Ugly Critters Make Beautiful Cell Lines

Blog entry

I know there are a lot of you Xenopus folks out there, so here’s your shout-out. You’ve withstood the test of time and the advent of new model systems competing for your affection and you stayed true to the frog. You shall be rewarded for it! Kinda. If my saying”this stuff is cool!” can be construed as an award then you, my friends, have just won it. But I do not share that love for the frog that gave you the cells. Blech. Anyways, here goes….

Xenopus laevis, the African clawed frog. Ugly. These fat, mottled gray-ish green beasts have beady little eyes and are essentially shaped like an avocado with feet. Clawed feet. On a frog! Truly an ugly beast, to say the least. While I would not pass up a chance to link them to an ugly-ducking scenario with a happy ending, I won’t. They’re homely looking tadpoles that morph into homely looking sad frogs. Some are even albinos you can find in the local pet shop. I find them sickly-looking on top of ugly.

However, us scientists do not preoccupy ourselves with amorous intentions toward the socially accepted definition of beautiful. Well, we do, but we’re supposed to shun that sort of stuff. Maybe because most of us do not occupy that ‘beautiful’ space (I can see the emails coming already!). Anyway, I digress…

Xenopus cells are still pretty useful in the lab, even after the advent of mouse, rat, even dog, as well as other furry lovable creature-derived cell lines threatened the homely frog’s utility in research areas. They have a great way of growing well, much like fish cells (remember that blog?) and rely on relatively simple media formulations (They have the DMEM, FBS, yummy supplements like glutamine, and pen-strep, with HEPES and a few other ingredients). In particular Xenopeus spinal neurons are easily manipulated and seem to do well even after enduring the amount of poking and prodding that would wipe out mammalian neurons. These frogs develop fast, which usually translate into good things happening in the cell culture dish. Anyone who’s ever made the switch from mouse (gestation time, 21 days) cells to human (gestation time, 270) cells knows that fast developers make fast growing cultures. Here’s a paper that did some work with Xenopus spinal neurons:
http://www.ncbi.nlm.nih.gov/pubmed/12884690

But it doesn’t end there. The University of Rochester Medical Center, a very highly regarded institution, uses Xenopus for a number of immunological studies.
http://www.urmc.rochester.edu/mbi/resources/Xenopus/#comparative_model

Essentially, wherever you see Xenopus cultures, you see the same (valid and important, by the way) reasons people use them. They are known to breed easily in captivity, they’re easy to keep alive, and happy (they’re breading so that should make them happy, right?), their cells grow well in pretty easily generated lab conditions, and they have a lot of the same genes as we do when it comes to activating things like development, and growth, and immunology.

So, next time you see one of those homely amphibians, think about how they may have contributed to your health. I know I have to. Otherwise, I’d be writing about how we should eradicate them. Well not really, but man are they ugly!