Table of Contents
International Journal of Evolutionary Biology
Volume 2011, Article ID 972457, 7 pages
Review Article

Boule and the Evolutionary Origin of Metazoan Gametogenesis: A Grandpa's Tale

1CHROMEVOL-XENOMAR Group, Departamento de Biología Celular y Molecular, Facultade de Ciencias, Universidade da Coruña, Campus de A Zapateira s/n, E15071 A Coruña, Spain
2Department of Biochemistry and Microbiology, University of Victoria, V8W 3P6 Victoria, BC, Canada V8W 3P6

Received 16 January 2011; Revised 18 April 2011; Accepted 9 May 2011

Academic Editor: Rob Kulathinal

Copyright © 2011 José M. Eirín-López and Juan Ausió. 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.


The evolution of sex remains a hotly debated topic in evolutionary biology. In particular, studying the origins of the molecular mechanisms underlying sexual reproduction and gametogenesis (its fundamental component) in multicellular eukaryotes has been difficult due to the rapid divergence of many reproductive proteins, pleiotropy, and by the fact that only a very small number of reproductive proteins specifically involved in reproduction are conserved across lineages. Consequently, during the last decade, many efforts have been put into answering the following question: did gametogenesis evolve independently in different animal lineages or does it share a common evolutionary origin in a single ancestral prototype? Among the various approaches carried out in order to solve this question, the characterization of the evolution of the DAZ gene family holds much promise because these genes encode reproductive proteins that are conserved across a wide range of animal phyla. Within this family, BOULE is of special interest because it represents the most ancestral member of this gene family (the “grandfather” of DAZ). Furthermore, BOULE has attracted most of the attention since it represents an ancient male gametogenic factor with an essential reproductive-exclusive requirement in urbilaterians, constituting a core component of the reproductive prototype. Within this context, the aim of the present work is to provide an up-to-date insight into the studies that lead to the characterization of the DAZ family members and the implications in helping decipher the evolutionary origin of gametogenesis in metazoan animals.