A press release from the European Molecular Biology Laboratory (EMBL) uses the above image to illustrate what happens when a particular protein is absent from the molecular mix in a cell: microtubules come unseam’d. A protein called “Mal3p” binds two sides of a protein sheet curled into a tube, so without it, you see the unzippered effect above. A succinct visual punch line to the press release.
Methinks the caption is not written by a native speaker of English, however: “In the absence on Mal3p microtubules are unstable and can open at the seam. The image shows a microtubule with opening seam [bottom left], seen through the electron microscope.” Aside from “on” instead of “of,” it sounds like there’s only one electron microscope making images out there.