Gene expresion adaptation ‘signs’ in!
The review by Hunter Fraser discusses the role of gene expression in adaptation, the challenges facing the field, recent genome-wide studies that allow the rejection of the null model of neutrality and how the latter thus help to determine, with some confidence, if positive selection is occurring. He then goes on to discuss questions that can be addressed and the empirical evidence available for answering these. Challenges in studying gene expression adaptation: The author discusses the two important stages at which adaptation can occur – the inherent sequences of proteins and the pattern and level of expression of these proteins. Protein sequence evolution and its role in adaptation have received a lot of attention from the scientific community and have been widely studied. The study of gene expression adaptation (GEA) on the other hand, has been very limited. There are three reasons for this aberration – the little significance attributed to GEA in adaptation as compared to protein sequences until recently (as recent as 2003!), difficulty to characterize gene regulation as compared to deducing DNA sequences, mainly because of its dynamic nature, and thus the unavailability of suitable methods for simple and effective study of GEA. On these lines, the …
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