Friday, January 17, 2014

On the function of lincRNAs

There's plenty of evidence that most of the DNA in mammalian genomes is junk [Five Things You Should Know if You Want to Participate in the Junk DNA Debate]. There's also plenty of evidence that as much as 10% of these genomes are functional in some way or another. This is a lot more DNA than the amount in coding regions but that shouldn't surprise anyone since we've known about functional noncoding DNA for half a century.

Lot's of genes specify functional RNA molecules. The best known ones are the genes for ribosomal RNAs, tRNAs, the spliceosomal RNAs, and a variety of other catalytic RNAs. A host of small regulatory RNAs have been characterized in bacteria over the past five decades (Waters and Storz, 2009) and in the past few decades a variety of different types of small RNAs have been identified in eukaryotes (see Sharp, 2009). These include miRNAs, siRNAs, piRNAs, and others (Malone and Hannon, 2009; Carthew and Sontheimer, 2009).

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