3rd Chromosome Deciphered

veeoh writes: "Another chapter in the human book of life has been published. Scientists working as part of the Human Genome Project(including some from the Wellcome Trust) have deciphered the complete genetic instructions of a third chromosome, one of the 24 bundles of DNA that carry our genetic material. The BBC has an article about the discovery"

Comments

Re:24?

[Byteme]

Then there is Down, Turner's and Klinefelter's syndromes. Down has an extra 21. Turner's is a monosomy X with sexually underdeveloped females. Klinefelter's syndrome are males with extra X chromos, XXY - XXXY. There is also XXX, XXXX and XXXXX female karyotypes with mild effects as the extra X's are inactivated and converted into Barr bodies.

Re:Comparison to mice chromosomes?

[barawn]

No problem. Actually, the main difficulty understanding genetics is to get over the problem in my previous post - DNA is not like computer instructions - all DNA does is code for protein, and then the protein interacts in the body and 'does what it is supposed to do' (hopefully). The belief that genetic engineering can end all disease, make perfect humans, etc. is a common mistake, and definitely not true - many human diseases are completely agenetic (take cancer, for instance - everyone would probably eventually develop cancer, given enough time) and more importantly, many of the mechanisms in place in living systems are simply to fix or deal with things that break (again, cancer). To make humans immune to cancer, for instance, you'd have to make a better system than nature designed - good luck. You could, however, cure it, and that's the real benefit of genetic engineering, is that it may help us cure and treat diseases better.

The other point is that I do want to stress that the mouse/human comparison is not quite as useless as a first glance might make it seem. The fact is, if we know how a protein (and therefore a gene) behaves in a mouse, and we alter that gene, and see how that protein behaves, we've got a good guess that it will cause the same behavior in humans. It's not -guaranteed-, but it's better than doing the experiment blindly on humans (animal rights activists aside: from a purely practical standpoint, mice breed faster than humans and have a shorter lifespan, so from a completely amoral standpoint, it's better to do it on mice. It's also harder to control the environment). Wow I could still get flamed for that comment.

Re:Comparison to mice chromosomes?

[Otter]

I wonder how similar 3rd chromosome of mice is to the 3rd chromosome of the human genome. Any research being done in this field?

Imagine if you took the 23 human chromosomes, broke them up into a couple of hundred chunks (I forget the exact number) and randomly reassembled them to make the 20 mouse chromosomes. That's what it looks like. So rodent and human chromosomes don't directly map to one another (that site aside) but there are large chunks containing many genes that can be directly compared.

With the mouse genome being sequenced now, that's one of the big things going on -- regions that are similar between the mouse and human sequences are presumably imnportant enough to be conserved over hundreds of millions of years, and therefore give a clue to the location of important features like genes and regulatory elements. That's one of the major pushes in genomics right now.