Drosha-independent DGCR8/Pasha pathway regulates neuronal morphogenesis

Significance Understanding the neuronal functions of diverse RNA pathways will lead to treatments of human neurological diseases that are caused by perturbations in RNA metabolism. Two proteins, Drosha and Pasha/DGCR8, play important roles in neurons, where they are responsible for the biogenesis of many microRNAs. Here, we show that Pasha/DGCR8 also promotes the morphogenesis of neurons in developing fruit flies independently of Drosha and therefore of most microRNA production. These studies therefore illuminate a novel function of Pasha that is medically relevant, because loss of the human ortholog of Pasha may contribute to cognitive and behavioral disorders associated with DiGeorge syndrome.