Fig. 7

R-loops induced by transcription-replication conflicts determine some meiotic DSBs. (A) Schematic representation of the ARS315-TAH1 head-on collision. ARS315Δ refers to a strain from which the ARS315 sequence has been deleted; TAH1 rev refers to a strain in which the orientation of the TAH1 locus was inverted; ARS306-TAH1 rev refers to a strain constructed by inserting the ARS306 sequence into the TAH1 rev strain background to induce a new head-on collision between ARS309 and TAH1. The red bars indicate the Spo11 ChIP‒qPCR detected regions. (B) Spo11 ChIP‒qPCR of the WT, ARS315Δ, TAH1 rev, and ARS306-TAH1 rev strains at 2 h after sporulation. (C) Schematic representation of the ARS309-ADY2 head-on collision. ARS309Δ indicates the strain deleted ARS309 region, ADY2 rev indicates the strain changed the ADY2 orientation and ARS309-ADY2 rev indicates the strain changed the ARS309-ADY2 orientation. (D) Spo11 ChIP‒qPCR in the WT, ARS309Δ, ADY2 reverse and ARS309-ADY2 reverse strains at 2 h after sporulation. (E) Schematic representation of ARS733-MPC3 head-on collision. ARS733Δ indicates that the strain deleted the ARS733 region, MPC3 rev indicates that the strain changed the MPC3 orientation, and ARS306-MPC3 rev indicates that the MPC3 rev strain inserted the ARS306 sequence to create a new head-on collision. (F) Spo11 ChIP‒qPCR in the WT, ARS733Δ, MPC3 reverse and ARS733-MPC3 reverse strains at 2 h after sporulation. (G) Dual roles of R-loops in meiotic DSB formation and processing