Re: Science Daily~Scientifically Rethinking Fungi's Abilitie
Posted by Deborah on 3/18/10
Thanks Sharon, that is an very interesting article. I
suspected this but had no way to verify.
I wonder if unleashing so many chemicals into the world has
had anything to do with their increased rate of adaptability
and transference.
On 3/18/10, Sharon wrote:
> "..this study we found fungi able to transfer an infectious
> capability to a different strain in a single generation,"
> he said. "We've probably underestimated this phenomenon,
> and it indicates that fungal strains may become pathogenic
> faster than we used to think possible."
>
>
>
> "..suggests that fungi have the capacity to rapidly change
> the make-up of their genomes and become infectious to
> plants and possibly animals, including humans."
>
> "...evolution of virulence in fungal strains that was once
> believed to be slow has now been shown to occur quickly,
> and may force a renewed perspective on how fungi can
> behave, change and transfer infectious abilities."
>
>
>
> ScienceDaily (Mar. 17, 2010) — Fungi have significant
> potential for "horizontal" gene transfer, a new study has
> shown, similar to the mechanisms that allow bacteria to
> evolve so quickly, become resistant to antibiotics and
> cause other serious problems.
>
> This discovery, to be published March 18 in the journal
> Nature, suggests that fungi have the capacity to rapidly
> change the make-up of their genomes and become infectious
> to plants and possibly animals, including humans.
>
> They are not nearly as confined to the more gradual
> processes of conventional evolution as had been believed,
> scientists say. And this raises issues not only for crop
> agriculture but also human health, because fungi are much
> closer on the "evolutionary tree" to humans than bacteria,
> and consequently fungal diseases are much more difficult to
> treat.
>
> The genetic mechanisms fungi use to do this are different
> than those often used by bacteria, but the end result can
> be fairly similar. The evolution of virulence in fungal
> strains that was once believed to be slow has now been
> shown to occur quickly, and may force a renewed perspective
> on how fungi can behave, change and transfer infectious
> abilities.
>
> "Prior to this we've believed that fungi were generally
> confined to vertical gene transfer or conventional
> inheritance, a slower type of genetic change based on the
> interplay of DNA mutation, recombination and the effects of
> selection," said Michael Freitag, an assistant professor of
> biochemistry and biophysics at Oregon State University.
>
> "But in this study we found fungi able to transfer an
> infectious capability to a different strain in a single
> generation," he said. "We've probably underestimated this
> phenomenon, and it indicates that fungal strains may become
> pathogenic faster than we used to think possible."
>
> Researchers from the Center for Genome Research and
> Biocomputing at OSU collaborated on this study with a large
> international group of scientists, including principal
> investigators from The Broad Institute in Massachusetts,
> the University of Amsterdam, and the USDA Agricultural
> Research Service at the University of Minnesota.
>
> Bacteria use "horizontal" genetic transfer through
> chromosomes and DNA plasmids to change quickly, which is
> one reason that antibiotic resistance can often develop.
> This capability was believed to be possible, but rare, in
> fungi. In the new study, based on a genome-wide analysis of
> three Fusarium species, it was shown experimentally that
> complete chromosomes were being transferred between
> different fungal strains, along with the ability to cause
> infection. Various Fusarium fungi can infect both plants
> and humans.
>
> In humans, fungal infections are less common than those
> caused by bacteria, but can be stubborn and difficult to
> treat -- in part, because fungi are far more closely
> related to animals, including humans, than are bacteria.
> That limits the types of medical treatments that can be
> used against them. Fungal infections are also a serious
> problem in people with compromised immune systems,
> including AIDS patients, and can be fatal.
>
> According to Freitag, this new understanding of fungal
> genetics and evolution is great news.
>
> For one thing, it may help researchers to better understand
> the types of fungal strains that are most apt to develop
> resistance to fungicides, and help crop scientists develop
> approaches to minimize that problem.
>
> Fungal diseases are a major problem in crop agriculture,
> and billions of dollars are spent around the world every
> year to combat new and emerging fungal pathogens in plants,
> animals and humans.
>
> On a more basic level, this study provides evidence that
> the "tree of life," with one trunk and many branches, is
> outdated. It should be replaced by a "network of life" in
> which many horizontal connections occur between different
> species.
>
>
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