA samples from this infection study and it is named Common Reference (CR).
Project description:In this study we analyzed the zebrafish embryonic host response induced by E. tarda (FL6-60) immersion. The E. tarda induced transcriptome profile was compared to those induced by either E. coli or Pseudomonas aeruginosa immersion using the same experimental setup. All infection experiments were performed using mixed egg clutches of Albino strain zebrafish. At 24 hpf embryos were dechorionated using 2mg/ml pronase and left to recover for one hour in egg water. Subsequently embryos were immersed in a bacterial suspension (E. tarda (1E8 CFU/ml), E. coli (1E8 CFU/ml), Pseudomonas aeruginosa PAO1 (1E9 CFU/ml) or P. aeruginosa PA14 (1E9 CFU/ml)) and incubated for 5 hours at 28 ˚C. After the incubation period the embryos were snap-frozen in liquid nitrogen. All treatment groups were analyzed using a common reference approach.