Table of Contents
International Journal of Evolutionary Biology
Volume 2012 (2012), Article ID 817562, 10 pages
http://dx.doi.org/10.1155/2012/817562
Research Article

Analysis of the Meiotic Segregation in Intergeneric Hybrids of Tilapias

1UMR110 Cirad-Ifremer INTREPID, 34398 Montpellier, France
2INRA, UMR1313 Génétique Animale et Biologie Intégrative, 78352 Jouy-en-Josas, France
3Department of Biology, Reed College, Portland, OR 97202, USA
4AgroParisTech, UMR1313 Génétique Animale et Biologie Intégrative, 75231 Paris, France
5Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK

Received 31 January 2012; Accepted 26 March 2012

Academic Editor: R. Craig Albertson

Copyright © 2012 Etienne Bezault 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.

Abstract

Tilapia species exhibit a large ecological diversity and an important propensity to interspecific hybridisation. This has been shown in the wild and used in aquaculture. However, despite its important evolutionary implications, few studies have focused on the analysis of hybrid genomes and their meiotic segregation. Intergeneric hybrids between Oreochromis niloticus and Sarotherodon melanotheron, two species highly differentiated genetically, ecologically, and behaviourally, were produced experimentally. The meiotic segregation of these hybrids was analysed in reciprocal second generation hybrid (F2) and backcross families and compared to the meiosis of both parental species, using a panel of 30 microsatellite markers. Hybrid meioses showed segregation in accordance to Mendelian expectations, independent from sex and the direction of crosses. In addition, we observed a conservation of linkage associations between markers, which suggests a relatively similar genome structure between the two parental species and the apparent lack of postzygotic incompatibility, despite their important divergence. These results provide genomics insights into the relative ease of hybridisation within cichlid species when prezygotic barriers are disrupted. Overall our results support the hypothesis that hybridisation may have played an important role in the evolution and diversification of cichlids.