Fig 6.

Senataxin foci correlate with the formation of transcription-induced RNA/DNA hybrids. (a) HeLa cells were treated for 24 h with or without the transcription inhibitor α-amanitin (50 μM) prior to fixation and immunostaining. (b) HeLa cells, grown on a coverslip, were treated with or without aphidicolin for 24 h and permeabilized for 10 min with Tween 20 at room temperature, followed by incubation with or without RNase H1 for 10 min. Cells were fixed and immunostained for senataxin and cyclin A. The percentage of S/G₂ cells (n = 250) with >5 senataxin foci was quantified for each condition. (c) GFP-tagged RNase H1 was transiently expressed in HeLa cells for 24 h before the cells were fixed and immunostained for senataxin, 53BP1, and GFP antibodies.