Analysis of the Meiotic Segregation in Intergeneric Hybrids of Tilapias

Bezault Etienne, Rognon François, Clota Frédéric, Gharbi Karim, Baroiller Jean-François, Chevassus Bernard. 2012. Analysis of the Meiotic Segregation in Intergeneric Hybrids of Tilapias. International Journal of Evolutionary Biology, 2012 (ID 817562), 10 p.

Résumé : 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.

Mots-clés Agrovoc : Sarotherodon melanotheron, Oreochromis niloticus, hybridation intergénérique, génome, ségrégation, méiose, génie génétique, microsatellite, Cichlidae, évolution

Classification Agris : M12 - Production de l'aquaculture
L10 - Génétique et amélioration des animaux

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Bezault Etienne, INRA (FRA)
• Rognon François, INRA (FRA)
• Clota Frédéric, CIRAD-PERSYST-UMR INTREPID (FRA)
• Gharbi Karim, INRA (FRA)
• Baroiller Jean-François, CIRAD-PERSYST-UMR INTREPID (FRA) ORCID: 0000-0002-0992-1725
• Chevassus Bernard, INRA (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/574032/)

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