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Tree's Leaves Genetically Different From Its Roots

Posted by samzenpus on from the different-parts dept.

ananyo writes "Black cottonwood trees (Populus trichocarpa) can clone themselves to produce offspring that are connected to their parents by the same root system. Now, after the first genome-wide analysis of a tree, it turns out that the connected clones have many genetic differences, even between tissues from the top and bottom of a single tree. 'When people study plants, they'll often take a cutting from a leaf and assume that it is representative of the plant's genome,' says Brett Olds, a biologist at the University of Illinois at Urbana-Champaign who was involved in the study. 'That may not be the case. You may need to take multiple tissues.' The finding also challenges the idea that evolution only happens in a population rather than at an individual level. As one tree contains many different genomes, natural selection and evolution could happen within a single organism."

4 of 80 comments (clear)

  1. Some monkeys are similarly troublesome... by fuzzyfuzzyfungus · · Score: 4, Informative

    Some marmosets are naturally chimeric some substantial portion of the time. This leads to wacky fun for researchers because it is perfectly possible(depending on how the different cell populations ended up distributed in the mature monkey) for an individual to show one genotype on blood tests; but produce offspring that appear to be genetic descendants of their brother or sister....

    Just to be sure, we'll probably have to homogenize any animals and/or small children we wish to study in the future.

    1. Re:Some monkeys are similarly troublesome... by wonkey_monkey · · Score: 5, Informative

      And if anyone's wondering, it happens in humans too. One woman nearly had her kids taken away when DNA tests indicated she wasn't their mother, until it was determined that her reproductive system was from one of her constituent maternal "twins" while her hair and skin (which were sampled for the tests) were from another.

      Mmmm... soup-like homogenate...

      --
      systemd is Roko's Basilisk.
  2. Re:Uh... Howzat? by fuzzyfuzzyfungus · · Score: 4, Informative

    But not quite impossible, interestingly.

    So called Clonally transmissible cancers are particularly growth-oriented cells from some progenitor organism that managed to beat the odds and, instead of just killing their luckless host as cancers tend to, spread to other members of the species.

    There is also Henrietta Lacks; but she lives more or less exclusively in laboratory environments and might not be said to count...

  3. Re:Cancer by wierd_w · · Score: 4, Informative

    Not entirely true.

    There exists a naturally occurring "disease" in dogs that is a sexually transmitted cancer.

    It could be considered a highly successful parasitical mutation of the canid genome, which has evolved to make use of the reproductive behaviors of its host organism to perpetuate itself.

    IIRC, genetic analysis of the genome for the tumor suggests that it is several thousand years old.