Tardigrade protein helps human DNA withstand radiation (2016) | Hacker News Reader

Tardigrade protein helps human DNA withstand radiation (2016)

nature.com

42 pointsoedmarap10 comments

I wonder what the cost is. If producing a protein that protects against these things was without a downside, it seems likely many species would have selected for it. I feel there must be a downside to it that selects against it in most organisms.

Bare in mind that tardigrades are known for being found everywhere, including extreme environments, and therefore there would be a selective advantage in being resilient to many forms of damage such as heat, cold and radiation. Most species stick to a particular niche and therefore mitigate the need to select for such resistance genes.

I don't see it. Why would it be selected for if Earth is a relatively radiation free environment? Wouldn't the "downside" be that cell energy could be better spent on more relevant issues?

I understood the evolutionary selection was for surviving dessication. It just so happens that evolutionary strategies for water loss also work for radiation.

Given that it’s a foreign protein, I’d expect a potential autoimmune/allergic response in some part of the population.

Check the first comment on that page https://www.nature.com/news/1.20648#comment-2911888136

> I think that the single most significant property of the adult tardigrade in relation to stress resistance is that its somatic cells are eutelic, that is, after hatching as an adult, the somatic cells do not divide

Tardigrades are very peculiar in this regard: after hatching, they grow to adult size not by cellular division (mitosis), but by growing the cells (hypertrophy).

If that's the key to their ability to withstand radiation (beyond the effects of 'Dsup'), we humans have no hope of using the same trick.

(Disclaimer: I have no idea what I'm talking about, and haven't read the paper.)

I thought eutelic organisms experience mitosis until they reach maturity but that's coming from Wikipedia so ymmv.

Well spotted. I think the tardigrade is special even for a eutelic species. From Wikipedia:

> The eggs hatch after no more than 14 days, with the young already possessing their full complement of adult cells. Growth to the adult size therefore occurs by enlargement of the individual cells (hypertrophy), rather than by cell division.

We're finally getting close to discovering the spore drive.

This would make S.T.A.L.K.E.R. a far less interesting game.

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