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nidthamsirisup

Mysterious Noncoding DNA: 'Junk' or Genetic Power Player? | PBS NewsHour - 0 views

www.pbs.org/...junk-dna.html

noncoding DNA gene

shared by nidthamsirisup on 15 Apr 12 - No Cached
  • Genes represent only a tiny fraction -- 1 percent -- of our overall genetic material. Then there's the other 99 percent of our DNA -- the stuff that doesn't make protein
  • Researchers have found that some of this noncoding DNA is in fact essential to how our genes function and plays a role in how we look, how we act and the diseases that afflict us.
  • Embedded in this 99 percent is DNA responsible for the mechanics of gene behavior: regulatory DNA. Greg Wray of Duke University's Institute for Genome Sciences and Policy describes the regulatory DNA as the software for our genes, a set of instructions that tells the genome how to use the traditional coding genes.
  • ...5 more annotations...
  • "It's like a recipe book," Wray said. "It tells you how to make the meal. You need to know the amounts. You need to know the order. The noncoding DNA tells you how much to make, when to make it and under what circumstances."
  • common diseases are probably more influenced by regulatory differences, Harismendy said. These include Type 2 diabetes, Crohn's disease, Alzheimer's Disease and a variety of cancers, including breast, colon, ovarian, prostate and lung.
  • According to Wray, research has shown that diseases like bipolar syndrome and clinical depression may be associated with noncoding mutations that determine whether the brain is producing too much or not enough of a particular neurotransmitter. One noncoding mutation gives a person almost complete protection against the nasty malaria parasite, plasmodium vivax.
  • Another piece of noncoding DNA regulates the enzyme responsible for lactose tolerance, the ability to digest milk. Research by Wray and other scientists has shown that in four populations where dairy consumption is a vital part of the diet, new mutations have appeared that essentially keep the gene that produces the lactase enzyme from switching off.
  • And recent research done by evolutionary biologists suggests that differences in regulatory DNA may represent a major part of what separates us from chimpanzees.
orasa sukmark

Junk DNA Can Revive and Cause Disease, Study Finds - NYTimes.com - 0 views

www.nytimes.com/...20gene.html

shared by orasa sukmark on 30 Mar 12 - No Cached
  • can rise from the dead like zombies
  • dead gene come back to life and cause a disease
  • a dead gene come back to life and cause a disease.
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  • Some of those genes, surprised geneticists reported Thursday, can rise from the dead like zombies, waking up to cause one of the most common forms of muscular dystrophy.
    • adisa narula
      adisa narula on 30 Mar 12
       
      Do these genes revive automatically?
  • It is a dominant genetic disease.
  • people who have the disease cannot smile.
  • FSHD affects about 1 in 20,000 people
  • function, if any, is largely unknown.
  • function, if any, is largely unknown
  • FSHD, is one of the most common forms of muscular dystrophy.
  • in a way FSHD was the easy case — it is a disease that affects every single person who inherits the genetic defect. Other diseases are more subtle, affecting some people more than others, causing a range of symptoms.
  • The dead gene was also repeated on chromosome 10, but that area of repeats seemed innocuous, unrelated to the disease. Only chromosome 4 was a problem.
  • chromosome 4 was a problem.
  • No one whose dead gene was repeated more than 10 times ever got FSHD
  • it was not completely inactive. It is always transcribed
  • copied by the cell as a first step to making a protein.
  • But the transcriptions were faulty, disintegrating right away. They were missing a crucial section, called a poly (A) sequence, needed to stabilize them.
  • But the transcriptions were faulty, disintegrating right away. They were missing a crucial section, called a poly (A) sequence, needed to stabilize them.
  • extra copies change the chromosome’s structure, shutting off the whole region so it cannot be used.
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