High Levels of Admixture in <i>Anopheles gambiae</i> Populations from Côte d’Ivoire Revealed by Multilocus Genotyping
Naminata Tondossama,
Zanakoungo I. Coulibaly,
Issouf Traoré,
Bérenger A. Ako,
Danielle D. Zoh,
Chiara Virgillito,
Négnorogo Guindo-Coulibaly,
Paola Serini,
Fabrice K. Assouho,
Ibrahima Dia,
Andre O. Touré,
Maurice A. Adja,
Beniamino Caputo,
Alessandra della Torre,
Verena Pichler
Affiliations
Naminata Tondossama
Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
Zanakoungo I. Coulibaly
Entomology and Herpetology Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
Issouf Traoré
Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
Bérenger A. Ako
Malaria Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
Danielle D. Zoh
Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
Chiara Virgillito
Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
Négnorogo Guindo-Coulibaly
Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
Paola Serini
Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
Fabrice K. Assouho
Institut Pierre Richet/Institut National de Santé Publique, Bouaké 01 BP 1500, Côte d’Ivoire
Ibrahima Dia
Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, Dakar BP 220, Senegal
Andre O. Touré
Malaria Unit, Institut Pasteur de Côte d’Ivoire, Abidjan 01 PB 490, Côte d’Ivoire
Maurice A. Adja
Laboratoire de Biologie et Santé, UFR Biosciences, Université Félix Houphouet Boigny Cocody, Abidjan 01 BP V34, Côte d’Ivoire
Beniamino Caputo
Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
Alessandra della Torre
Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
Verena Pichler
Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma “La Sapienza,” Piazzale Aldo Moro, 5, 00185 Rome, Italy
Anopheles coluzzii and An. gambiae—the two most recently radiated species of the An. gambiae complex and the major Afrotropical malaria vector species—are identified by markers in the X-centromeric IGS rDNA region. Putative IGS-hybrids are rarely found in the field, except in restricted areas where genomic studies have led to the hypothesis that the observed IGS-patterns are due to cryptic taxa rather than to hybridization between the two species. We investigated the genome-wide levels of admixture in two villages in Côte d’Ivoire where high levels of IGS-hybrids have been detected, confirming unparalleled high frequencies in the coastal village. Genotyping of 24 Ancestry Informative Markers (AIMs) along the three chromosomes produced discordant results between the IGS-marker and the multilocus genotype obtained for AIMs across the whole genome (29%) as well as AIMs on chromosome-X (considered to be fundamental for species reproductive isolation) only (21%). Results highlight a complicated pattern of admixture that deserves deeper genomic analyses to understand better possible underlying causes (from extensive processes of hybridization to the existence of different cryptic taxa), and stress the need of developing advanced diagnostics for An. coluzzii, An. gambiae and putative new taxa, instrumental for assessing taxon-specific epidemiological characters.