Island colonization and founder effects: the invasion of the Guadeloupe islands by ship rats (Rattus rattus)

• Published in: Molecular Ecology
• Main Authors: Abdelkrim, Jawad, Pascal, Michel, Samadi, Sarah
• Other Authors: Station commune de Recherches en Ichtyophysiologie, Biodiversité et Environnement (SCRIBE), Institut National de la Recherche Agronomique (INRA), Evolution Paris Seine, Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD Réunion ), Muséum national d'Histoire naturelle (MNHN), Université Pierre et Marie Curie - Paris 6 (UPMC), Systématique, adaptation, évolution (SAE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: BIOLOGICAL INVASION; BOTTLENECK; ERADICATION MANAGEMENT; FOUNDER EFFECT; ISLAND; INVASION BIOLOGIQUE; GENETIQUE DES POPULATIONS; [SDV.BBM]Life Sciences [q-bio]/Biochemistry; Molecular Biology; Rattus rattus
• Online Access: https://hal.inrae.fr/hal-02678563; https://doi.org/10.1111/j.1365-294X.2005.02604.x

International audience The stepwise colonization of islands within an archipelago is typically punctuated by successive founder effects, with each newly founded population being a subsample of the gene pool of the source island. Thus, the genetic signature of successive bottlenecks should be detected when analysing the genetic structure between islands of an archipelago. To test this prediction, we investigated introduced ship rat populations, Rattus rattus (Linnaeus, 1758), in the Guadeloupe Archipelago. Three different methods, commonly named the heterozygosity excess, the mode-shift indicator and the M ratio method, were used to detect bottlenecks from genetic data obtained with eight microsatellite markers on Guadeloupe and two neighbouring islands, Petite-Terre and Fajou. Moreover, a recent eradication failure on Fajou allowed us to test the accuracy of the methods in an ‘experimental-like’ situation. The results indicate that rats were introduced on Guadeloupe first, which then became the source population for independent secondary colonization of Fajou and Petite-Terre. Moreover, the heterozygosity excess and the mode-shift indicator only detected bottlenecks for the recent colonization of Petite-Terre and the eradication failure on Fajou. However, bottlenecks were detected for all the populations using the M ratio method. This could be interpreted as the remaining signature of the early introduction of the ship rat in the archipelago.