Wednesday, April 10, 2013

Evolution and Junk DNA in Chicago

I just signed up for the SMBE Conference in Chicago in July. There's lots of cool talks about evolution but, in the end, I decided I just couldn't miss the session on "Where did 'junk' go?" with Wojciech Makalowski as organizer. Here's the blurb ...
Late Susumu Ohno once said "So much junk DNA in our genome" and the phrase junk DNA was born. For a long time mainstream scientists avoided these parts of the genome. However, over the years the picture slowly started to appear suggesting that the junk DNA hides a genomic treasure. With the completion of the current ENCODE project, junk DNA effectively disappeared because there's no longer useless DNA in the genome. This symposium will discuss the current understanding of these not-so-long-ago obscure areas of the genome, with special attention to transposable elements' activities and their evolutionary consequences. The integral part of the symposium will be general discussion of Ohno’s idea and its place in today's biology.
I'm familiar with Makalowski's way of thinking—it resembles the opinions of many Intelligent Design Creationists even though Makalowski is not a creationist [see Junk DNA: Scientific American Gets It Wrong (again)]. Back in 2007 he said,
Although very catchy, the term "junk DNA" repelled mainstream researchers from studying noncoding genetic material for many years. After all, who would like to dig through genomic garbage?
We know who's been invited to talk.
  1. Josefa Gonzalez (Institut de Biologia Evolutiva, Barcelona, Spain)
    "Adaptation is the key concept in Evolutionary Biology. Understanding adaptation has important scientific and social implications since adaptation underlies processes such as the ability of species to survive in changing environments, resistance to antibiotics and cancer chemotherapies and host-pathogen interactions, among others.
    However, adaptation is to date a very poorly understood process largely because the current approaches to the study of adaptation are often exclusively based on a priori candidate genes or on searching for signals of selection at the DNA level giving us an incomplete and biased picture of the adaptive process.

    In our lab we aimed at understanding the molecular process of adaptation and its functional consequences. Towards this end, we study recent transposable element (TE)-induced adaptations in Drosophila melanogaster."
  2. Valer Gotea (National Human Genome Institute, Bethesda, USA)
    "... it is not surprising that TEs [transposable elements] have a significant influence on the genome organization and evolution. What once was called junk now is considered a treasure. Although much progress has been achieved in understanding of a role that TEs play in a host genome, we are still far from a full understanding of the delicate evolutionary interplay between a host genome and the invaders"
  3. Dan Graur (University of Houston, Houston, USA)
    "This absurd conclusion was reached through various means, chiefly (1) by employing the seldom used “causal role” definition of biological function and then applying it inconsistently to different biochemical properties, (2) by committing a logical fallacy known as “affirming the consequent,” (3) by failing to appreciate the crucial difference between “junk DNA” and “garbage DNA,” (4) by using analytical methods that yield biased errors and inflate estimates of functionality, (5) by favoring statistical sensitivity over specificity, and (6) by emphasizing statistical significance rather than the magnitude of the effect."
  4. Dixie Mager (University of British Columbia, Canada)
    "The fact that transposable elements (TEs) can influence host gene expression was first recognized more than 50 years ago. However, since that time, TEs have been widely regarded as harmful genetic parasites-selfish elements that are rarely co-opted by the genome to serve a beneficial role. Here, we survey recent findings that relate to TE impact on host genes and remind the reader that TEs, in contrast to other noncoding parts of the genome, are uniquely suited to gene regulatory functions. We review recent studies that demonstrate the role of TEs in establishing and rewiring gene regulatory networks and discuss the overall ubiquity of exaptation. We suggest that although individuals within a population can be harmed by the deleterious effects of new TE insertions, the presence of TE sequences in a genome is of overall benefit to the population."
  5. Masumi Nozawa (National Genetic Institute, Mishima, Japan)
    (I don't know anything about his work. Can anybody help?


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