Fig 4. Bgs1 and Pxl1 cooperation is essential for the septum synthesis.

(A-D) Transmission electron microscopy images of wild-type cells (A), pxl1Δ (B), Pnmt81-bgs1 ⁺ (C), and pxl1Δ Pnmt81-bgs1 ⁺ (D). Open arrowhead (in section B): Thick growing septum. Arrow (in section D): Projections of cell wall material that is laid down along the cell cortex. Arrowhead (in section D): Old thick septa without primary septum generated during earlier times of bgs1 ⁺ repression. Cells were grown to early log-phase in EMM+S and shifted to EMM+S+T for 40 h, and then processed for electron microscopy as described in the Material and Methods section.