Applications of Evolution 3 - tradeoffs in resistance.

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Someone just emailed me a copy of an interesting press release. Some time back, a particular mutation known as CCR5delta32 was identified as conferring greatly increased resistance to HIV in individuals who had two copies of that particular gene (in geek terms, those are individuals homozygous for that particular allele). According to the press release, a group of researchers have discovered that this resistance to HIV comes with a price. The individuals who are homozygous for the CCR5delta32 allele do have greatly increased resistance to HIV, but they also have greatly decreased resistance to the West Nile Virus.

This is interesting (to me, anyway) for a number of different reasons.

Read More (at The Questionable Authority):

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I'm still working on finishing up 3 manuscripts (one book, 2 journal articles) so I've not blogged quite as much this week as I generally do. Next week I should be back up to speed, and have a few topics... Read More

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Another odd tidbit for ya’ll. A genetic search for CCR5delta32 ended up in Europe. It appears to give certain fitness advantage against Y.pestis. They found that the areas that were hit the hardest in the middle ages by the black death were the areas that had the highest number of people with the CCR5d32 mutation. Cool post, I have been working in HIV research for years and this is cool to hear about.

I hope all visitors to this site read this posting. It often seems as if anything “scientific” gets ignored.

This particular one is very light on technical details, yet raises some incredibly important points about how evolution works.

I have to admit that some of the insights had a “Well, Duh!” quality when I first read them (ie that a phenotype which enjoys a reproductive advantage in one environment may be selected against in another environment*). But that’s just because I’ve had a tendency to think about these things.

*Remember, it’s the expressed phenotype, not the underlying genotype, that the viruses interact with directly.

For me, personally, it also raises some philosophical, or dare I say, spiritual points about the relationship of humans with the rest of life and the universe at large.

I think the lack of comments is not the result of lack of attention.

I for one read the link, found it very interesting and educational, but being a layman I simply have nothing to add. Simply saying “Good stuff” seems a bit weak. It is not as if there is an easy target.

Ditto PZ Myers’ crocodile thread.

Some people have left comments at The Questionable Authority (myself included). I agree with Eugene: saying “good stuff” is weak, but I do appreciate the scientific posts: this is all stuff from areas I don’t work in, so it’s always intereting, and a damn sight easier than reading the original papers.

I do have one layman-type question: what does CCR5delta32 do in its spare time, when not starring in PT posts?

Bob

CCR5 is a membrane protein on the surface of T cells - cells involved in the immune system. HIV uses the normal (= more common) variety to enter the T cell without triggering a response.

For more details, ask a microbiologist or immunologist, not an anatomist. ;^)

fusilier James 2:24

Not only is this “Good Stuff”, BUT becasue it is actual science, it is now “Troll Free”! Two, Two good things with only one post!

WTG!

Is it possible that different aspects CCR5 determine the HIV resistance versus West Nile resistance (e.g. two different folds) and that we’ll be able to somehow disentangle the two sides of this coin.

It’d be really lovely to have our cake (HIV resistance) and eat it too (not suffer from increased risk of the West Nile)!

What sort of experimentation might be required to determine whether it is possible to disentangle the two sides?

What sort of work could be done to develop drugs to help with HIV from this discover?

Another odd tidbit for ya’ll. A genetic search for CCR5delta32 ended up in Europe. It appears to give certain fitness advantage against Y.pestis. They found that the areas that were hit the hardest in the middle ages by the black death were the areas that had the highest number of people with the CCR5d32 mutation.

Wellllll.…maybe. Some more info on CCR5 and plague here and here.

CCR5 is a deletion of a receptor that is normally involved in detecting molecules the immune system uses called Chemokines. It’s typically displayed on macrophages and dendritic cells and some T-cells. It basically allows cells of the immune system to follow a chemical gradient around and find their way to sites of interest around your body. When CCR5 is missing, it is not terribly detrimental because there are numerous other chemokine receptors that can maintain enough function so the loss isn’t significant.

what is the good stuff that is on the black death?

This is cool, you have to try it. I guessed 36405, and this game guessed it! See it here - http://www.funbrain.com/guess/

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This page contains a single entry by Mike Dunford published on January 11, 2006 6:29 PM.

Blackstone on Trial was the previous entry in this blog.

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