Table of Contents
International Journal of Evolutionary Biology
Volume 2012, Article ID 708980, 11 pages
Review Article

Repeated Evolution of Testis-Specific New Genes: The Case of Telomere-Capping Genes in Drosophila

1UMR 5534, Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Université Claude Bernard Lyon 1, Université de Lyon, 69622 Villeurbanne, France
2UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Centre National de la Recherche Scientifique, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France

Received 16 February 2012; Accepted 9 May 2012

Academic Editor: Hideki Innan

Copyright © 2012 Raphaëlle Dubruille et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Comparative genome analysis has allowed the identification of various mechanisms involved in gene birth. However, understanding the evolutionary forces driving new gene origination still represents a major challenge. In particular, an intriguing and not yet fully understood trend has emerged from the study of new genes: many of them show a testis-specific expression pattern, which has remained poorly understood. Here we review the case of such a new gene, which involves a telomere-capping gene family in Drosophila. hiphop and its testis-specific paralog K81 are critical for the protection of chromosome ends in somatic cells and male gametes, respectively. Two independent functional studies recently proposed that these genes evolved under a reproductive-subfunctionalization regime. The 2011 release of new Drosophila genome sequences from the melanogaster group of species allowed us to deepen our phylogenetic analysis of the hiphop/K81 family. This work reveals an unsuspected dynamic of gene birth and death within the group, with recurrent duplication events through retroposition mechanisms. Finally, we discuss the plausibility of different evolutionary scenarios that could explain the diversification of this gene family.