Glial hTDP-43 expression results in early and dramatic de-suppression of the <i>gypsy</i> ERV.

<p>(A) Transcript levels of <i>gypsy ORF2</i> (<i>Pol</i>) as detected by qPCR in whole head tissue of flies expressing hTDP-43 in neurons (<i>ELAV</i> > hTDP-43) versus glia (<i>Repo</i> > hTDP-43) at a young (2–4 Day) or aged (8–10 Day) time point. Transcript levels normalized to <i>Actin</i> and displayed as fold change relative to flies carrying the hTDP-43 transgene with no Gal4 driver (hTDP-43 / +) at 2–4 Days (means + SEM). A two-way ANOVA reveals a significant effect of genotype (p < 0.0001) but no effect of age (p = 0.5414). <i>N</i> = 8 for all groups. (B) An equivalent analysis shows that <i>gypsy ORF3</i> (<i>Env</i>) likewise displays a significant effect of genotype (p < 0.0001) and no effect of age (p = 0.6530). <i>N</i> = 4 for the 2–4 Day cohort and <i>N</i> = 5 for the 8–10 Day cohort. (C) Central projections of whole mount brains immunostained with a monoclonal antibody directed against <i>gypsy</i> ENV protein reveals dramatic, early accumulation of ENV immunoreactive puncta in brains expressing glial hTDP-43 (5–8 Days) in comparison to both age-matched genetic controls (<i>ELAV</i> / +; <i>Repo</i> / +; hTDP-43 / +) and flies expressing neuronal hTDP-43. This effect persists out to 19–25 Days post-eclosion. <i>ELAV</i> / +, 5–8 Day (<i>N</i> = 3), 19–25 Day (<i>N</i> = 4); <i>Repo</i> / +, 5–8 Day (<i>N</i> = 3), 19–25 Day (<i>N</i> = 3); hTDP-43 / +, 5–8 Day (<i>N</i> = 5), 19–25 Day (<i>N</i> = 2); <i>ELAV</i> > hTDP-43, 5–8 Day (<i>N</i> = 2), 19–25 Day (<i>N</i> = 4); <i>Repo</i> > hTDP-43, 5–8 Day (<i>N</i> = 7), 19–25 Day (<i>N</i> = 8).