Insecticide-resistant Myzus persicae as an example of evolution by gene duplication

Abstract

DUPLICATION of structural genes is believed to be a prerequisite for evolution because it allows forbidden mutations of the redundant copy while preserving the advantageous parental gene^1,2. Evidence for this phenomenon is derived from studies of proteins with closely related structures which fulfil either slightly or very different roles in metabolism. The first stage of the process, duplication without subsequent mutation, leads to the production of more of a particular gene product. This is especially advantageous during development, when large amounts of ribosomal and transfer RNA are required³. However, so far the only examples of this mechanism causing increased production of specific proteins in response to changing environmental conditions are from studies of bacteria⁴, yeast⁵ and eukaryotic cell cultures⁶. Using insecticide-resistant Myzus persicae, we provide evidence here for gene duplication without subsequent mutation, conferring a definite selective advantage to intact higher organisms in adverse environmental conditions.