Drosophila melanogaster
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ABSTRACT:
PROVIDER: PRJNA269080 | ENA |
REPOSITORIES: ENA
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Project description:Wolbachia pipientis is a worldwide bacterial parasite of arthropods that infects host germline cells and manipulates host reproduction to increase the ratio of infected females, the transmitting sex of the bacteria. The most common reproductive manipulation, cytoplasmic incompatibility (CI), is expressed as embryonic death in crosses between infected males and uninfected females. Specifically, Wolbachia modify developing sperm in the testes by unknown means to cause a post-fertilization disruption of the sperm chromatin that incapacitates the first mitosis of the embryo. As these Wolbachia-induced changes are stable, reversible, and affect the host cell cycle machinery including DNA replication and chromosome segregation, we hypothesized that the host methylation pathway is targeted for modulation during cytoplasmic incompatibility because it accounts for all of these traits. Here we show that infection of the testes is associated with a 55% increase of host DNA methylation in Drosophila melanogaster, but methylation of the paternal genome does not correlate with penetrance of CI. Overexpression and knock out of the Drosophila DNA methyltransferase Dnmt2 neither induces nor increases cytoplasmic incompatibility. Instead, overexpression decreases Wolbachia titers in host testes by approximately 17%, leading to a similar reduction in CI levels. Finally, strength of CI induced by several different strains of Wolbachia does not correlate with levels of DNA methylation in the host testes. We conclude that DNA methylation mediated by Drosophila's only known methyltransferase is not required for the transgenerational sperm modification that causes CI. Genomic DNA was extracted from pooled samples of Drosophila melanogaster adult testes. One sample from Wolbachia-infected males and one from uninfected males. Bisulfite sequencing was used to determine whether Wolbachia infection affects host DNA methylation in the testes.
2014-12-03 | E-GEOD-63795 | biostudies-arrayexpress
Project description:Wolbachia pipientis is a worldwide bacterial parasite of arthropods that infects host germline cells and manipulates host reproduction to increase the ratio of infected females, the transmitting sex of the bacteria. The most common reproductive manipulation, cytoplasmic incompatibility (CI), is expressed as embryonic death in crosses between infected males and uninfected females. Specifically, Wolbachia modify developing sperm in the testes by unknown means to cause a post-fertilization disruption of the sperm chromatin that incapacitates the first mitosis of the embryo. As these Wolbachia-induced changes are stable, reversible, and affect the host cell cycle machinery including DNA replication and chromosome segregation, we hypothesized that the host methylation pathway is targeted for modulation during cytoplasmic incompatibility because it accounts for all of these traits. Here we show that infection of the testes is associated with a 55% increase of host DNA methylation in Drosophila melanogaster, but methylation of the paternal genome does not correlate with penetrance of CI. Overexpression and knock out of the Drosophila DNA methyltransferase Dnmt2 neither induces nor increases cytoplasmic incompatibility. Instead, overexpression decreases Wolbachia titers in host testes by approximately 17%, leading to a similar reduction in CI levels. Finally, strength of CI induced by several different strains of Wolbachia does not correlate with levels of DNA methylation in the host testes. We conclude that DNA methylation mediated by Drosophila's only known methyltransferase is not required for the transgenerational sperm modification that causes CI.
2014-12-03 | GSE63795 | GEO
Project description:The Drosophila-Wolbachia system is being used to study the molecular nature of the interactions between a host and a symbiont. This system offers a unique opportunity for such a study since the Drosophila genome sequence is available, several Wolbachi genomes will also be available soon and there are at least three known Wolbachia strains infecting Drosophila: a) mod+ strain that induces cytoplasmic incompatibility, b) mod- strain that cannot induce cytoplasmic incompatibility, and c) popcorn strain, a virulent strain which reduces in half the adult lifespan of Drosophila due to its massive proliferation in adult brain. The Drosophila-Wolbachia interaction manifests itself in 3 main ways; first, destruction of the CNS in infected adults, second, induction of some kind of modification or imprinting in the male germ-line resulting in an early failure in embryonic development, (cytoplasmic incompatability (CI)) and third, modification of the female germ-line resulting in resistance to modified sperm. We are interested in identifying Drosophila genes with changes in expression due to Wolbachia infection. We have generated a series of isogenic fly lines (those being used in the IGF P-element project) which we have infected with Wolbachia strains, infection is readily cured by growth on medium containing tetracycline. Thus, we have equivalent genetic background with and without the parasite. We have tested all of the transgenic lines for the level of CI and find strain-specific levels ranging from 0-50%. We also have a strain of D. simulans that shows over 95% CI. Plan: For our initial experiments we wish to make 4 comparisons, in all cases 2 day old males will be collected and for each comparison we will isolate 3 independent biological replicates: Melanogaster no CI [tet] x Melanogaster no CI [+wol] Melanogaster high CI [tet] x Melanogaster high CI [+wol] We will therefore identify genes with changed expression levels in the male upon Wolbachia infection by comparing the melanogaster strains with high or no CI in the presence of tetracycline and Wolbachia. We also hope to identify similar genes in simulans (where we expect the magnitude of the effect to be larger), differences between melanogaster and simulans are controlled for in the mel v sim comparison.
2004-05-07 | E-FLYC-3 | biostudies-arrayexpress
Project description:Use of the bacterium Wolbachia is an innovative new strategy designed to break the cycle of dengue transmission. There are two main mechanisms by which Wolbachia could achieve this: by reducing the level of dengue virus in the mosquito and/or by shortening the host mosquito's lifespan. However, although Wolbachia shortens the lifespan, it also gives a breeding advantage which results in complex population dynamics. This study focuses on the development of a mathematical model to quantify the effect on human dengue cases of introducing Wolbachia into the mosquito population. The model consists of a compartment-based system of first-order differential equations; seasonal forcing in the mosquito population is introduced through the adult mosquito death rate. The analysis focuses on a single dengue outbreak typical of a region with a strong seasonally-varying mosquito population. We found that a significant reduction in human dengue cases can be obtained provided that Wolbachia-carrying mosquitoes persist when competing with mosquitoes without Wolbachia. Furthermore, using the Wolbachia strain WMel reduces the mosquito lifespan by at most 10% and allows them to persist in competition with non-Wolbachia-carrying mosquitoes. Mosquitoes carrying the WMelPop strain, however, are not likely to persist as it reduces the mosquito lifespan by up to 50%. When all other effects of Wolbachia on the mosquito physiology are ignored, cytoplasmic incompatibility alone results in a reduction in the number of human dengue cases. A sensitivity analysis of the parameters in the model shows that the transmission probability, the biting rate and the average adult mosquito death rate are the most important parameters for the outcome of the cumulative proportion of human individuals infected with dengue.
2020-03-20 | MODEL2003160002 | BioModels
Project description:Transcriptional regulation of Culex pipiens mosquitoes by Wolbachia influences cytoplasmic incompatibility
| PRJEB4607 | ENA
Project description:Wolbachia endosymbionts are widespread intracellular, maternally inherited bacteria which manipulate the host to favour their spread through a population. Cytoplasmic incompatibility (CI) and viral suppression are two such manipulations driven by uncharacterised mechanisms. To gain insight into potential molecular mechanisms responsible for these effects, we performed the first in-depth proteomic characterisation of the host response to Wolbachia infection. We find that the presence of the Wolbachia wMelPop in Aedes aegypti mosquito cells alters levels of proteins involved in cell cycle control, DNA replication, autophagy, vesicular trafficking, iron homeostasis, amino acid degradation, purine metabolism, lipid metabolism and immunity. The majority of the cell cycle/DNA replication proteins were downregulated in the presence of Wolbachia, in particular, a member of the anoctamin family was strongly down regulated which may be related to the chromosomal segregation defects observed in CI crosses. We found clear evidence for perturbed lipid metabolism, Wolbachia infected cells expressed higher levels of Apolipoprotein D and the cholesterol efflux transporter ABCA1, while the LDL receptor and fatty acid synthase were downregulated. ABCA1 was also upregulated at the mRNA level in adult Wolbachia infected Aedes aegypti mosquitoes. Wolbachia therefore perturbs cholesterol homeostasis causing the host cell to respond to an apparent cholesterol excess which may contribute to viral inhibition.
2017-09-19 | PXD003429 | Pride
Project description:Dnmt2 and NSun2 are (cytosine-5) RNA methyltransferases. Using CRISPR/Cas9 we created null mutations in Dnmt2 and NSun2 genes in Drosophila melanogaster. We also ectopically expressed a wild type and catalytically inactive Dnmt2 form in the Dnmt2 mutant background. RNA bisulfite sequencing was used to follow RNA methylation at partical tRNA substrates.
2018-01-16 | GSE109133 | GEO
Project description:Globally invasive Aedes aegypti mosquitoes disseminate numerous arboviruses that impact human health. One promising method to control Ae. aegypti populations is transinfection with the intracellular bacterium Wolbachia pipientis, a symbiont that naturally infects ~40-52% of insects but is normally absent from Ae. aegypti. Transinfection of Ae. aegypti with the wMel Wolbachia strain induces cytoplasmic incompatibility (CI), allowing infected individuals to rapidly invade native populations. Further, wMel Wolbachia-infected females display refractoriness to medically relevant arboviruses. Thus, wMel Wolbachia-infected Ae. aegypti are being released in several areas to replace native populations, thereby suppressing disease transmission by this species. Wolbachia is reported to have minimal effects on Ae. aegypti fertility, but its influence on other reproductive processes is unknown. Female insects undergo several post-mating physiological and behavioral changes required for optimal fertility. Post-mating responses (PMRs) in female insects are typically elicited by receipt of male seminal fluid proteins (SFPs) transferred with sperm during mating, but can be modified by other factors, such as adult age, nutritional status, and microbiome composition. To assess how Wolbachia infection influences Ae. aegypti female PMRs, we collected wMel Wolbachia-infected Ae. aegypti from the field in Medellín, Colombia and introduced the bacterium into our laboratory strain. We found that Wolbachia influences female fecundity, fertility, and re-mating incidence. Further, we observed that Wolbachia significantly extends longevity of virgin females. Changes in female PMRs are not due to defects in sperm transfer by infected males, or sperm storage by infected females. Using proteomic methods to examine the seminal proteome of infected males, we found that Wolbachia infection has a moderate effect on SFP composition. However, we identified 125 Wolbachia proteins that are paternally transferred to females by infected males. Surprisingly, the CI factor proteins (Cifs), were not detected in the ejaculates of Wolbachia-infected males. Our findings indicate that Wolbachia infection of Ae. aegypti alters female post-mating responses, potentially influencing control programs that utilize Wolbachia-infected individuals.
2023-10-24 | PXD043965 | Pride
Project description:Dnmt2 is a widely conserved protein, which is closely related to eukaryotic DNA methyltransferases. However, Dnmt2 shows a robust tRNA methyltransferase activity and only limited activity towards DNA. Interestingly, a recent study has provided evidence for a biologically important function of Dnmt2-dependent DNA methylation in the blood fluke Schistosoma mansoni, which seemed to contradict the weak activity of the enzyme in other organisms. We now used whole-genome bisulfite sequencing to comprehensively analyze the methylome of adult worms and could not detect any evidence for biologically relevant DNA methylation patterns. We also characterized the methylome of Drosophila melanogaster embryos and did not find any evidence for DNA methylation. Unconverted cytosine residues were detectable only at very low levels and shared many attributes with bisulfite deamination artifacts. Our results thus strongly argue against a DNA methyltransferase activity of Dnmt2 and suggest that Dnmt2-dependent phenotypes are caused by reduced tRNA methylation. Whole genome methylation analysis of D. melanogaster. Two samples were analyzed, one sample containing DNA from WT embryos, one sample containing DNA from Dnmt2-/- embryos.
2013-05-06 | E-GEOD-39996 | biostudies-arrayexpress
Project description:Dnmt2 is a widely conserved protein, which is closely related to eukaryotic DNA methyltransferases. However, Dnmt2 shows a robust tRNA methyltransferase activity and only limited activity towards DNA. Interestingly, a recent study has provided evidence for a biologically important function of Dnmt2-dependent DNA methylation in the blood fluke Schistosoma mansoni, which seemed to contradict the weak activity of the enzyme in other organisms. We now used whole-genome bisulfite sequencing to comprehensively analyze the methylome of adult worms and could not detect any evidence for biologically relevant DNA methylation patterns. We also characterized the methylome of Drosophila melanogaster embryos and did not find any evidence for DNA methylation. Unconverted cytosine residues were detectable only at very low levels and shared many attributes with bisulfite deamination artifacts. Our results thus strongly argue against a DNA methyltransferase activity of Dnmt2 and suggest that Dnmt2-dependent phenotypes are caused by reduced tRNA methylation.
2013-05-06 | GSE39996 | GEO