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Science Forum

  1. 13 Dec '13 19:04
    How much do different species of living things differ in their genetic codon languages for translating into proteins?
    Would, for example, most bacteria have almost exactly the same or identical or completely different codon languages from, say, humans?

    For example, as far as I know, in humans, the codon AUG represents the amino acid Methionine and the codon UGG represents the amino acid Tryptophan.
    Is the same true for most bacteria, fungi, plants and animals? If not, what are the general differences and by how much do they generally differ and can anyone give me a web link to a list of codon languages of other species?

    I spent ages trying to look this up on the net but so far failed to find a single simple straight answer to this simple question.
  2. 13 Dec '13 22:43
    Originally posted by humy
    How much do different species of living things differ in their genetic codon languages for translating into proteins?
    Would, for example, most bacteria have almost exactly the same or identical or completely different codon languages from, say, humans?

    For example, as far as I know, in humans, the codon AUG represents the amino acid Methionine and the codon ...[text shortened]... up on the net but so far failed to find a single simple straight answer to this simple question.
    The genetic code is universal (on earth!) except that some specialised yeast tRNAs have anti-codons not coresponding to the usual codon. Most genetics and biochemistry texts will have a table with the genetic code.
  3. 14 Dec '13 04:31
    I have taken a course on due subject.... \ A pity \ I can't find my old textbook.\ but I DO HAVE other books...

    However.

    Genomes are very complicated things. Since you seem interested in this I will tell you. (Personally I hate when people change the subject in question, but there's always exceptions). Especially in humans, there are a thing (which I can't remember the name on. Have to get back for that little detail). Called something like "several copies of the same gene", i.e. Think a train. The train travelling on the railroad will have many wagons. The wagons are exactly the same. My point beeing, there have only to be 1 promotor (gene transcription starter), to make several RNAs. This thing that humans have this a lot and that other mammals only have this a little is seen as an important step in how humans differentiated themselves from other primates. The "several copies of the same gene" is very important in forensics (which person does this DNA belong to). Since it is the only way. (*That I know of, I mean, the only easy way...). To tell two close relatives apart. / As said. I will get back to you with the name.
  4. 14 Dec '13 09:31
    Originally posted by bikingviking
    I have taken a course on due subject.... \ A pity \ I can't find my old textbook.\ but I DO HAVE other books...

    However.

    Genomes are very complicated things. Since you seem interested in this I will tell you. (Personally I hate when people change the subject in question, but there's always exceptions). Especially in humans, there are a thing (whi ...[text shortened]... asy way...). To tell two close relatives apart. / As said. I will get back to you with the name.
    Oh yes, I know what you are talking about. You are talking about alternative splicing:

    http://en.wikipedia.org/wiki/Alternative_splicing

    I have been reading about this; fascinating subject I think.
  5. 14 Dec '13 09:33 / 5 edits
    Originally posted by twohybrid
    The genetic code is universal (on earth!) except that some specialised yeast tRNAs have anti-codons not coresponding to the usual codon. Most genetics and biochemistry texts will have a table with the genetic code.
    Thanks for that; now I know
    Strange that I cannot find a straight answer to that simple question on my previous and extensive internet searches.

    This would have certain implications for evolution for it would mean:

    1, it must be difficult for organisms to evolve to change their codon language else many of them would have already done so! So, apparently, once an organism evolves a codon language, it is generally forever stuck with that codon language.

    2, the fact that the codon language is universal to virtually all organisms and universal despite it being arbitrary and there being no biological cost of it being different from what it is, is yet further evidence of all life on Earth has common ancestry (not that further evidence of this is needed! )

    It has also occurred to me the potential of artificially changing this codon language in all human cells (this would require replacing the whole genome with one written in the new language AND simultaneously changing all the tRNAs ) in the human body because this will, without any biological cost, instantly make as immune to all naturally occurring viruses because, if any of those viruses invaded such genetically altered cells, there protein-coding genes, being now written by evolution in the wrong language, would be mistranslated to produce junk non-fictional viral proteins instead of well shaped functional ones! It is this thought that is the real motive for my OP.
  6. 14 Dec '13 16:09
    Originally posted by humy
    Thanks for that; now I know
    Strange that I cannot find a straight answer to that simple question on my previous and extensive internet searches.

    This would have certain implications for evolution for it would mean:

    1, it must be difficult for organisms to evolve to change their codon language else many of them would have already done so! So, apparentl ...[text shortened]... ns instead of well shaped functional ones! It is this thought that is the real motive for my OP.
    I agree that the universal genetic code is evidence of the common ancestor cell but, to be honest, I have never come to grips with this finding. Why have there not been no advantageous mutations in gens coding for tRNAs? maybe the simple answwr is, such mutations can never be advantageous.
  7. 14 Dec '13 18:01 / 1 edit
    Originally posted by twohybrid
    I agree that the universal genetic code is evidence of the common ancestor cell but, to be honest, I have never come to grips with this finding. Why have there not been no advantageous mutations in gens coding for tRNAs? maybe the simple answwr is, such mutations can never be advantageous.
    such mutations can never be advantageous.

    generally, yes. But with just one possible exception; it would make a cell resistant to viruses (for the reason I explained in my last post ) -at least for perhaps a few thousand years until the viruses evolve and adapt to the new genetic code.

    Hypothesis:
    could this explain why yeast contains a slightly different codon language? (anyone; is it only 'slightly' different? ) Its ancestor may have once been plagued by virus but then a chance mutation (and I assume a very freak and difficult one to occur ) or, more probably, a series of mutations, made one cell change its codon language giving it an immediate advantage by making it resistant to virus and this became the common ancestor of all yeast cells?
  8. Standard member RJHinds
    The Near Genius
    15 Dec '13 00:14
    Originally posted by humy
    such mutations can never be advantageous.

    generally, yes. But with just one possible exception; it would make a cell resistant to viruses (for the reason I explained in my last post ) -at least for perhaps a few thousand years until the viruses evolve and adapt to the new genetic code.

    Hypothesis:
    could this explain why yeast contai ...[text shortened]... dvantage by making it resistant to virus and this became the common ancestor of all yeast cells?
    You Evilutionists can't seem to understand that there is no genetic evilution. There is only genetic degeneration.
  9. Standard member sonhouse
    Fast and Curious
    15 Dec '13 01:50
    Originally posted by RJHinds
    You Evilutionists can't seem to understand that there is no genetic evilution. There is only genetic degeneration.
    And you are living proof of that. Fortunately the REST of us have gained from evolution.
  10. Standard member mikelom
    Ajarn
    15 Dec '13 04:33
    Originally posted by sonhouse
    And you are living proof of that. Fortunately the REST of us have gained from evolution.
    classic!