FIG 6.

Model of formation of the two types of vesicle chains by pearling. (A) Formation of an extension of the outer membrane, which elongates as a tube-like structure and then transforms into a vesicle chain by pearling. (B) Formation of an inner membrane vesicle which remains enclosed by the outer membrane and gets transported away from the cell due to the elongation of the outer membrane tube. This explains the different types of vesicles (O-IMVs and OMVs) in one vesicle chain and also the phenomenon that the end of the vesicle chain has a larger vesicle (Fig. S1A, D, and G).