Figure 4.

Different stages of membrane invaginations in C. burnetii cells

(A–C) Top panels: Slices through electron cryotomograms of C. burnetii cells (grown in ACCM-2 for 15 days) illustrating different stages of inner membrane invaginations (orange arrows) with 3D segmentations of these stages shown in the lower panels. An early stage of IM invagination is shown in panel A where a protein-like density can be seen at one side of this invagination (red density in the segmentation). Panel B shows a long and curved IM invagination where a protein-like density can be seen between this invagination and the IM (red density in the segmentation, green arrow in inset). A whole multilayered vesicular structure can be seen in panel C. Note that it was difficult to trace the different layers in the tomogram hence it is shown as one large blob in the segmentation in the lower panel (See supplemental informationVideo S2). Scale bar is 100 nm.