Presence of autism, hyperserotonemia, and severe expressive language impairment in Williams-Beuren syndrome.

International audienceBACKGROUND: Deletion of the Williams-Beuren syndrome (WBS) critical region (WBSCR), at 7q11.23, causes a developmental disorder commonly characterized by hypersociability and excessive talkativeness and often considered the opposite behavioral phenotype to autism. Duplication of the WBSCR leads to severe delay in expressive language. Gene-dosage effects on language development at 7q11.23 have been hypothesized. METHODS: Molecular characterization of the WBSCR was performed by fluorescence in situ hybridization and high-resolution single-nucleotide polymorphism array in two individuals with severe autism enrolled in a genetic study of autism who showed typical WBS facial dysmorphism on systematic clinical genetic examination. The serotonin transporter promoter polymorphism (5-HTTLPR, locus SLC6A4) was genotyped. Platelet serotonin levels and urinary 6-sulfatoxymelatonin excretion were measured. Behavioral and cognitive phenotypes were examined. RESULTS: The two patients had common WBSCR deletions between proximal and medial low copy repeat clusters, met diagnostic criteria for autism and displayed severe impairment in communication, including a total absence of expressive speech. Both patients carried the 5-HTTLPR ss genotype and exhibited platelet hyperserotonemia and low melatonin production. CONCLUSIONS: Our observations indicate that behaviors and neurochemical phenotypes typically associated with autism can occur in patients with common WBSCR deletions. The results raise intriguing questions about phenotypic heterogeneity in WBS and regarding genetic and/or environmental factors interacting with specific genes at 7q11.23 sensitive to dosage alterations that can influence the development of social communication skills. Thus, the influence of WBSCR genes on social communication expression might be dramatically modified by other genes, such as 5-HTTLPR, known to influence the severity of social communication impairments in autism, or by environmental factors, such as hyperserotonemia, given that hyperserotonemia is found in WBS associated with autism but not in WBS without autism. In this regard, WBS provides a potentially fruitful model with which to develop integrated genetic, cognitive, behavioral and neurochemical approaches to study genotype-phenotype correlations, possible gene-environment interactions and genetic background effects. The results underscore the importance of considering careful clinical and molecular genetic examination of individuals diagnosed with autism

Diatom DNA metabarcoding for ecological assessment: Comparison among bioinformatics pipelines used in six European countries reveals the need for standardization

Ecological assessment of lakes and rivers using benthic diatom assemblages currently requires considerable taxonomic expertise to identify species using light microscopy. This traditional approach is also time-consuming. Diatom metabarcoding is a promising alternative and there is increasing interest in using this approach for routine assessment. However, until now, analysis protocols for diatom metabarcoding have been developed and optimised by research groups working in isolation. The diversity of existing bioinformatics methods highlights the need for an assessment of the performance and comparability of results of different methods. The aim of this study was to test the correspondence of outputs from six bioinformatics pipelines currently in use for diatom metabarcoding in different European countries. Raw sequence data from 29 biofilm samples were treated by each of the bioinformatics pipelines, five of them using the same curated reference database. The outputs of the pipelines were compared in terms of sequence unit assemblages, taxonomic assignment, biotic index score and ecological assessment outcomes. The three last components were also compared to outputs from traditional light microscopy, which is currently accepted for ecological assessment of phytobenthos, as required by the Water Framework Directive. We also tested the performance of the pipelines on the two DNA markers (rbcL and 185-V4) that are currently used by the working groups participating in this study. The sequence unit assemblages produced by different pipelines showed significant differences in terms of assigned and unassigned read numbers and sequence unit numbers. When comparing the taxonomic assignments at genus and species level, correspondence of the taxonomic assemblages between pipelines was weak. Most discrepancies were linked to differential detection or quantification of taxa, despite the use of the same reference database. Subsequent calculation of biotic index scores also showed significant differences between approaches, which were reflected in the final ecological assessment. Use of the rbcL marker always resulted in better correlation among molecular datasets and also in results closer to these generated using traditional microscopy. This study shows that decisions made in pipeline design have implications for the dataset's structure and the taxonomic assemblage, which in turn may affect biotic index calculation and ecological assessment. There is a need to define best-practice bioinformatics parameters in order to ensure the best representation of diatom assemblages. Only the use of similar parameters will ensure the compatibility of data from different working groups. The future of diatom metabarcoding for ecological assessment may also lie in the development of new metrics using, for example, presence/absence instead of relative abundance data. (C) 2020 The Authors. Published by Elsevier B.V

La transparence dans les systemes distribues : l'approche de GOTHIC

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

La transparence dans les systemes distribues: l'approche de GOTHIX

SIGLEINIST T 71661 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Nouvelle Stratégie de Protection des Cultures Vivrières Contre la Fourmi Attine Acromyrmex octospinosus (Reich) en Guadeloupe : les plantes résistantes à la défoliation

Acromyrmex octospinosus is the only Attine species present in Guadeloupe. It is an important phytophagous pest of food crops. In prospect of a selection of resistant cultivars, we have undertaken the study of some Dioscoreaceae forsaken by the leaf cutting ant during the selection of plant material to cut out. Biochemical and ethological investigations arc undertaken to determine the causes of this Attine inapperence to these plants. This natural resistance is of chemical kind and the cansing marcers are extractible with methanol. The preliminary analysis in thin layer chromatography allows linking them up 10 the saponin group. This point seems to be confirmed by the saponin quantitative analysis in the five studied Dioscoreaceae species

Invasion of Tomato Roots and Reproduction of Meloidogyne incognita as Affected by Raw Sewage Sludge

The antagonistic effects of raw sewage sludge on infection of tomato by Meloidogyne incognita were tested in greenhouse pot experiments. Sludge was mixed with the soil or added on its surface before and after inoculation of tomato plants with nematode eggs. Juvenile penetration was determined 1 and 10 days after inoculation, and 6 weeks later root systems were assessed for nematode reproduction. Fewer juveniles penetrated roots in pots with sludge added to the soil than in unamended control pots. In both experiments, roots were severely galled despite a significant reduction in gall ratings in amended relative to unamended soils. Egg production in treated soil was less (P = 0.05) than in control pots, regardless of whether sludge was incorporated or added 1 day before or after inoculation. In treated pots, RF values (final egg number/inoculation egg number) were strongly reduced. The toxic effects observed on the parasite may result from the ammoniacal nitrogen released in the soil within 7 days after treatment, associated with possible poor host suitability of tomatoes grown in amended substrate and short-lasting compound(s) active after root invasion

Essais de parasitisme de Neoaplectana carpocapsae (Nematoda - Rhabditida) sur la fourmi-manioc : Acromyrmex octospinosus Reich (Formicidae, Attini)

L'action parasitaire de Neoaplectana carpocapsae sur la fourmi-manioc de Guadeloupe Acromyrmex octospinosus, décroît en fonction de l'âge de l'hôte. La pénétration et le développement du nématode sont analysés selon les stades du couvain jusqu'à l'imago. La mortalité des ouvrières adultes est nettement accrue en présence des stades infestants du nématode qui restent toutefois concentrés dans la poche infra-buccale. L'inoculation massive d'un nid artificiel montre l'existence de mécanismes permettant l'élimination des nématodes injectés dans le champignon

Analyse par digitalisation d'images du comportement d'affouragement d'une fourmi attine : application aux tests de choix

Nous décrivons l’automatisation de l’enregistrement et de l’analyse du comportement d’affouragement d’une fourmi attine Acromyrmex octospinosus (Reich) en vue de diverses applications à des tests de préférence. Le montage est réalisé à l’aide d’un micro-ordinateur couplé à une caméra électronique. Le comportement analysé est la prise de confetti (de limbe de différentes espèces végétales ou de papier filtre imbibé d’extraits à éprouver) déposés au hasard sur une grille de choix. Les avantages et les limites de cette méthode sont discutés.A new method is described for the automatic recording and analysis of foraging behaviour in the leaf-cutting ant Acromyrmex octospinosus (Reich). This method had various applications in relation to preference tests. The setup involved a micro-computer linked to a video camera. The behaviour analysed was selection of "confetti" (leaf-discs cut from various plant species or filter-paper discs treated with extracts to be tested) placed randomly on a grid. The advantages and limitations of this method are discussed