Eukaryotic genomes as RNA machines

Eukaryotic genomes appear to be "RNA machines" ¹, in the sense that they are almost entirely transcribed, generating a large number of non coding RNAs. Interestingly, some (a yet unknown percentage) perform important regulatory functions and have been shown to exhibit cell type-specific expression, localization to subcellular compartments, and association with human diseases, suggesting that these transcripts may not just represent "transcriptional noise". As only a minority of the myriad of transcripts originating from eukaryotic genomes have been characterized, the extent of their functional relevance (i.e how many of these transcripts serve a role) is currently unknown.

While reading for a class I have to give next week, I came across with a nice way to describe this fascinating finding about eukaryotic genomes:

"If RNA types were to have their own color, each eukaryotic genome would continuously be emitting a riot of hues, with some regions radiating across the entire spectrum as, for example, development unfolds" ²

What a beautiful way to put it...

[Image credit: Ru Tover]

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¹Amaral PP, Dinger ME, Mercer TR, Mattick JS (2008) The eukaryotic genome as an RNA machine. Science 319(5871):1787-9.

²Ponting CP, Oliver PL, Reik W (2009) Evolution and functions of long noncoding RNAs. Cell 136(4):629-41.