Whence river blindness? The domestication of mammals and host-parasite co-evolution in the nematode genus Onchocerca. Issue 8 (July 2017)

• Record Type: Journal Article
• Authors: Lefoulon, Emilie; Giannelli, Alessio; Makepeace, Benjamin L.; Mutafchiev, Yasen; Townson, Simon; Uni, Shigehiko; Verocai, Guilherme G.; Otranto, Domenico; Martin, Coralie
• Is Part Of: International journal for parasitology. Volume 47:Issue 8(2017)
• Page Start: 457
• Page End: 470
• Publication Date: 2017-07
• Subjects: Onchocerca -- Filariae -- Phylogeny -- Diagnostic marker -- Host-switching -- Domestication -- Wolbachia -- Co-evolution; Parasitology -- Periodicals; Parasitology -- Periodicals; Parasitologie -- Périodiques; Parasitology; Periodicals; Electronic journals; 571.999
• DOI: 10.1016/j.ijpara.2016.12.009
• Languages: English
• ISSNs: 0020-7519

Abstract

Graphical abstract: Highlights: coxI is a suitable marker for the identification of Onchocerca spp. Multi-gene phylogeny reveals three strongly supported clades of Onchocerca . Recent host switch events between Bovidae, Canidae and humans are observed. Potential role for the domestication of cattle in Onchocerca speciation. Cophylogenetic analyses of Onchocerca / Wolbachia show the strongest coevolution. Abstract: The genus Onchocerca includes 34 described species and represents one of the largest genera of the filarial nematodes within the family Onchocercidae. Representative members of this genus are mainly parasites of ungulates, with some exceptions such as Onchocerca lupi and Onchocerca volvulus, infecting carnivores and/or humans. For a long time, the evolutionary relationships amongst onchocercids remained poorly studied, as the systematics of this genus was impaired by the high morphological variability of species included in the taxon. Although some molecular phylogenies were developed, these studies were mainly focused on bovine Onchocerca spp. and O. volvulus, including assessments of Wolbachia endosymbionts. In the present study, we analysed 13 Onchocerca spp. from a larger host spectrum using a panel of seven different genes. Analysis of the cox I marker supports its usefulness for the identification of species within the genus. The evolutionary history of the genus has been herein revised by multi-gene phylogenies, presenting three strongly supported clades of Onchocerca spp. Analyses of co-evolutionary scenarios between Onchocerca and their vertebrate hosts underline the effect of domestication on Onchocerca speciation. Our study indicates that a host switch event occurred between Bovidae, Canidae and humans. Cophylogenetic analyses between Onchocerca and the endosymbiotic bacterium Wolbachia indicate the strongest co-evolutionary pattern ever registered within the filarial nematodes. Finally, this dataset indicates that the clade composed by O. lupi, Onchocerca gutturosa, Onchocerca lienalis, Onchocerca ochengi and O. volvulus derived from recent speciation.