pharyngeal ultrastructure (EM stack)?

greetings -

I’ve managed to unearth the 1975 paper by Albertson and Thomson that describes the organization and ultrastructure of the C elegans pharynx, based on EM serial sections. They describe their reconstruction method as being based on tracing structures through adjacent sections - I was wondering if anyone had taken their micrographs and assembled them digitally and put them up somewhere, perhaps in a format where one could do some rotations and “see” into the interior in some fashion. I am interested in the morphology and distribution of mitochondria within the pharynx , and have been unable to come up with much information on the subject.

any information on this matter will be greatly appreciated


I don’t have any advice for navigating through the collection or what tools are available, but a lot of EM images have been scanned at high resolution, annotated, and made available at Wormimage, curated by David Hall.

The Albertson and Thomson paper is available in HTML format from the front page of WormAtlas (just scroll down to the “Classic Papers” section and you’ll find it.

As mentioned by Hillel, many of the best TEM images upon which that paper was based are available online at WormImage (, including their original hand-marked color annotations (lists of the color codes are available on WormImage). See especially the animals JSA, N2W, N2T, nd N2U, which offer the largest number of pharynx cross-sections from that work. Those should be comprehensive enough to let you see the layout of mitochondria for various domains, in every cell type.

Unfortunately, no single animal was photographed to completion across the whole pharynx, so the goal of providing a 3D reconstruction through the whole volume will require some stitching between datasets. The project you request may be possible, starting from the images we currently offer online? Certainly could be visually compelling if done right.

One more caveat. At the darkroom stage, many of the archival datasets were adjusted to maximize the use of the print paper, so as the pharynx shrank along its length (like at the isthmus, or at the edge of the bulbs), the image was often enlarged gradually to fill the available space on the page. Thus the exact magnification on final prints tended to drift up & down. This simplified seeing cell features in nice detail on each image, but will mess up a 3D reconstruction unless you remember to take this into account.

The original TEM negatives from the MRC work are also in our collection too, but scanning all of them would be very labor intensive. They have more consistent magnifications than the print sets, and they are still in excellent condition.

Dave Hall