Essential Role of Duox in Stabilization of Drosophila Wing

Abstract

NADPH oxidase produces reactive oxygen species (ROS).Drosophila melanogaster has two homologs of NADPH oxidase, dNox and dDuox, with functions that remain unclear in vivo. To clarify these functions, two independent transgenic fly lines expressing dsRNA targeted for different portions of dDuox mRNA were used. In both flies, en-GAL4> UAS-dDuoxIR 976 -1145 and en-GAL4> UAS-dDuoxIR 370 -518 , in which dDuox was knocked down selectively in the posterior area of the wing disc, the posterior compartment of the adult wings became paler and more fragile with wing veins that were indistinct by comparison with the anterior one. Fluorescence staining of the en-GAL4> UASdDuoxIR 976 -1145 adult wings revealed that the ROS concentration in the posterior compartment was significantly lower than that in the anterior compartment. Moreover, in these flies, the posterior compartment of the wing imaginal disc showed a greater number of apoptotic cells detected by immunostaining with anti-cleaved caspase-3 antibody than those in the anterior compartment. Respective knockdown of tyrosine hydroxylase or dopa-decarboxylase showed paler wing blades in the posterior compartment similar to the phenotype of dDuox-knockdown files. Along with this observation, analysis of the catecholic and dityrosine components in the wings of adult flies proved that dDuox plays important roles in the stabilization of the cuticle structure of the wings via tyrosine cross-linking, the sclerotization and melanization processes possibly through ROS production. These dDuox-knockdown fly lines would be useful tools for further studying dDuox functions during the development of Drosophila.

The dual oxidase gene BdDuox regulates the intestinal bacterial community homeostasis of Bactrocera dorsalis

“…Beyond the antimicrobial function of the BdDuox gene, it may have other functions in the development of B. dorsalis, because of its expression levels at different development stages and tissues of adult. In this line, dDuox has been described for playing important roles in the stabilization of the cuticle structure of the wings in Drosophila (Anh et al, 2011), and mutation in Duox is lethal (B Lemaitre, personal communication). Duox has been extensively studied for its role in the antibacterial defense against infectious bacteria; our study highlights the importance of BdDuox in the control of intestinal bacterial community homeostasis in the intestine.…”

“…It is thought that stem cell proliferation is induced upon epithelia damage caused by ROS. In addition, Duox plays important roles in the stabilization of the cuticle structure of Drosophila wings (Anh et al, 2011), and Duox together with peroxidase contributes to the peritrophic matrix of the Anopheles gambiae midgut, affecting gut permeability to immune elicitors (Kumar et al, 2010).…”

Immunity in Drosophila melanogaster — from microbial recognition to whole-organism physiology

“…ROS are induced by two conserved NADPH enzymes; dual oxidase (Duox) generates microbicidal hydrogen peroxide (H 2 O 2 ) and hypochlorous acid 82–84 , whereas NADPH oxidase (Nox) generates H 2 O 2 . In addition to its microbicidal activity, ROS have instructive roles in tissue repair, wound healing and haematopoiesis in both flies and mammals, during which they act as a second messengers or signalling modulators 85–87 . How particular bacteria are sensed to induce these responses is unclear.…”

Ovarian Dual Oxidase (Duox) Activity Is Essential for Insect Eggshell Hardening and Waterproofing

“…In A. gambiae, Duox appears to cross-link peritrophic layer proteins by forming dityrosine bonds on the luminal surface of midgut epithelial cells, a process that limits the diffusion and activity of immune elicitors derived from microbiota (13). In D. melanogaster, Duox plays an essential role in the stabilization of the wing cuticle structure by producing the H 2 O 2 required during sclerotization, melanization, and tyrosine cross-linking (32). Several studies performed with D. melanogaster and A. aegypti (2,5,6,33,34) have demonstrated the importance of chorion protein cross-linking through the oxidation of tyrosine residues and formation of dityrosine bonds during insolubilization of the eggshell protein moiety.…”

“…In D. melanogaster and A. aegypti, Duox has an immunological role in producing H 2 O 2 that controls the levels of intestinal microbiota (32,33). In A. gambiae, Duox appears to cross-link peritrophic layer proteins by forming dityrosine bonds on the luminal surface of midgut epithelial cells, a process that limits the diffusion and activity of immune elicitors derived from microbiota (13).…”