The Rockefeller University Press

“Come back to us when you have demonstrated this in humans,” said an editor to one of my postdocs presenting a poster at a recent conference. We use the protozoan parasite Trypanosoma brucei as a model to study Golgi duplication, and the implica-tion was that the results of such studies are only worthy of a wider audience once they have been demonstrated in humans, or at least one of the other crown eukaryotes, that is, yeast, flies, worms, fish, or mice. It was not always so. One only has to leaf through the early cell biological literature, from the fifties onwards, to appreciate the breadth of organisms under study. This is par-ticularly true of The Journal of Cell Biology (or The Journal of Biophysical and Biochemical Cytology, as it was titled back then). The range was vast: from crickets to crabs, guinea pigs to grasshoppers, limpets to locusts, peas to pigeons, spiders to snails, and termites to turtles. One reason for this, of course, was the invention of the electron microscope and its application to the biological sciences. Almost any cell or tissue could be fixed, embedded in plastic, and sectioned, and then viewed at a resolution far exceeding that of light microscopy, revealing subcellular architecture that had never before been seen. Such studies not only attested to the validity of the cell theory, the basis of all known life on earth, but also showed that many cells were highly specialized, committing a large part of their metabolic energy to a particular cell function. Such studies identified model systems that could be used to pick apart a cell function into its component parts. In my own field, membrane trafficking, the premier ex-ample was the pancreatic acinar cell from guinea pigs (Fig. 1), which is responsible for secreting (in a regulated fashion) those Correspondence to Graham Warren