Fig. 6

Post-mitotic neurons lack paraspeckles in vitro, but their assembly can be triggered by dsRNA. a Paraspeckles are present in glial cells but not in neurons in murine primary hippocampal cultures. Cultures were analysed at DIV14 by NEAT1_2 RNA-FISH. A representative image is shown. Neuronal nuclei are circled and paraspeckles in glial cells are indicated by arrowheads. b Paraspeckles are present in human neural precursor cells (NPCs) but disappear during their differentiation into motor neurons. Cultures were analysed at the indicated time-points by NEAT1_2 RNA-FISH. c and d Treatment of Day 40 cultures of human motor neurons with poly(I:C) leads to activation of IFN signaling, increased NEAT1 expression (c) and paraspeckle assembly in a fraction of cells (d, arrowheads). In c, gene expression was analysed by qRT-PCR (n = 4). *p < 0.05, **p < 0.01 (Mann-Whitney U-test). Scale bars, 10 μm in a, b and 20 μm in d