Abstracts (first author)
Co-divergence between bacteria and host: Consequences of Wolbachia infection in the Chorthippus parallelus hybrid zone
Divergence between two subspecies of the grasshopper Chorthippus parallelus has been extensively studied for evolutionary purposes. They form a hybrid zone in the Pyrenees between the Iberian endemic subspecies C. p. erythropus and the continental European subspecies C. p. parallelus (1). Wolbachia infection in pure and hybrid individuals of these subspecies has been characterized by PCR analysis of their 16S rRNA sequences and a Multi-Locus Strain Typing System (MLST) (2). Phylogenetic and phylogeographic studies based on previous host phylogeny, as well as this MLST approach, show that Wolbachia co-diverges with its host. In addition, extrapolation of the divergence time between bacterial strains allows us to propose than Wolbachia infected C. parallelus during host speciation. This fact, joint to the cytoplasmic incompatibility and other effects induced by this bacterium in natural populations of C. parallelus (3, 4) support that co-divergence between bacteria and host contributes to explain the current situation of the hybrid zone.
(1) Shuker DM, et al. 2005. “The genetic basis of speciation in a grasshopper hybrid zone”. En “Insect Evolutionary Ecology”. CABI Publishing, Oxford University Press, pp 427-454. ISBN 0851998127. (2) Baldo L, et al. 2006. Multilocus Sequence Typing System for the Endosymbiont Wolbachia pipientis. Appl Environ Microbiol 72:7098-7110. (3) Bella, J.L, Martínez-Rodríguez, P., Arroyo-Yebras, F., Bernal, A., Sarasa, J., Fernández-Calvín, B, Mason, P.L. & Zabal-Aguirre, M. 2010. “Wolbachia infection in the Chorthippus parallelus hybrid zone: evidence for its role as a reproductive barrier”. Journal of Orthoptera Research, 19 (2): 205-212. (4) Sarasa, J., Bernal, A., Fernández-Calvín, B. & Bella, J.L. 2013. Wolbachia induced cytogenetical effects, as evidenced in Chorthippus parallelus (Orthoptera). Cytogenetic and Genome Research 139: 36–43.