The evolution of complexity
Where does this leave the issue of how to account for the complexity of higher organisms? (Let us put aside the question of how exactly complexity is defined, on the grounds that we can probably all agree that on any relevant criteria a human being is more complex than a nematode worm.) One implication of the van Bakel et al. paper is that there are more exons in the genome than we know about, which would imply more complexity than has yet been tallied in the protein universe. Nor has it been demonstrated by any rigorous computation that combinatorial control of gene expression by protein complexes is insufficient to support the regulatory complexity required to make a human (to which alternative splicing of coding RNAs is likely to make a significant contribution - see for example[11]). However it is clear that even if alternatively spliced and combinatorially interacting proteins were in principle adequate to the task, in practice that is not the sole regulatory resource, and there do indeed exist regulatory RNAs, some quite well understood, others much less well (see [5]). Regulatory RNAs of course also exist in bacteria, where they have been known for 30 years and have a considerable diversity of functions that are much better understood than the more recently discovered eukaryotic ones, and indeed richly illustrate the regulatory modes to which RNA lends itself [12] - a fact that Mattick does not mention in his Q&A for BMC Biology but has acknowledged clearly in other publications (see for example [8]). However there is already known to be quantitatively more regulatory RNA in mammals, even without the unexplained non-coding transcripts that have emerged from transcriptomics.
+++++
Editorial
The evolution of gene regulation, the RNA universe, and the vexed questions of artefact and noise
Miranda Robertson
BMC Biology 2010, 8:97doi:10.1186/1741-7007-8-97
The electronic version of this article is the complete one and can be found online at:http://www.biomedcentral.com/1741-7007/8/97
Received: 13 July 2010
Accepted: 13 July 2010
Published: 16 July 2010
© 2010 Robertson; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
+++++
FREE PDF GRÁTIS [239 KB]
+++++
Vote neste blog para o prêmio TOPBLOG.
