title: New genes from old: asymmetric divergence of gene duplicates and the evolution of development.
abstract: Gene duplications and gene losses have been frequent events in the evolution of animal genomes, with the balance between these two dynamic processes contributing to major differences in gene number between species. After gene duplication, it is common for both daughter genes to accumulate sequence change at approximately equal rates. In some cases, however, the accumulation of sequence change is highly uneven with one copy radically diverging from its paralogue. Such 'asymmetric evolution' seems commoner after tandem gene duplication than after whole-genome duplication, and can generate substantially novel genes. We describe examples of asymmetric evolution in duplicated homeobox genes of moths, molluscs and mammals, in each case generating new homeobox genes that were recruited to novel developmental roles. The prevalence of asymmetric divergence of gene duplicates has been underappreciated, in part, because the origin of highly divergent genes can be difficult to resolve using standard phylogenetic methods.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK peter.holland@zoo.ox.ac.uk.
authors.forename: Peter W H
authors.identifier: 0000-0003-1533-9376
authors.initials: PW
authors.lastname: Holland
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.|Molecular Genetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan.
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Marlétaz
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.|Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas/Universidad Pablo de Olavide, 41013 Sevilla, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Maeso
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Dunwell
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.|School of Biological Sciences, University of Essex, Colchester, Essex, UK.
authors.forename: Jordi
authors.initials: J
authors.lastname: Paps
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019143:Evolution, Molecular; D020131:Genes, Duplicate; D005801:Genes, Homeobox; D048788:Growth and Development
keywords: Lepidoptera; Mammalia; Mollusca; genome duplication; homeobox; tandem duplication