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Scientists Discover How To Track Natural Errors In DNA Replication

Posted by samzenpus on from the points-of-failure dept.

BarbaraHudson writes Researchers figured out how to label and keep track of new pieces of DNA, and learned to follow the enzyme responsible for copying those pieces. Their research focused on enzymes called polymerases. These enzymes create small regions in DNA that act as scaffolds for the copied DNA. Scientists assumed that the body deletes the scaffolds containing errors, or mutations, and the standard computer models supported this theory. However, the actual research showed that about 1.5 percent of those erroneous scaffolds are left over, trapped within the DNA. After running models, scientists now believe they can track how DNA replicates and find the most likely areas where these scaffolds with errors turn up. The erroneous scaffolds usually appear close to genetic switches, those regions that turn on when genes activate. The mutations damage the switch, which results in genetic disease, as well as increasing the likelihood of cancer.

8 of 19 comments (clear)

  1. It's amazing... by smaddox · · Score: 3, Insightful

    It's amazing that we're able to learn so much (regardless of how little it really is) about something so mind-bogglingly complicated. Biological processes make quantum mechanics look like child's play.

    1. Re:It's amazing... by BarbaraHudson · · Score: 1

      Look at the medical advances over the last 30 years, and it's kind of hard to imagine where we're going to be in another 30.

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      "Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
  2. Ha! by The+Wild+Norseman · · Score: 1

    Scientists Discover How To Track Natural Errors In DNA Replication

    "Scientists"?! Yeah, "scientists" from the NSA, maybe!!!! Those fuckers will stop at NOTHING to track every damn little thing and now this?! What did poor little DNA ever do to you, you fascist bastards?!

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    "A government is a body of people usually -- notably -- ungoverned." -Shepherd Book
  3. Problem for Evolution by labnet · · Score: 1

    Isn't this a problem for Evolution proponents.
    Evolution requires that beneficial DNA mutations win out over non-beneficial.

    Lets say DNA is like a self replicating VM. The VM has built in error correction but occasionally a copy error occurs. The premise of evolution, is this copy error is occasionally beneficial and the non beneficial errors eventually die out, but the spectrum of copy errors can cause vastly different outcomes. Sometimes a copy error may change an eye color, or cause a miscarriage.
    The question is, does the rate of beneficial mutations outweigh the rate of non-beneficial so the NEW functionality is created and functional entropy is halted?
    My pragmatic side says, If I changed random bytes in a VM, I wouldn't eventually get a facial recognition system, I'd get slowly decaying VM.
     

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    1. Re:Problem for Evolution by sjames · · Score: 1

      The part you're missing is selection. The harmful mutations either fail to reproduce altogether or they reproduce at a lower rate than the good ones. Actual experiments show that you can actually randomly mutate a program and if you have a good selection function, you can actually evolve new functionality.

      The catch is that the evolution tends to 'find' really odd solutions.

    2. Re:Problem for Evolution by Anonymous Coward · · Score: 1

      http://www.nature.com/nature/journal/v485/n7396/full/nature10995.html

      "Evidence of non-random mutation rates suggests an evolutionary risk management strategy"

      http://www.the-scientist.com/?articles.view/articleNo/27910/title/Are-mutations-truly-random-/

      "Do genetic mutations really occur at random spots along the genome, as researchers have long supposed? Maybe not, according to a study published online today (January 13) in Proceedings of the Royal Society B, which proposes a mechanism for how new mutations might preferentially form around existing ones."

      The general consensus has been that there are "hot spots" that experience more DNA mutations than other areas. These usually have markers, such as "pseudo-genes", where the genetic code is more likely to be altered. It has been assumed by some that some time around 65 million years ago, current species all simultaneously experienced a kind of locking in of genetic code so that we don't have much change in those last 65 million years, compared to say the Cambrian Explosion very early on.

      Hope that helps a bit with your line of thinking.

      Ultimately, one big issue isn't with rate of mutation in a certain area, but something that has caused studies to be done about the rate of simultaneous mutation. If we breed a sexually reproducing organism that has experienced a mutation back with the general population that does not share that mutation, it tends to "breed out" that mutation. Hybrids are formed and then the trait is basically lost.

      We see this in White Tigers, in that it isn't actually albinism, but a certain trait that appears that creates the white coloration. If those white tigers are bred back with the general tiger population, the trait is lost, so we have to inbreed the tigers. This has been considered inhumane and banned in most countries.

      We've also see media icon Neil Tyson tweet about "which came first, the chicken or the egg" about which he said that something that was "not quite a chicken" came before. Several people pointed out that something that is a significant variation from another species will either not be able to produce viable offspring with the existing population, or will have that odd trait bred out of a line.

      And that's why research has been done to try to find a reason for multiple simultaneous mutations to occur in order to explain mutations that are necessarily complex enough that they would not survive breeding back with the general population. It's all part of the ongoing "irreducible complexity" arguments that have led into some wild theories being claimed as "proven" when they have not. One instance of this is in the Dover trials with Professor Behe, where the lawyers not only used straw-man arguments against Behe, but also made claims that "co-opting" genetic material was generally accepted as fact, when it is far from it.

      http://www.discovery.org/a/14251
      "The NCSE, Judge Jones, and Citation Bluffs About the Origin of New Functional Genetic Information" - Casey Luskin, Evolution News & Views, March 2, 2010

    3. Re:Problem for Evolution by BarbaraHudson · · Score: 2

      Of course, there's also the fact that each of us harbors about 60 mutations - stuff we didn't inherit from either parent.

      --
      "Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
    4. Re:Problem for Evolution by labnet · · Score: 1

      Those are interesting points.

      I read 'Darwins Black Box' by Behe many years ago, and thought he made good rational arguments about irreducible complexity.

      When a genetic mutation occurs, there will be a continuum of effect, from new feature to no effect to death.
      Natural selection will only have a certain forcing effect that is weighted to the 'death' end of the scale.

      The problem I have with evolution, is the vast majority of any random mutation will be non beneficial and that this process will happen faster than natural selection can remove these defects from the population.

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