Regeneration

Inspired by some of my friends who have started blogging about their science, I will attempt a few posts to spread awareness(!!!) about cell biology and perhaps a little about developmental biology. Here goes nothing.



Ugh! Now that's a face that only a mother could love. Maybe..not only mothers but also the few scientists who have chosen it as their model organism. It is not a rule that the model organism you work on should be cute but it helps.(first said by Ralph Greenspan). Imagine waking up every morning and thinking "I have to go back to the lab to work on Axolotl" and then that horrendous image would come to mind. I for one would definitely just turn back and go to sleep again.

However this awful creature is making waves though for one thing that it does - regeneration. If you cut off a limb of this amazing animal it can regerate it....completely! Magic!

Not really. Of course it would have a 'developmental program'[a series of events involving the sequential expression and use of proteins for a develpomental event like formation of a wing etc] . Just that the specific developmental program is not known yet. Once that puzzle is cracked it would bring in billions to the person who figures out how this is done. (and you thought there was no money in science!)

The brightest among you would have figured it out why this thing is uber-hot by now. The application of this program either in vitro or in vivo could possibly lead to regeneration of human body parts like a factory.

All paradise and glory but there is catch! (isn't there always?)

Unlike my favourite model organism, (the fruit fly - muuuaaah!) the genetics of axolotl has not yet been well worked out. I am sure it is because of its hideous looks but then no one asked me. It is related to lizards and genetics here is difficult. For good genetics you need a way to make 'bad genes'(mutations for the purists) so that you can study the effects of these 'bad genes'. One way is to hang around and wait till you get a 'bad gene'/mutation that arises spontaneously in the population. The other way is to actually just go in and damage the damn DNA.

Recently scientists have managed to do something like that. They were able to make transgenic Axolotl i.e. they have managed to put some foreign DNA into a wild axolotl. Actually they put GFP into it.

Why GFP? GFP stands for Green Flourescent Protein which is actually a gene from Jellyfish that glows under Ultra-Violet light. The beauty of GFP is that it can be expressed in any organism still it would glow under UV. Therefore, this is a wonderful non-invasive marker for cells that you want to track.

Advantage Axolotl...and now you can track the cell lines with GFP as they develop so that you will be able to follow which cell gives rise to what(the so called cell lineage). So then you can determine in the final regerated limb which cell came from where. Of course this technique can be used to damage DNA to make mutants as well. With this new technique we should be able to figure out soon how axolotl manages to regenerate body parts.

So will be able to order our body parts soon? Don't hold your breath. There is still a long way to go.

P.S. For the nitpickers, axolotl is not the only organism that can 'regenerate', there are also the planaria(lower in the evolutionary ladder and therefore farther from humans), lizards(tails!) and earthworms. In addition, there was one report of a mouse that can completely heal its heart.

(The picture is from here.)