Development of non invasive genetic identification methods for the Pyrenean desman (Galemys pyrenaicus) and first study of its genetic structure in France

Abstract

The Pyrenean desman (Galemys pyrenaicus) is probably one of the most threatened European mammal species. This small insectivorous and semi-aquatic species is endemic to the Pyrenean Mountains and of the north of the Iberic Peninsula. Many biologic aspects of this species are currently suffering from a major lack of information, particularly those concerning its genetics. Therefore the implementation of conservative efforts for the Pyrenean desman remains extremely difficult. In order to improve the knowledge of this vulnerable species and notably, to better understand its distribution area, the first aim of our research was to develop non invasive genetic identification methods based on faeces. The second aim was to have a first look at the phylogeographic structure of the Pyrenean desman. The identification methods were developed on the basis of the sequencing of a small mitochondrial DNA (cyt b) fragment as well as a RFLP method. These approaches led to the identification of the Pyrenean desman and to the differentiation of the latter from two other species living in the same type of habitat, the white-throated dipper (Cinclus cinclus) and the water shrew (Neomys fodiens). Two haplotypes were found in the studied Pyrenean populations but no phylogeographic structure could be established. A dozen of microsatellites markers were also developed during this work and 5 of these were found to be polymorphic. The results of this preliminary work tend to show a low genetic diversity for the Pyrenean desman but this result needs to be confirmed in the future with a more extended and complete study