Historical biogeography of the land snail Cornu aspersum: new insights into the scenario inferred from haplotype distribution in both Europe and North Africa.

International audienceBackground: Despite its key location between the rest of the continent and Europe, research on the phylogeography of north African species remains very limited compared to European and North American taxa. The Mediterranean land mollusc Cornu aspersum (= Helix aspersa) is part of the few species widely sampled in north Africa for biogeographical analysis. It then provides an excellent biological model to understand phylogeographical patterns across the Mediterranean basin, and to evaluate hypotheses of population differentiation. We investigated here the phylogeography of this land snail to reassess the evolutionary scenario we previously considered for explaining its scattered distribution in the western Mediterranean, and to help to resolve the question of the direction of its range expansion (from north Africa to Europe or vice versa). By analysing simultaneously individuals from 73 sites sampled in its putative native range, the present work provides the first broad-scale screening of mitochondrial variation (cyt b and 16S rRNA genes) of C. aspersum. Results: Phylogeographical structure mirrored previous patterns inferred from anatomy and nuclear data, since all haplotypes could be ascribed to a B (West) or a C (East) lineage. Alternative migration models tested confirmed that C. aspersum most likely spread from north Africa to Europe. In addition to Kabylia in Algeria, which would have been successively a centre of dispersal and a zone of secondary contacts, we identified an area in Galicia where genetically distinct west and east type populations would have regained contact. Conclusions: Vicariant and dispersal processes are reviewed and discussed in the light of signatures left in the geographical distribution of the genetic variation. In referring to Mediterranean taxa which show similar phylogeographical patterns, we proposed a parsimonious scenario to account for the "east-west" genetic splitting and the northward expansion of the western (B) clade which roughly involves (i) the dispersal of ancestral (eastern) types through Oligocene terranes in the Western Mediterranean (ii) the Tell Atlas orogenesis as gene flow barrier between future west and east populations, (iii) the impact of recurrent climatic fluctuations from mid-Pliocene to the last ice age, (iv) the loss of the eastern lineage during Pleistocene northwards expansion phases

Phylogeography and historical demography of the Lusitanian snail Elona quimperiana reveal survival in unexpected separate glacial refugia

<p>Abstract</p> <p>Background</p> <p>Present day distributions of Palearctic taxa in northern latitudes mainly result from populations having survived in local patches during the Late Pleistocene and/or from recolonizing populations from southern temperate refugia. If well-studied Mediterranean and eastern European refugia are widely accepted, some recent biogeographical assumptions still remain unclear, such as the occurrence of multiple glacial refugia in Iberia and cryptic refugia in northern Europe during the last glaciations. The Lusitanian snail <it>Elona quimperiana </it>has a remarkably disjunct distribution, limited to northwestern France (Brittany), northwestern Spain and the Basque Country. By describing the phylogeographical structure of this species across its entire range, the present study attempts to identify refugia and subsequent recolonization routes.</p> <p>Results</p> <p>Results based on 16S and COI gene sequences showed that the low genetic diversity observed in the Brittany populations should be associated with a recent demographic expansion. By contrast, populations from Spain exhibit several differentiated lineages and are characterized by demographic equilibrium, while the Basque populations are the only ones harboring typical distinct haplotypes. The center of the star-like networks of both gene sequences is occupied by a common ancestral-like haplotype found in Brittany and Spain, which might have originated from the middle of Northern Spain (i.e. Asturias, eastern Lugo and western Cantabria). Estimates of the divergence time between the Spain-Brittany and Basque lineages strongly suggest that <it>E. quimperiana </it>survived the Pleistocene glaciations in distinct refugia on the Iberian Peninsula, one of which is situated in Picos de Europa, and the other in the Basque Country. The occurrence of a northern refugium in France cannot be rejected as of yet.</p> <p>Conclusion</p> <p>Present results confirm the Iberian origin of the land snail <it>E. quimperian</it>a and strongly support the emerging phylogeographic hypothesis of multiple refugia in Iberia during the last glaciations. The scenario of a spatial expansion of <it>E. quimperiana </it>from an Iberian refuge located in Asturias to northern areas provides the most probable explanation for the present distribution of this land snail. By harboring distinct haplotypes, the Basque Country populations appear to be of great importance in terms of potential adaptation, long term persistence and hence, the conservation of <it>E. quimperiana</it>.</p

Amoebose-infestation et amoebose-maladie (généralités, espoir thérapeutiques en 2011 et impact pharmaco-économique mondial)

RENNES1-BU Santé (352382103) / SudocSudocFranceF

Les moustiques (de la protection individuelle à la lutte anti-vectorielle)

RENNES1-BU Santé (352382103) / SudocSudocFranceF

Gènes impliqués dans l'immunité des mollusques terrestres (caractérisation et quantification des dermatopontines)

RENNES1-BU Santé (352382103) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Gènes impliqués dans l'immunité des mollusques terrestres (caractérisation et quantification des dermatopontines)

RENNES1-BU Santé (352382103) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Spinturnicid mites and bats cophylogeny: Comment on Bruyndonckx et al. (2009) 'Molecular cophylogenetic relationships between European bats and their ectoparasitic mites (Acari, Spinturnicidae)'.

Letter to the EditorInternational audienceRecently, Bruyndonckx et al. (2009) used phylogenetic analyses of mitochondrial sequences of European Spinturnicidae parasitizing bats to assess the coevolutionary relationships between host and parasite lineages. Despite being a good investigation into bat ecology and exhibiting an indisputable competence in molecular data analysis, the paper reflects a lack of knowledge of the basic biology and ecology of Spinturnicidae. This shortcoming arises from the fact that the authors do not appropriately review earlier important studies, so that they reach dubious conclusions. Here we comment on their findings and suggest references related to their hypotheses

Prise en charge des parasitoses de l'enfant à l'officine (poux, tiques, gale, vers)

Les ectoparasitoses sont des dermatoses parasitaires ubiquitaires et contagieuses représentées essentiellement par la pédiculose du cuir chevelu et la gale. Elles constituent un véritable enjeu de santé publique au vu de leur importance prévalence dans les collectivités et des problèmes thérapeutiques. Le développement de nouveaux agents antiparasitaires et l'émergence de résistances aux insecticides imposent la réévaluation des stratégies de prise en charge de ces ectoparasitoses. La méningo-encéphalite à tiques est une maladie virale transmise à l'homme par morsure de tiques. Elle fait partie des arboviroses (arthropod-borne viruses). Il n'existe pas de traitement spécifique. La vaccination représente la mesure préventive essentielle. Du fait de leur méconnaissance de l'hygiène alimentaire, les enfants sont souvent infestés par les parasites intestinaux. Les traitements actuels sont efficaces, bien tolérés, et d'administration facileThe ectoparasites are ubiquitous and contagious parasitic skin diseases, mainly represented by head lice and scabies. Regarding to their high prevalence in the community and therapeutic problems, they from a real public health issue. Considering the development of new antiparasitic agents and the emergence of resistance to insecticides, an ectoparasites support strategies reassessment is needed. Meningoencephalitis is a viral disease transmitted to human race through the bite of ticks. It is part of arboviruses (arthropod-borne viruses). There is no specific treatment. Vaccination is the major preventive measure. Because of their lack of food hygiene, children are often infected with intestinal parasites. Current treatments are effective, well tolerated and easily administered.RENNES1-BU Santé (352382103) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

COMPARAISON DES PHYLOGENIES MOLECULAIRES DE QUELQUES ESPECES DE MOLLUSQUES TERRESTRES ET DE LEURS NEMATODES PARASITES (RESULTATS PRELIMINAIRES)

RENNES1-BU Santé (352382103) / SudocSudocFranceF

Pressions évolutives et stratégies d'invasion

International audienc