Charaids

[gendanken]

Knocking them out is a different story. So mice knockouts have absolutely nothing to do with gene therapy in humans.

Really, what I was getting at is their making it sound too easy.
As if the major hurdle is an ethical one, not biology.

Read any journal/book, accessible to the lay, and you'll get this idea.

But what about methyllation? Is that as complicated? In mice, say.

 

[zyncod]

No - as someone intimately acquainted with biology - nothing is ever as easy as they make it sound in the media. Even things that the media trumpet that ARE completely proven have almost a decade of clinical trials to get through before they have any effect medically. But gene therapy for diseases such as SCID does show a great deal of promise - again, the problems are the scientists/doctors coming up against the unreal promises of the media. Retroviral gene therapy carries with it an inherent risk of causing cancer if the inserted gene gets in the middle of another important gene (eg, p53). But, according to the media, gene therapy is a "magic bullet," so any adverse consequences are a serious matter in their eyes. However, any extreme therapies carry with them a serious risk; just the chemotherapy involved in bone marrow transplants has a 3% risk of causing cancer (in order, perversely, to cure cancer).

As far as methylation goes, it's about equally complex in all mammals. It's actually more complex in plants - methylation is a very, very ancient biological tool. Bacteria have restriction enzymes (arguably one of the most important tools in molecular biology) that cut DNA at defined sequences - eg, CCATGG. For a lot of bacteria, their genomes would be protected from cutting by methylation of these (hypothetical) CCATGG sequences. However, CCATGG sequences in bacteriophage (viruses that attack bacteria) genomes would not be methylated. Thereby, the restriction enzymes would selectively destroy viral genomes and not bacterial ones.

 

[invert_nexus]

True - but DNA, not chromatin. That's a different chap entirely.

Yes. It's a different 'chap' but that doesn't mean that it has nothing to do with DNA expression. The human genome has been mapped out and now we are beginning to realize that there is more to DNA than the genome.

For one thing, 'genes' that code for protein are not the whole story. What was once passed off as junk is now known to be, at least in part, critical to cell development and the well-being of the organism as a whole.

The same gene can form different protein depending on factors that I don't pretend to understand. The introns that are cut from the RNA have something to do with it as well as other factors (other RNA's being expressed. Non-coding RNA. Chemical messages within the cell. Who knows?)

The introns are also not all allowed to simple degrade as was once thought. They and other pieces of 'junk' DNA are now thought to serve direct regulatory functions in the cell without needing to code protein.

Also. There are epigenetic factors to consider.

Methylation is one.

And also the chromatin itself. The histone proteins that the DNA wrap around can be tagged with acetyl molecules which act as a volume switch to enhance expression of nearby genes. The process, as far as I know, is poorly understood and there is a whole library of markers that act on gene expression which is almost completely unknown. Research in this area is only just beginning and once it is mapped out we may finally begin to understand.

There is a program to map out all the methylation sites similar to the Human Genome Project. There is so much more to genetic expression than DNA that we are only scratching the surface.

I don't really have the time to go much into this right now (nor am I an expert), but suffice it to say that there is much more to DNA than dogma would have us believe.

I also have to add that your derogatory attitude avails nobody anything. Gendanken has created a thread here asking questions of people who know and you come in with this smart ass attitude trying to raise her ire because you know that she is easily 'irked'.

If you know something about the subject then why not share the knowledge rather than your attitude?

 

[Hercules Rockefeller]

But what about methyllation? Is that as complicated? In mice, say.

If I undertsand you, you've been suggesting using methylation as a therapeutic strategy. Yes?

There is no doubt that methylation results in repression of gene activity but we do not have any sort of fine control over this biological process. We cannot manipulate this process with any precision like we can with many other cellular processes. We have known of the main DNA-methyltransferase enzymes responsible for both “maintenance methylation” and “<I>de novo</I> methylation” for about 6 years. What we don’t know is how the cellular specificity of these enzymes is controlled. For instance, almost 50% of human genes are located close to CpG islands (target areas of methylation), with the methylation status of the CpG island reflecting the expression pattern of the adjacent gene. Housekeeping genes (those that are expressed in all tissues) have unmethylated CpG islands, whereas the CpG islands of tissue-specific genes are unmethylated only in those tissues in which the adjacent gene is needs to be expressed. But how this specificity is controlled is unknown. Methyltransferase knockout mice exhibit global defects in methylation.

Other components of the methylation pathway have been discovered, such as methyl-CpG-binding proteins (MeCPs). It is possible that we will learn how cells can specifically direct the methylation of some genes but not others. But as it stands at the moment, methylation is nowhere close to being developed as a therapeutic strategy, nor will it for some time.<P>

 

[gendanken]

Vert:

And also the chromatin itself. The histone proteins that the DNA wrap around can be tagged with acetyl molecules which act as a volume switch to enhance expression of nearby genes. The process, as far as I know, is poorly understood and there is a whole library of markers that act on gene expression which is almost completely unknown. Research in this area is only just beginning and once it is mapped out we may finally begin to understand.

Murmur...you and your Google.

Good call on QuarkHead, fucking hippie.

Thread's dead, parting shots:

If I undertsand you, you've been suggesting using methylation as a therapeutic strategy. Yes?

Precicely.

And I'm printing out yours and Zyncod's posts.
Speaking of-

No - as someone intimately acquainted with biology - nothing is ever as easy as they make it sound in the media

I'm not getting this from the churlish science section in the Newspaper.

Mike West for example, is a geneticist turned author with good standing in the scientific community- Sagan-esque without the annoying romance.
He's responsible for discovering this almost magical enzyme we call telemorase.

This, and any chance I have to read on regenerative medicine- journals off and online, which becomes a task in itself online as one has to ~subscribe~ first to read the article.
Oooooh.
Ahhhhhhh.

Ridley is probably the only one I'd remotely call 'media'. He's....spurious.
Interesting though.

But thank you dearly for your posts.
I'm printing them both.

 

[invert_nexus]

Gendanken,

Murmur...you and your Google.

Pause.
A smiley???!!
My eyes.
I'm blind!!

Anyway. To repeat an oft-used phrase (one which I suspect may end up being tattooed on my ass someday): "Google, my ass."

That was from one of those Scientific American articles I sent you which you probably never looked at.
You know. The ones on the Unseen Genome and The Hidden Genetic Program? Epigenetics ring a bell?

Damnit, woman. Download the damn acrobat reader and read the bitches.

Good call on QuarkHead, fucking hippie.

Maybe he was just having a bad day or something. He's turned a new cheek in my thread. Come on, QuarkHead. Come out and apologize. You were an asshole in here, you know.

I'm not getting this from the churlish science section in the Newspaper.

You know how these 'scientists' are about 'popular science'.
Kidding.
They have a right to be down on it a bit, but for some of us who don't have access to scientific journals (except by crook) it's all we have.

I suspect that even Mike West probably downplayed many elements of it in order to appeal to a more general audience. Such is the perils of popular science.

 

[gendanken]

That was from one of those Scientific American articles I sent you which you probably never looked at.
You know. The ones on the Unseen Genome and The Hidden Genetic Program? Epigenetics ring a bell?

Which you had to google for- its a general slur used to mock those that never cared for the things they're currently so familiar with.
Beucase of search engines.
Geez man, lighten the fuck up. What I'm saying is true. So?

you probably never looked at

No, which you know I haven't beucase somebody can't send it it in right format.
Here it goes again.......

At any rate, how you can stand to read a computer screen for hours as opposed to paper and still not have glaucoma is beyond me.
Paper rules.

Maybe he was just having a bad day or something. He's turned a new cheek in my thread. Come on, QuarkHead. Come out and apologize. You were an asshole in here, you know.

I'd still stomp his face into ashphalt.

Fucking prick.

I suspect that even Mike West probably downplayed many elements of it in order to appeal to a more general audience. Such is the perils of popular science.

In a sense.
But when people say 'media' I think of those last minute pot shots where the office boy/'reporter', whose never been curious enough to look at the stars let alone written a word on physics or astronomy, is suddenly on CNN lecturing the masses on Hubble or a frozen lake on Mars.

With neat, eye-catching graphics 98% of the content.
That's so kyul! Hey, neat, now that's science!
Right.

Burn them all.

 

[Satyr]

How…..original.

 

[invert_nexus]

Gendanken,

Which you had to google for

Buzz!
Wrong again.
Google had nothing to do with these articles. They're all sitting on my hard drive.
Every Scientific American from 93 to present.
And yes. I'm probably going to go blind...
I've been reading a cellular biology text book lately though. Interesting stuff.

Geez man, lighten the fuck up. What I'm saying is true. So?

I don't mind it when it is true. But when it's not...
(Anyway, you know as well as I that I'm not mad.)

its a general slur used to mock those that never cared for the things they're currently so familiar with.
Beucase of search engines.

A 'general' slur. Directed at an individual isn't general anymore.

No, which you know I haven't beucase somebody can't send it it in right format.

Do you have any idea how long I spent trying to figure out how to convert a pdf to a doc? It can't be done. Not in a legible way.
All you need to do is download Acrobat Reader and problem is solved. You should have it anyway. Too much information is only available in pdf format to not have Reader installed.
I could convert it to PostScript, but the program to read it with is just as big a download as Reader and more crude in function.
*edit* Yeesh. I just happened to look at the postscript file that I made before and just realized that it adds almost a megabyte in size. That's nothing to someone with broadband, but you're on dialup. Hence your reluctance to download reader to begin with.*end edit*

DOWNLOAD READER.

I'd still stomp his face into ashphalt.

Now. Now.

But when people say 'media' I think of those last minute pot shots where the office boy/'reporter', whose never been curious enough to look at the stars let alone written a word on physics or astronomy, is suddenly on CNN lecturing the masses on Hubble or a frozen lake on Mars.

I hear you. But, we are stuck on this side of the scientific divide and practically all our sources are called 'media' by real scientists.

Burn them all.

Heh. Reminds me.
You read this?


'Satyr':

How…..original.

Isn't it?
Isn't there a sun-dappled field somewhere you should be frolicking in?

 

[gendanken]

Buzz!
Wrong again.
Google had nothing to do with these articles. They're all sitting on my hard drive.
Every Scientific American from 93 to present.
And yes. I'm probably going to go blind...
I've been reading a cellular biology text book lately though. Interesting stuff.

You know, and I know, that this never meant much to you.
Until recently.
My platform.

Isn't it?
Isn't there a sun-dappled field somewhere you should be frolicking in?

Or a sandbox to go sifting through for 'tribe members"?

I'll do it again- .

DOWNLOAD READER.

Downloaded.

Thread is beyond dead.

 

[invert_nexus]

You know, and I know, that this never meant much to you.
Until recently.
My platform.

Interesting perspective you have.
So. I never cared for either genetics or cellular biology until recently?
I know no such thing. But apparently you do.
I will admit that it has taken a back seat to other areas of investigation recently, but you make it sound like I knew nothing about the subject nor cared to two weeks ago.

Ok then.
Your platform.

Reminds me of a song.

One foot on the platform. And the other foot on the train. I'm going back to New Orleans. To wear that ball and chain.​

 

[zyncod]

Okay - thread is dead. But - to finalize the 'media' comments, what I said holds true even for popular science books. No-one publishes a book who is not either dead set against an issue (read: psychologists in the 'nature' issue of the nature/nurture debate) or improbably optimistic about a particular issue. The worst form of this is self-published communiques from universities/research centers. My roommate works at Rockefeller University, and their self-published Scientist magazine describes on the front page how Rockefeller is going to cure AIDS and lupus at a single stroke (and as someone who works in immunology - ok, im-fucking-possible!).

To some minor extent, this still holds true in the primary scientific literature (Science/Nature/obscure journals beyond mention). You're not going to get a paper published by saying in the discussion "Well, the data is kind of interesting but there won't be any practical results for centuries". But at least in the primary literature, the speculations about future practical results at least adhere to some form of reality. Although most of the primary literature is beyond the means of somebody not associated with a research institution (to get your hands on a single paper may cost you upwards of a hundred dollars), a lot of the really important biology papers are available free of charge on ncbi.nlm.nih.gov under the pubmed searches.

 

[gendanken]

Zyncod:

Okay - thread is dead. But - to finalize the 'media' comments, what I said holds true even for popular science books. No-one publishes a book who is not either dead set against an issue (read: psychologists in the 'nature' issue of the nature/nurture debate) or improbably optimistic about a particular issue. The worst form of this is self-published communiques from universities/research centers. My roommate works at Rockefeller University, and their self-published Scientist magazine describes on the front page how Rockefeller is going to cure AIDS and lupus at a single stroke (and as someone who works in immunology - ok, im-fucking-possible!).

To some minor extent, this still holds true in the primary scientific literature (Science/Nature/obscure journals beyond mention). You're not going to get a paper published by saying in the discussion "Well, the data is kind of interesting but there won't be any practical results for centuries". But at least in the primary literature, the speculations about future practical results at least adhere to some form of reality. Although most of the primary literature is beyond the means of somebody not associated with a research institution (to get your hands on a single paper may cost you upwards of a hundred dollars), a lot of the really important biology papers are available free of charge on ncbi.nlm.nih.gov under the pubmed searches.

I'll keep this in mind.

(100 dollars?!)

Invert_nexus:

Reminds me of a song.
One foot on the platform. And the other foot on the train. I'm going back to New Orleans. To wear that ball and chain.

Reminds me of another one:

Little BoBeep....

I understand. Now, let us give this thread its death certificate, long overdue.
Speaking of Schiavo...