The utilization of redundancy by genetic systems

9 February 2007

Ran Kafri
Lahav Lab, Department of Systems Biology
Harvard Medical School


The prevalence of partially redundant genes is a highly characteristic feature of genetic networks. Yet, despite this, the possibility that genetic networks have evolved to exploit redundancy has rarely been examined. In fact, since functional overlaps are predicted to be evolutionary unstable, the consensus holds that redundancy can not be selected for. Contrasting these expectations, a multitude of studies has recently suggested that redundancy is not only conserved but is embedded in intricate regulatory subnetworks. Furthermore, recent evidence shows that functional overlaps are preferentially associated with genes that likely encode essential functions. This evidence suggests the existence of functionalities that exploit redundancy, thereby rendering it evolutionarily selectable. I will discuss these ideas in the context of specific well characterized examples of redundant gene partners. From these examples, by induction and by relying on simple mathematical arguments, I will attempt to hypothesize on the roles and implications of functional overlaps.


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M A Nowak, M C Boerlijst, J Cooke, J M Smith, "Evolution of genetic redundancy", Nature 388:167-71 1997. PubMed

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