Monthly Archives: June 2018

Four Diatom Problems

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(By Michael Zheng, 2015)

TEM (Transmission Electron Microscopy) is a rare skill. I did a little when I wrote:
  • Bender, R., Bellman, S.H. and Gordon, R. (1970) ART and the ribosome: a preliminary report on the three-dimensional structure of individual ribosomes determined by an Algebraic Reconstruction Technique. J. Theor. Biol. 29, 483-488.

and learned to appreciate those who do it well.

There are 4 diatom problems I’d like to see solved, for which TEM may prove critical:
  1. What is the pathway (literally, not just biochemically) by which oil droplets are formed, coalesced, accumulated, passed out of the plastids, occupy huge volumes inside the diatom, and via milking or spontaneously get outside the diatom? Such knowledge may prove critical to biofuel production.
  2. Triangular Archaea and triangular centric diatoms sometimes have square (90deg) corners instead of the “expected” 60deg. This suggests some structure, something like a centriole, in those corners. What is there, if anything?
  3. Is there any correlation between the 3D array of microtubules and microfilaments and the shape of a diatom valve? If yes, can we observe how the relationship changes during valve morphogenesis?
  4. In motile pennate diatoms, what is the pathway by which raphe fibrils are formed and exit the cell membrane? Once out, are they attached to the membrane or not, while they traverse the raphe?
Regarding #2: While most plants do not have centrosomes, diatoms do, if not proper centrioles:

Nuns work to save axolotls from extinction.

Gill, V. (2018).

Meet the nuns helping save a sacred species from extinction.

which is a ray of hope for preservation from extinction for our favorite model animal, the axolotl (Ambystoma mexicanum, a neotenic salamander).

When I “retired” in 2011, Natalie and I delivered our axolotl colony to the dinosaur museum in Drumheller, Alberta. See:

Alberta, Canada ~ Royal Tyrrell Museum of Palaeontology

Our book Embryogenesis Explained is based on our axolotl research. Susan Crawford-Young is carrying this on, and soon hopes to be imaging axolotl embryos in 4D at the Canadian Light Source (a synchrotron in Saskatoon, SK, Canada).