Genetic structure of black rat populations in a rural plague focus in Madagascar

• Published in: Canadian Journal of Zoology
• Main Authors: Gilabert, Aude, Loiseau, A., Duplantier, Jean-Marc, Rahelinirina, S., Rahalison, L., Chanteau, S., Brouat, Carine
• Other Authors: Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Unité Peste - Plague Unit Antananarivo, Madagascar, Institut Pasteur de Madagascar, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: RAT; FLEA (SYNOPSYLLUS FONQUERNIEI); GENETIQUE DES POPULATIONS; PUCE (SYNOPSYLLUS FONQUERNIEI); [SDV.GEN.GA]Life Sciences [q-bio]/Genetics/Animal genetics; Rattus rattus
• Online Access: https://ird.hal.science/ird-00261411; https://ird.hal.science/ird-00261411/document; https://ird.hal.science/ird-00261411/file/Gilabert_MS5844_final-1.pdf; https://doi.org/10.1139/Z07-083

Correspondance: [e-mail] The genetic structure of reservoir populations is a key characteristic in understanding the persistence of infectious diseases in natural systems. In the Highlands of Madagascar, where plague has persisted since 1920, the black rat, Rattus rattus (L., 1758), is the sole species acting as a reservoir of the disease. Ecological surveys have shown a clear correlation between the locations of the plague-persistence area in Madagascar (above 800 m elevation) and the distribution area of one endemic plague vector, the flea Synopsyllus fonquerniei, which is found exclusively on rats living outdoors. This clear habitat segregation has led to the suggestion that R. rattus populations in the central highlands are divided into indoor- and outdoor-dwelling populations. Using eight microsatellite markers, we analysed the genetic structure of R. rattus populations living within a human plague focus in relation to habitat and geographic distance. We found that habitat by itself was not a structuring factor, unlike geographic distance. Nevertheless, the significant genotypic differentiation of R. rattus populations that was found at a fine spatial scale might relate to differences in population dynamics between rats in indoor and outdoor habitats.