The Bacterial Symbiont Wolbachia Induces Resistance to RNA Viral Infections in Drosophila melanogaster
(A) Extracts of flies 6 d after injection with 500 TCID50 DCV were probed in a Western blot with anti-DCV. Anti-tubulin was used as a loading control. Flies used were: w1118 iso ; w1118 iso raised with VF-0058–3; VF-0058–3; and progeny of VF-0058–3 raised with w1118 iso.
(B and C) Fifty 3–6-d-old males, per sample, were injected with 500 TCID50 DCV, and their survival followed daily. (B) Males and females from resistant (VF-0058–3) and sensitive (VF-0058–3t) stocks were crossed in the four possible combinations, and their progeny were tested for DCV resistance. The assay was repeated with females with similar results. (C) VF-0058–3 embryos were surface sterilized with bleach, raised to adults, and their resistance to DCV compared with non-treated VF-0058–3 and w1118 iso flies. The assay was repeated with females with similar results.
(D) DNA staining, with propidium iodide, of 0–2 h embryos of VF-0058–3, VF-0058–3t, w1118 iso, VF-0097–3, and VF-0097–3t. Extranuclear DNA staining corresponds to bacteria. Scale bar, 10μm.
(E) PCR amplification with wsp and wspB primers on DNA extracts of VF-0058–3t, VF-0058–3, VF-0097–3t, and VF-0097–3 embryos. PCR amplification with mt 12S rRNA primers was done as a DNA extraction control.
(F) PCR amplification with primers specific for Spiroplasma 16S rRNA gene on DNA extracts of RED-67, VF-0058–3, wt 1, wt 2, wt 3, wt 4, wt 5, and wt 6 adults. PCR amplification with mt 12S rRNA primers was done as a DNA extraction control.