Chimaeras

[oldhen]

The Guardian reports that researchers have created a transgenic mouse that carries an entire human chromosome - chromosome 21 {Original article in Science magazine here - subscription required though}. Trisomy, or three copies, of chromosome 21 causes Down's Syndrome. As a model to study Down's Syndrome, this mouse model is going to be invaluable,

Comments

[latelyontime]

I find chimeras fascinating actually. The whole idea that the biology that we take as predefined is also as fluid as the other abstractions like consciousness or perception is intriguing.
It is perhaps also a reminder of the fact that we too are evolving. If human beings are the highest strain in the chain of evolution, is it possible that like H.G. Wells' predictions, we will now start devolving or something?

[oldhen]

The whole idea that the biology that we take as predefined is also as fluid

That is very true.. It's also very humbling in some sense.. I'm just concerned that there's no policy in place to demarcate an animal with rights, from one without.. That line is somewhat fuzzy, and I think that the concept needs to considered seriously..

reminder of the fact that we too are evolving.

I'm sure we are, but into what heaven knows.. The selection pressures are different modern medicine has removed the old selection pressures of physical fitness to a large extent, who knows what the new pressures for mate choices are.. Maybe tomorrow women will start finding reading Umberto Eco and Salman Rushdie incredibly sexy :) (might as go the whole hog while building castles)

[latelyontime]

I was also approaching it from a feminist perspective. For a long time feminists around the world have fought against the predetermination that biology brings with it. The whole sex-gender divide and the battling of the sexes is predicated on the notion that biology is what we are born with. One of the first feminist theorists to break out of that grid was Donna Haraway when she started looking upon cyborgs as the new frontier to realise our human selves. I think thats why chimaeras are so intriguing.
As for the ethical call on what constitutes human or not...that is an entirely different ball game.

p.s. Women already find reading umberto eco and salman rushdi incredibly sexy :)

[oldhen]

battling of the sexes is predicated on the notion that biology is what we are born with

Interesting - hadn't really thought of it quite like that.. I see where you're coming from though, have had many a debate about what you're biologically "born with" and what is "natural" and "un-natural" etc...

Women already find reading umberto eco and salman rushdi incredibly sexy

I knew I was hanging out with the wrong crowd.. :)

[shortiyergirl]

I agree.....

This definitely advances science in terms of giving us a mouse model but also sets precedent for other such chimeras in the future and soon we may be in the business of creating monsters or weird creatures....and what then? I don't know how you can get a bunch of scientists together though to agree on a common policy of ethics.

Btw, check out the forbes article listed on my blog (latest entry). I think you'll enjoy it.

[oldhen]

Btw, check out the forbes article listed on my blog

Yes, thanks for the tip - that was interesting.. Although I can't say I really have any expertise in intellectual property or patenting, so can't really comment on it - the most profitable (by far) university patent to date though is Gatorade :)

[metafizzics]

chimeras have been use for a fairly long time... i don't mean that whole human chromosomes have been inserted into other organisms, but you could say transgenic mice or knockout mice are chimeras in a way.
how much human dna does a mouse have to have within it for it to be called a chimera?

[oldhen]

you could say transgenic mice or knockout mice are chimeras in a way.

True, single-gene trangenics have been around for a long time, and hey I'm a geneticist myself, so I can't in good conscience have hassles with that.. Technically and conceptually however, this work is a big leap forward.

A mouse carrying a human gene has one gene out of 25,000 odd that is human, make a mouse carrying a whole chromosome, and you're more in the ballpark of 1 in 23 now - that's a huge leap. Technically as well this a tour-de-force, as the kinetochore is foreign and yet they're able to get the chromosome to segregate.. I'm far from advocating a blanket-ban on transgenic technologies or any such thing.. I'm just concerned that the line at which an animal gets rights is very fuzzy and needs to be clarified - soon.. In all the misplaced brouhaha over cloning, there are many other ethical issues that are not being given seriously consideration..