RRC ID 47656
著者 Schmid MR, Anderl I, Vo HT, Valanne S, Yang H, Kronhamn J, Rämet M, Rusten TE, Hultmark D.
タイトル Genetic Screen in Drosophila Larvae Links ird1 Function to Toll Signaling in the Fat Body and Hemocyte Motility.
ジャーナル PLoS One
Abstract To understand how Toll signaling controls the activation of a cellular immune response in Drosophila blood cells (hemocytes), we carried out a genetic modifier screen, looking for deletions that suppress or enhance the mobilization of sessile hemocytes by the gain-of-function mutation Toll10b (Tl10b). Here we describe the results from chromosome arm 3R, where five regions strongly suppressed this phenotype. We identified the specific genes immune response deficient 1 (ird1), headcase (hdc) and possibly Rab23 as suppressors, and we studied the role of ird1 in more detail. An ird1 null mutant and a mutant that truncates the N-terminal kinase domain of the encoded Ird1 protein affected the Tl10b phenotype, unlike mutations that affect the C-terminal part of the protein. The ird1 null mutant suppressed mobilization of sessile hemocytes, but enhanced other Tl10b hemocyte phenotypes, like the formation of melanotic nodules and the increased number of circulating hemocytes. ird1 mutants also had blood cell phenotypes on their own. They lacked crystal cells and showed aberrant formation of lamellocytes. ird1 mutant plasmatocytes had a reduced ability to spread on an artificial substrate by forming protrusions, which may explain why they did not go into circulation in response to Toll signaling. The effect of the ird1 mutation depended mainly on ird1 expression in hemocytes, but ird1-dependent effects in other tissues may contribute. Specifically, the Toll receptor was translocated from the cell membrane to intracellular vesicles in the fat body of the ird1 mutant, and Toll signaling was activated in that tissue, partially explaining the Tl10b-like phenotype. As ird1 is otherwise known to control vesicular transport, we conclude that the vesicular transport system may be of particular importance during an immune response.
巻・号 11(7)
ページ e0159473
公開日 2016-7-28
DOI 10.1371/journal.pone.0159473
PII PONE-D-16-16569
PMID 27467079
PMC PMC4965076
MeSH Animals Drosophila / genetics* Drosophila / growth & development Drosophila Proteins / genetics Drosophila Proteins / metabolism Fat Body / metabolism* Hemocytes / cytology Hemocytes / metabolism* Larva / metabolism* Mutation Phenotype Signal Transduction*
IF 2.74
引用数 5
WOS 分野 CELL BIOLOGY
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