CNRS Laboratory of Functional Biology, Insects and Interactions

Lyon, France

CNRS Laboratory of Functional Biology, Insects and Interactions

Lyon, France

Time filter

Source Type

Vignon M.,CNRS Host-Pathogen-Environment Interactions Laboratory | Vignon M.,CNRS Insular Research Center and Environment Observatory | Vignon M.,French National Institute for Agricultural Research | Pariselle A.,CNRS Laboratory of Functional Biology, Insects and Interactions | And 2 more authors.
Biological Journal of the Linnean Society | Year: 2011

Cichlidogyrus spp. (Monogenea, Ancyrocephalidae) are common parasites of cichlid fishes from Africa and the Levant. They display important morphological variation in their attachment apparatus and infect a broad host spectrum throughout a wide geographic range. Thus, they offer an interesting model to investigate to what extent the phenotypic variability of the attachment organ among congeners is related to host specificity, geographic/environmental components, or phylogeny. A geometric morphometric approach was carried out to analyse the shape variation of sclerotized structures of the attachment organ within 66 African species of the genus Cichlidogyrus. The interspecific shape comparison supports the presence of three main morphological configurations, each consisting of a given combination of particular sclerite shapes. Moreover, data emphasize strong coordination and integration (shape co-variation) among the different sclerites jointly forming the attachment organ. Although attachment apparatuses are usually considered to be the result of adaptive processes and must be adapted to the hosts and local environmental conditions, we found no relationship between these clusters and host specificity or geographical distribution. Nevertheless, groups are partially congruent with those obtained with the molecular phylogeny of a subset of species, suggesting a phylogenetic constraint rather than an adaptation to either hosts or environment. Because of the necessity to form a functional entity, modularity within attachment organ imposes important evolutionary constraint. This provides new insights into the evolvability of attachment organs, as well as into the morphological basis of host specificity and host-parasite co-evolutionary interaction in helminth parasites. © 2011 The Linnean Society of London.


Jefferson A.,University of Oxford | Jefferson A.,John Radcliffe Hospital | Colella S.,University of Oxford | Colella S.,CNRS Laboratory of Functional Biology, Insects and Interactions | And 6 more authors.
PLoS ONE | Year: 2010

The ICF syndrome is a rare autosomal recessive disorder, the most common symptoms of which are immunodeficiency, facial anomalies and cytogenetic defects involving decondensation and instability of chromosome 1, 9 and 16 centromeric regions. ICF is also characterised by significant hypomethylation of the classical satellite DNA, the major constituent of the juxtacentromeric heterochromatin. Here we report the first attempt at analysing some of the defining genetic and epigenetic changes of this syndrome from a nuclear architecture perspective. In particular, we have compared in ICF (Type 1 and Type 2) and controls the large-scale organisation of chromosome 1 and 16 juxtacentromeric heterochromatic regions, their intra-nuclear positioning, and co-localisation with five specific genes (BTG2, CNN3, ID3, RGS1, F13A1), on which we have concurrently conducted expression and methylation analysis. Our investigations, carried out by a combination of molecular and cytological techniques, demonstrate the existence of specific and quantifiable differences in the genomic and nuclear organisation of the juxtacentromeric heterochromatin in ICF. DNA hypomethylation, previously reported to correlate with the decondensation of centromeric regions in metaphase described in these patients, appears also to correlate with the heterochromatin spatial configuration in interphase. Finally, our findings on the relative positioning of hypomethylated satellite sequences and abnormally expressed genes suggest a connection between disruption of long-range gene-heterochromatin associations and some of the changes in gene expression in ICF. Beyond its relevance to the ICF syndrome, by addressing fundamental principles of chromosome functional organisation within the cell nucleus, this work aims to contribute to the current debate on the epigenetic impact of nuclear architecture in development and disease. © 2010 Jefferson et al.


Beneteau J.,French National Institute for Agricultural Research | Renard D.,French National Institute for Agricultural Research | Marche L.,French National Institute for Agricultural Research | Douville E.,French National Institute for Agricultural Research | And 6 more authors.
Plant Physiology | Year: 2010

Phloem Protein2 (PP2) is a component of the phloem protein bodies found in sieve elements. We describe here the lectin properties of the Arabidopsis (Arabidopsis thaliana) PP2-A1. Using a recombinant protein produced in Escherichia coli, we demonstrated binding to N-acetylglucosamine oligomers. Glycan array screening showed that PP2-A1 also bound to high-mannose N-glycans and 9-acyl-N-acetylneuraminic sialic acid. Fluorescence spectroscopy-based titration experiments revealed that PP2-A1 had two classes of binding site for N,N′,N″-triacetylchitotriose, a low-affinity site and a high-affinity site, promoting the formation of protein dimers. A search for structural similarities revealed that PP2-A1 aligned with the Cbm4 and Cbm22-2 carbohydrate-binding modules, leading to the prediction of a b-strand structure for its conserved domain. We investigated whether PP2-A1 interacted with phloem sap glycoproteins by first characterizing abundant Arabidopsis phloem sap proteins by liquid chromatography-tandem mass spectrometry. Then we demonstrated that PP2-A1 bound to several phloem sap proteins and that this binding was not completely abolished by glycosidase treatment. As many plant lectins have insecticidal activity, we also assessed the effect of PP2-A1 on weight gain and survival in aphids. Unlike other mannose-binding lectins, when added to an artificial diet, recombinant PP2-A1 had no insecticidal properties against Acyrthosiphon pisum and Myzus persicae. However, at mid-range concentrations, the protein affected weight gain in insect nymphs. These results indicate the presence in PP2-A1 of several carbohydrate-binding sites, with potentially different functions in the trafficking of endogenous proteins or in interactions with phloem-feeding insects. © 2010 American Society of Plant Biologists.


Perrin M.,French Institute of Health and Medical Research | Perrin M.,University of Lyon | Henaff M.-A.,French Institute of Health and Medical Research | Henaff M.-A.,University of Lyon | And 6 more authors.
Journal of Alzheimer's Disease | Year: 2012

Healthy subjects remember emotional stimuli better than neutral, as well as stimuli embedded in an emotional context. This better memory of emotional messages is linked to an amygdalo-hippocampal cooperation taking place in a larger fronto-temporal network particularly sensitive to pathological aging. Amygdala is mainly involved in gist memory of emotional messages. Whether emotional content or context enhances memory in mild Alzheimer's disease (AD) patients is still debated. The aim of the present study is to examine the influence of emotional content and emotional context on the memory in mild AD, and whether this influence is linked to amygdala volume. Fifteen patients affected by mild AD and 15 age-matched controls were submitted to series of negative, positive, and neutral pictures. Each series was embedded in an emotional or neutral sound context. At the end of each series, participants had to freely recall pictures, and answer questions about each picture. Amygdala volumes were measured on patient 3D-MRI scans. In the present study, emotional content significantly favored memory of gist but not of details in healthy elderly and in AD patients. Patients' amygdala volume was positively correlated to emotional content memory effect, implying a reduced memory benefit from emotional content when amygdala was atrophied. A positive context enhanced memory of pictures in healthy elderly, but not in AD, corroborating early fronto-temporal dysfunction and early working memory limitation in this disease. © 2012-IOS Press and the authors. All rights reserved.


Hessler I.,University of Bremen | Dupont L.,University of Bremen | Bonnefille R.,Aix - Marseille University | Behling H.,University of Gottingen | And 9 more authors.
Quaternary Science Reviews | Year: 2010

To reconstruct the response of vegetation to abrupt climate changes during the last glacial we have compiled pollen records from the circum-Atlantic tropics between 23°N and 23°S from both marine and terrestrial sediment cores. Pollen data were grouped into mega-biomes to facilitate the comparison between the different records. Most tropical African records do not appear to register Dansgaard-Oeschger (D-O) variability, although there are vegetation changes during Heinrich Stadials (HS). There is a stronger signal of D-O and HS variability in the South American records. Records close to the modern northern and southern limits of the Intertropical Convergence Zone (ITCZ) show opposite trends in vegetation development during HS and D-O cycles. The pollen data from tropical South America corroborate the hypothesis of a southward shift in the migration pattern of the ITCZ and a reduction in the Atlantic Meridional Overturning Circulation (AMOC) during HS. © 2009 Elsevier Ltd.


Nishimura T.D.,Kyoto University | Takai M.,Kyoto University | Senut B.,CNRS Laboratory of Functional Biology, Insects and Interactions | Taru H.,Kanagawa Prefectural Museum of Natural History | And 2 more authors.
Journal of Human Evolution | Year: 2012

In the original description of Dolichopithecus (Kanagawapithecus) leptopostorbitalis, Iwamoto, Hasegawa and Koizumi, 2005, a moderately large-sized colobine monkey from the Late Pliocene of central Japan, affinities to the European Dolichopithecus rather than to the Transbaikalian Parapresbytis were noted based on the similarities in cranial morphology. Computed tomography scans confirm the presence of the maxillary sinus in the holotype, whereas it is probably absent in specimens of the European Dolichopithecus ruscinensis, the type species of this genus. This feature is either present or absent homogeneously in any given genus of living anthropoids. Its presence or absence is unknown in Parapresbytis, but the distinct morphology of the maxillary incisors in this taxon suggests that this form had different feeding habits from the Japanese colobines. These findings suggest that the Japanese colobine should be referred to henceforth as Kanagawapithecus leptopostorbitalis. Kanagawapithecus shares many important facial and dental features with Dolichopithecus rather than with Parapresbytis, but this association depends largely on the limited availability of comparable materials for the latter. Among colobines, the presence of the maxillary sinus is recorded only in Libypithecus and Cercopithecoides. The maxillary sinus is absent in all modern Asian colobines, implying that Kanagawapithecus is an isolated form without any relationship to living forms. Nevertheless, such phylogenetic interpretations are largely dependent on the restricted fossil evidence from the Pliocene and Pleistocene of eastern Eurasia and will be reexamined when new findings are made. © 2012 Elsevier Ltd.


Mendlova M.,Masaryk University | Pariselle A.,CNRS Laboratory of Functional Biology, Insects and Interactions | Vyskocilova M.,Masaryk University | Simkova A.,Masaryk University
Parasitology Research | Year: 2010

The African freshwater fish of Cichlidae are parasitized by five genera of monogeneans belonging to Dactylogyridea. Ectoparasitic Scutogyrus, Onchobdella, and the highly diversified Cichlidogyrus represent three genera located on the gills, while the endoparasitic Enterogyrus and Urogyrus are located in the stomach and the urinary bladder, respectively. Representatives of four dactylogyridean genera (except for Urogyrus) were collected from seven cichlid species in West Africa. The aim of this study was to investigate the phylogenetic relationships between ectoparasitic and endoparasitic dactylogyridaen monogeneans specific to African freshwater Cichlidae and other representatives of Dactylogyridae, including a wide range of species from both freshwater and marine environments. All phylogenetic analyses point to the polyphyletic origin of the subfamily Ancyrocephalinae. Both Enterogyrus and Onchobdella were found to be monophyletic. The phylogenetic position of Scutogyrus longicornis was placed within the Cichlidogyrus species, which suggests the non-monophyly of Cichlidogyrus. Therefore, we have proposed a taxonomical revision of the species recently considered to be Scutogyrus. However, these four dactylogyridean genera-specific to cichlids do not form a monophyletic group. Using LSU rDNA analyses, we found that Enterogyrus and Onchobdella form a clade with Protogyrodactylus, i.e., the parasite species does not live in cichlids, which suggests that endoparasitism in cichlid monogeneans is not an ancestral feature. © 2010 Springer-Verlag.


Penalver E.,Instituto Geologico Y Minero Of Espana | Gaudant J.,CNRS Laboratory of Functional Biology, Insects and Interactions
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

In an attempt to arrive at a preliminary reconstruction of the limnic food web of the Upper Miocene Bicorb Basin (Eastern Spain), and to obtain new palaeontological information regarding the salinity of its palaeolake, studies were made of the fossil assemblages of aquatic organisms in the outcrops of facies associations 2 and 3 (subunit b of the upper unit, established in 1998 by Anadón et al.) These outcrops (known as Venus, Cantera and Bicorb Insectos-1 and -3) are typical Konservat-Lagerstätten. We here describe four specimens of a new species of the cyprinodontid genus Aphanius (A. bicorbensis sp. nov.) plus several chironomid insects and coprolites, mainly from the Venus outcrop. Two morphotypes of chironomid pupal exuviae were found, both of which were attributed to the subfamily Chironominae. The larger morphotype was attributed to Chironomus sp. (tribe Chironomini) and the smaller to Tanytarsini gen. et sp. indet. Coprolites were separated into two types - C1 and C2 - based on their contents, i.e., the remains of chironomids or miliolid foraminifers respectively. The miliolid foraminifers belonged to the family Hauerinidae, possibly to the genus Quinqueloculina. It is concluded that Aphanius fish were second level consumers, feeding on chironomids and miliolid foraminifers. Primary producers were mainly represented by the aquatic plant Potamogeton, Botryococcus green algae, and microbial mats (almost certainly photosynthetic). This notably simple limnic food web and this aquatic fossil assemblage suggest that the Bicorb palaeolake was saline or brackish; the living taxa related to this assemblage are notably tolerant of high salinity. This salinity is related to the presence of a Triassic diapir on the southern side of the Bicorb Basin. In addition, non-bioturbated, finely laminated calcareous mudstones and exceptionally well-preserved delicate insects indicate the lake water to have shown a halocline (leading to meromictic episodes), with the development of microbial mats at the lake bottom. © 2010 Elsevier B.V.


The revision of Prolebias stenoura Sauvage, 1874, the type species of the genus Prolebias Sauvage, 1874, a cyprinodontid fish from the Upper Stampian (= Rupelian) (Oligocene) of the surroundings of Corent (Limagne, central France), has made possible the preparation of a detailed anatomical study and of an emended diagnosis. The occurrence of coccolithophorids and of dinoflagellates has determined several authors to suggest an incursion of marine waters into this basin during the Stampian. However, the fact that all the species of the genus Prolebias hitherto known by articulated skeletons have been living in fresh and brackish waters is, on the contrary, more in agreement with the hypothesis of a shallow meromictic lake, the superficial part of which was filled by seasonal rains, suitable for the life of this species. © Publications Scientifiques du Muséum national d'Histoire naturelle, Paris.


Mone Y.,CNRS Biometry and Evolutionary Biology Laboratory | Mone Y.,CNRS Laboratory of Functional Biology, Insects and Interactions | Monnin D.,CNRS Biometry and Evolutionary Biology Laboratory | Kremer N.,CNRS Biometry and Evolutionary Biology Laboratory | Kremer N.,University of Wisconsin - Madison
Proceedings of the Royal Society B: Biological Sciences | Year: 2014

Symbiotic interactions are ubiquitous in nature and play a major role in driving the evolution of life. Interactions between partners are oftenmediated by shared signalling pathways, which strongly influence both partners' biology and the evolution of the association in various environments. As an example of 'common language', the regulation of the oxidative environment plays an important role in driving the evolution of symbiotic associations. Such processes have been occurring for billions of years, including the increase in Earth's atmospheric oxygen and the subsequent evolution of mitochondria. The effect of reactive oxygen species and reactive nitrogen species (RONS) has been characterized functionally, but the molecular dialogue between partners has not been integrated within a broader evolutionary context yet. Given the pleiotropic role of RONS in cell-cell communication, development and immunity, but also their associatedphysiological costs,we discuss here howtheir regulation can influence the establishment, the maintenance and the breakdown of various symbiotic associations. By synthesizing recent developments in redox biology, we aim to provide an interdisciplinary understanding of the influence of such mediators of interspecies communication on the evolution and stability of symbioses, which in turn can shape ecosystems and play a role in health and disease. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Loading CNRS Laboratory of Functional Biology, Insects and Interactions collaborators
Loading CNRS Laboratory of Functional Biology, Insects and Interactions collaborators