Talk:Gene/Archive 1

How does BSE and Scrapie have 0 DNA? --Anon
 * Both BSE and Scrapie are caused by a type of rogue protein complex that biologists call prions. Prions work in a similar manner as enzymes except their catalitic action is directed at reshaping certain types of large proteins found in the host organism to be a copy of themselves -- thus reproducing without the need for DNA. Scrary stuff if you ask me. BTW, in the future, please post your comments in the Talk: page - we like to keep comments out of the main articles. --maveric149

Does anyone know when the data on this page is from? I'm learning about this in Biology class, and we were taught that humans only have 30,000 genes (and, indeed, that earlier estimates of greater numbers were wrong). I'd change it, but I know nothing compared to some of the people who visit this site. -- bdesham

30000 or 35000 makes very little differences...compared to previous suggested numbers :-) Last time I heard (2002 public governmental research), estimates were around 35000, Réseau GenHomme sources.

user:anthere

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If "by Gregor Mendel...explained his results in term of genes," how could the term have been invented only in 1909 as asserted in the first sentence of this entry?

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 * You can read Mendel's work here. He doesn't use the term 'gene', but he did develop the idea of independent assortment of traits. I don't think it's fair to characterize Mendel's work as an explanation of his results in terms of genes, though you'd have to read his work more carefully than I did to be sure. Graft

Somebody commented that changes I made decreased the precision of some earlier version. I don't know which version or what you meant. Maybe I've done better with the latest changes. What got me started on this article was the allusion to precision in its first line. "Gene" really isn't precise. It's squirrelly even as molecular biologists use it. I wouldn't be surprised if philosophers of science had conferences about this.

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P.S. To me it's wrong to say a gene "contains information in the form of sequences of nucleotides...drawn from a universal code," if you mean "drawn" in the sense of "emerging." That's like saying the sequence of letters in "Hamlet" contains information drawn from English. The information is expressed in and understood using the rules and vocabulary of English. But Shakespeare didn't pluck "Hamlet" from English. Maybe you can improve on the tack I took, but I don't think you do with "drawn." BTW I meant the clause in question to tie to a later clause and explain how the info in a gene _specifies_ a protein.


 * Well, let's take this slowly then. Your new 2nd sentence is: "It contains information in the form of a sequence of nucleotides--especially DNA sequences--which according to a universal code that is recognized with only minor variations across all forms of life, including viruses, specifies the amino-acid sequence of a protein." This is very confusing. The reader must look back and forth to discover what exactly the words "which according" refer to. Also, the use of the words "a protein" at the end make it look as if one gene=one protein, which is rarely the case. I am changing the sentence to: "It contains information in the form of a sequence of nucleotides--especially DNA sequences--conforming to a universal code that is recognized with only minor variations across all forms of life, including viruses. This DNA sequence (a "gene") in turn specifies the amino-acid sequences of proteins." JDG 23:40 Jan 16, 2003 (UTC)

I guess I have to accept that it confuses if you say it does. [Deleted comments I realized were wrong on better thought] But I don't think "conforming to" is quite right for this either. It leaves things vague: "The sequence of letters in Hamlet contains information _conforming_ to the vocabulary and rules of English...which in turn specifies a sequence of events." How did the letters in Hamlet specify it? So what if they conform? I'm giving it another go.

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Hey 168- what was nonsensical about the prion comment? They contain no DNA or RNA yet by some definitions are "alive" JDG

The sentence implied that prions might not recognize the genetic code, but even if you want to entertain the notion that prions are a form of life (notwithstanding my unfortunate use of "including" in that sentence, no biologist I've ever met spoke of even viruses as "alive"), prions don't have ribosomes so it makes no sense to suppose one could read a gene sequence, recognize the genetic code and translate it. I meant "recognize" in the context of the way genes--defined as sequences--get used. If prions are life or if they are genes, they don't fit the sequence definition, b/c they don't replicate their sequences, they replicate their conformations. Prion disease epidemics have begun when one person's mutant prion gene, which unnaturally predisposed its protein product to assume the pathogenic conformation, infects another individual, where it melds that person's healthy-sequence prions into the pathogenic shape. PLus there's the famous frequent leaping of the species barrier. The prion leaps but the sequence doesn't.

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 * well you sure know some persnickety biologists. Biologists I've known and read come down at least 5 to 1 on the side of including viruses under the rubric of "life", most notably Christian de Duve, 1974 Nobel winner... The fact that prions don't have ribosomes or any of the other familiar machinery of inheritance and protein production is exactly the point: if they are considered "alive" they then constitute a living entity which does not employ the code you claim is "universal". Since there is heated debate over whether they are indeed "alive", my sentence (..."with the possible exception of prions"...) was, I believe, correct. But I won't press the issue. I think though that you should get into the habit of acknowledging views held by qualified people who happen to disagree with you. JDG

I made some changes to the first paragraph, partly editorial, partly content. In terms of content, I specified that genes have two crucial functions, encoding the template for the production of proteins, and turning the production of proteins on and off. I also worked Mendel in -- I think he is too important to leave out of the first paragraph. Finally, I rewrote the last sentence. Gene's do not "generate" proteins, if "generate" means to bring into being or produce (as my American Heritage dictionary claims). Gene's "make" nothing -- proteins are "made" by a complex machinery that includes other proteins. Genes are, absolutely, an important, necessary part of this machinery. But genes can neither produce proteins, nor reproduce themselves, alone -- they require the rest of the machinary. In short, they are a crucial part of whatever it is that generates the building-blocks of life -- but they do not generate by themselves. Slrubenstein


 * hey SLR, how you been?... It seems our fate is to debate. First off, could you take a little greater care before punching the Save button? Your edits almost always have what look like rush-induced errors. When someone (like me) goes in to clean it up, it's tempting to start changing this and that-- so you unnecessarily open yourself to getting rewritten... Secondly, I'd have to disagree on the "generate" issue. "Generate" is usually used to denote the prime mover of some occurrence, and here we would have to assign that role to the stretches of DNA known as genes. A power generating plant does not contain transmision lines, tranformers, end-user circuit breakers, etc., yet is correctly thought of as a "generator". In most living cells, DNA (genes) initiate and prescribe the building of proteins-- mRNA and tRNA bustle out of the nucleus to do the work, but the nuclear DNA occupies the place of generator... I agree completely that Mendel should be in the first paragraph, but the paragraph at the moment needs to cleaned up. JDG

Doing alright; you seem to be at the top of your form. Sorry about the typos -- I thought I caught them. As for "generate," I guess we are destined to disagree. Must be something in our genes. I think your analogy is misplaced -- I would not compare a gene to a power generating plant, and the other chemicals and proteins required for the manufacture of proteins to the transmission lines and transformers. I would compare the gene to one part of the power generating plant, and the proteins involved to other parts of the plant. If I were to compare anything to powerlines and transformers, I would call that the "environment" in which protein manufacture takes place -- for example, the presene of sugar lactose in the environment of coliform bacteria that triggers the production of proteins necessary to break down the lactose. In some sense that sugar is "necessary" to the production of proteins, but of course I (and I am certain you) would not consider this part of the "generating machinary" of the proteins. In other words, I grant that your metaphor has some use, but I use it in a different way than you.

I honestly do not see this as a humongous debate. I am sure many biologists see it as you do; I am sure many others see it as I do. Do you really think the sentence I wrote ("crucial to the generation" is so misleading and detrimental to the education of lay-people? I thought that phrasing (I mean, crucial is pretty serious, isn't it?) would be something all parties could agree on. Slrubenstein