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ABSTRACT:
PROVIDER: PRJNA795146 | ENA |
REPOSITORIES: ENA
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Project description:A chromosome-level genome assembly of the parasitoid wasp, Cotesia glomerata (Hymenoptera: Braconidae)
| PRJEB45226 | ENA
Project description:The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and the viruses it transmits, are a major constraint to vegetable crops, worldwide. Although the whitefly is usually controlled using chemical pesticides, biological control agents constitute an important component in integrated pest management programs. One of these agents is the wasp Eretmocerus mundus (Mercet) (Hymenoptera: Aphelinidae). E. mundus lays its egg on the leaf underneath the pupa of B. tabaci. First instars of the wasp hatch and penetrate the whitefly larvae. Initiation of parasitization induces the host to form a cellular capsule around the parasitoid. Around this capsule, epidermal cells multiply and thick layers of cuticle are deposited. The physiological and molecular processes underlying B. tabaci-E. mundus interactions have not been investigated so far. We have used a cDNA microarray containing 6,000 expressed sequence tags (ESTs) from the whitefly genome to study the parasitoid-whitefly interaction. We compared RNA samples collected across two time points of the parasitization process: when the parasitoid first instar started the penetration process and once it had fully penetrated the host. The results clearly indicated that genes known to be part of the defense pathways described in other insects are also involved in the response of B. tabaci to parasitization by E. mundus. Some of the responses observed included the repression of a serine protease inhibitor (serpin) and the induction of a melanization cascade. A second set of genes that strongly responded to parasitization included bacterial genes encoded by whitefly symbionts. Quantitative real-time PCR and FISH analyses showed that proliferation of Rickettsia, a facultative secondary symbiont, was strongly induced following the initiation of the parasitization process, a result that supported previous reports suggesting that endosymbionts may be involved in the insect host resistance to various environmental stresses. This is the first study examining the transcriptional response of a hemipteran insect to the attack of a biological control agent (Hymenopterous parasitoid), using a new genomic approach developed for this insect pest. The defense response in B. tabaci seems to resemble that of model organisms such as Drosophila melanogaster. Moreover, endosymbionts of B. tabaci seem to play a role in the response to parasitization, and this is supported by previously published results from aphids. Keywords: time course
2008-05-13 | GSE11410 | GEO
Project description:Multinucleated giant hemocytes (MGHs) represent a novel type of blood cell in insects that participate in a highly efficient immune response against parasitoid wasps involving isolation and killing of the parasite. Previously we showed that circulating MGHs have high motility and interaction with the parasitoid rapidly triggers encapsulation, structural and molecular mechanisms behind these processes remained elusive. Here, we use detailed ultrastructural analysis of MGHs and also live cell imaging to study encapsulation in Drosophila ananassae after parasitoid wasp infection. We found dynamic structural changes, mainly driven by the formation of diverse vesicular systems and a large variety of newly developed intracytoplasmic membrane organizations, moreover abundant generation of giant cell exosomes (GCE) in the MGHs. Moreover, we used RNA sequencing to study the transcriptomic profile of MGHs and the activated plasmatocytes 72 hours after infection, as well as the uninduced blood cells. This reveals that differentiation of MGHs is accompanied by broad changes in gene expression. Consistent with the observed structural changes, transcripts mainly related to vesicular function, cytoskeletal organization and adhesion were enriched in MGHs. In addition, transmembrane receptors were upregulated, which may be important for parasitoid recognition. Our results reveal coordinated molecular and structural changes in the course of MGH differentiation and parasitoid encapsulation, providing a mechanistic model for a powerful innate immune response.
2021-12-17 | GSE180960 | GEO
Project description:The cytoplasmic functions of Wiskott-Aldrich Syndrome family (WASP) proteins are well known and include roles in cytoskeleton reorganization and membrane-cytoskeletal interactions important for membrane/vesicle trafficking, morphogenesis, immune response and signal transduction. Mis-regulation of these proteins is associated with immune deficiency and metastasis. Cytoplasmic WASP proteins act as effectors of Rho family GTPases and polymerize branched actin through the Arp2/3 complex. However, recent evidence has revealed that this classically cytoplasmic protein family also functions in the nucleus. Previously, we identified Drosophila washout (wash) as a new member of the WASP family with essential cytoplasmic roles in early development. Here we show that Wash is also present in the nucleus and plays a key role in nuclear organization via its interaction with Lamin Dm0 at the nuclear envelope. Wash and Lamin Dm0 occupy similar genomic regions that overlap with transcriptionally silent chromatin including constitutive heterochromatin. Strikingly, wash mutant and knockdown nuclei exhibit the same abnormal wrinkled morphology observed in diverse laminopathies, including the Hutchinson-Gilford progeria syndrome, and consistent with disruption of the nuclear organization of several sub-nuclear structures including cajal bodies and the chromocenter in salivary glands. We also found that Wash and Lamin knockdown disrupt chromatin accessibility of repressive compartments in agreement with an observed global redistribution of repressive histone modifications. Functional genetic approaches show wash mutants exhibit similar phenotypes to lamin Dm0 mutants, suggesting they participate in similar regulatory networks. Our results reveal a novel role for Wash in modulating nuclear organization via its interaction with the nuclear envelope protein Lamin Dm0. These findings highlight the functional complexity of WASP family proteins and provide new venues to understand their molecular roles in cell biology and disease. We evaluated the effect of Wash knockdown in S2R+ cells on chromatin accessibility using an M.SssI-based approach.
2015-03-10 | GSE59852 | GEO