Data from: Genetic rediscovery of an ‘extinct’ Galápagos giant tortoise species

Genes from recently extinct species can live on in the genomes of extant individuals of mixed ancestry. Recently, Poulakakis et al. detected genetic signatures of the giant Galápagos tortoise once endemic to Floreana Island (Chelonoidis elephantopus) within eleven hybrid individuals of otherwise pure C. becki on Volcano Wolf, Isabela Island. Movement of tortoises among islands by pirate and whaling ships was not uncommon during the 1800’s, representing a likely mechanism by which individuals from Floreana were translocated to northern Isabela, despite being presumed extinct soon after Charles Darwin’s historic voyage to the Galápagos Islands in 1835. These eleven hybrid individuals with C. elephantopus ancestry were thought to be the last genetic vestiges of a unique evolutionary lineage in the wild. Here we report that reproductively mature purebred tortoises of the recently ‘extinct’ C. elephantopus from Floreana Island are very likely still alive today, as identified and tracked through the genetic footprints’ left in the genomes of very recent hybrid offspring on Volcano Wolf, Isabela Island. If found, these purebred C. elephantopus individuals could constitute core founders of a captive breeding program directed towards resurrecting this species

Population genetics, community of parasites, and resistance to rodenticides in an urban brown rat (<i>Rattus norvegicus</i>) population

International audienceBrown rats are one of the most widespread urban species worldwide. Despite the nuisances they induce and their potential role as a zoonotic reservoir, knowledge on urban rat populations remains scarce. The main purpose of this study was to characterize an urban brown rat population from Chanteraines park (Hauts-de-Seine, France), with regards to haematology, population genetics, immunogenic diversity, resistance to anticoagulant rodenticides, and community of parasites. Haematological parameters were measured. Population genetics was investigated using 13 unlinked microsatellite loci. Immunogenic diversity was assessed for Mhc-Drb. Frequency of the Y139F mutation (conferring resistance to rodenticides) and two linked microsatellites were studied, concurrently with the presence of anticoagulant residues in the liver. Combination of microscopy and molecular methods were used to investigate the occurrence of 25 parasites. Statistical approaches were used to explore multiple parasite relationships and model parasite occurrence. Eighty-six rats were caught. The first haematological data for a wild urban R. norvegicus population was reported. Genetic results suggested high genetic diversity and connectivity between Chanteraines rats and surrounding population(s). We found a high prevalence (55.8%) of the mutation Y139F and presence of rodenticide residues in 47.7% of the sampled individuals. The parasite species richness was high (16). Seven potential zoonotic pathogens were identified, together with a surprisingly high diversity of Leptospira species (4). Chanteraines rat population is not closed, allowing gene flow and making eradication programs challenging, particularly because rodenticide resistance is highly prevalent. Parasitological results showed that co-infection is more a rule than an exception. Furthermore, the presence of several potential zoonotic pathogens, of which four Leptospira species, in this urban rat population raised its role in the maintenance and spread of these pathogens. Our findings should stimulate future discussions about the development of a long-term rat-control management program in Chanteraines urban park