The authors’ conclusions are generally well supported and the electron microscopy provides some of the clearest images to date of the junctional pores.
About 20 years ago it was shown that in order to preserve crucial ultrastructural features of cyanobacterial cell walls, the cells have to be processed using cryo-procedures (Envelope structure of four gliding filamentous cyanobacteria. J. Bacteriol. 1995, 177, 2387–2395). The authors use an outdated and very artifact-laden method to process their samples. This choice is responsible for a number of shortcomings that need to be addressed: The lack of certain features such as the S-layer and the oscillin fibrils in the reported pictures are attributable to the choice of preparation, as they are clearly present in two species of the same genus described in the above cited paper. Moreover, these structures would explain the rotation of the cells that now is somewhat “mysteriously” explained by a helical slime ejection that is not supported by the observed arrangement of the nozzles. Therefore the authors should do the following: Response: