Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has emerged as an active mediator in many essential functions in the central nervous system of mammals. BDNF plays significant roles in neurogenesis, neuronal maturation and/or synaptic plasticity and is involved in cognitive functions such as learning and memory. Despite the vast literature present in mammals, studies devoted to BDNF in the brain of other animal models are scarse. Zebrafish is a teleost fish widely known for developmental genetic studies and is emerging as model for translational neuroscience research. In addition, its brain shows many sites of adult neurogenesis allowing higher regenerative properties after traumatic injuries. To add further knowledge on neurotrophic factors in vertebrate brain models, we decided to determine the distribution of bdnf mRNAs in the larval and adult zebrafish brain and to characterize the phenotype of cells expressing bdnf mRNAs by means of double staining studies. Our results showed that bdnf mRNAs were widely expressed in the brain of 7 days old larvae and throughout the whole brain of mature female and male zebrafish. In adults, bdnf mRNAs were mainly observed in the dorsal telencephalon, preoptic area, dorsal thalamus, posterior tuberculum, hypothalamus, synencephalon, optic tectum and medulla oblongata. By combining immunohistochemistry with in situ hybridization, we showed that bdnf mRNAs were never expressed by radial glial cells or proliferating cells. By contrast, bdnf transcripts were expressed in cells with neuronal phenotype in all brain regions investigated. Our results provide the first demonstration that the brain of zebrafish expresses bdnf mRNAs in neurons and open new fields of research on the role of the BDNF factor in brain mechanisms in normal and brain repairs situations.
ISSN: 1932-6203

hal-01359562
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359562
DOI : 10.1371/journal.pone.0158057
PUBMED : 27336917

Éditeur(s) : HAL CCSD CSIRO Publishing
Résumé : International audience
The present study assessed the occurrence of multiple paternity in four litters of bull shark Carcharhinus leucas (n¼5, 8, 9 and 11 embryos) sampled at Reunion Island in the Western Indian Ocean. Using 21 microsatellite loci, we revealed that two litters were generated from two sires each, demonstrating for the first time multiple paternity for this species. We also reported a high paternal skew (10 : 1 in Litter 1 and 7 : 1 in Litter 3), which may be because of postcopulatory or post-zygotic selection processes. These results contribute to a better understanding of the reproductive behaviour of the bull shark, which remains poorly documented. The present study must be expanded to assess the frequency of multiple paternity in this species, and to test for genetic or cryptic benefits (convenience polyandry), which is important for long-term conservation and management plans.
ISSN: 1323-1650

hal-01253775
https://hal.archives-ouvertes.fr/hal-01253775
https://hal.archives-ouvertes.fr/hal-01253775/document
https://hal.archives-ouvertes.fr/hal-01253775/file/Pirog%20et%20al.%20-%202015%20-%20First%20evidence%20of%20multiple%20paternity%20in%20the%20bull%20s_hal.pdf
DOI : 10.1071/mf15255

Éditeur(s) : HAL CCSD Wiley/Blackwell
Résumé : International audience
Photosynthetic eukaryotes have a critical role as the main producers in most ecosystems of the biosphere. The ongoing environmental metabarcoding revolution opens the perspective for holistic ecosystems biological studies of these organisms, in particular the unicellular microalgae that often lack distinctive morphological characters and have complex life cycles. To interpret environmental sequences, metabarcoding necessarily relies on taxonomically curated databases containing reference sequences of the targeted gene (or barcode) from identified organisms. To date, no such reference framework exists for photosynthetic eukaryotes. In this study, we built the PhytoREF database that contains 6490 plastidial 16S rDNA reference sequences that originate from a large diversity of eukaryotes representing all known major photosynthetic lineages. We compiled 3333 amplicon sequences available from public databases and 879 sequences extracted from plastidial genomes, and generated 411 novel sequences from cultured marine microalgal strains belonging to different eukaryotic lineages. A total of 1867 environmental Sanger 16S rDNA sequences were also included in the database. Stringent quality filtering and a phylogeny-based taxonomic classification were applied for each 16S rDNA sequence. The database mainly focuses on marine microalgae, but sequences from land plants (representing half of the PhytoREF sequences) and freshwater taxa were also included to broaden the applicability of PhytoREF to different aquatic and terrestrial habitats. PhytoREF, accessible via a web interface (http://phytoref.fr), is a new resource in molecular ecology to foster the discovery, assessment and monitoring of the diversity of photosynthetic eukaryotes using high-throughput sequencing.
ISSN: 1755-098X

hal-01149047
http://hal.upmc.fr/hal-01149047
http://hal.upmc.fr/hal-01149047/document
http://hal.upmc.fr/hal-01149047/file/Decelle_2015_PhytoREF.pdf
DOI : 10.1111/1755-0998.12401

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
ISSN: 1471-2148

hal-01683186
https://hal.univ-antilles.fr/hal-01683186
DOI : 10.1186/1471-2148-13-108

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The extensive use of tyrosine kinase inhibitors (TKI's) in hematology and oncology has shown that these drugs have a significant potential for drug-drug interactions. Since these drugs have a rather low therapeutic window, some drug interactions are of particular clinical relevance either on drug toxicity or on patient's response. Significant interactions occur with concomitant use of acid-suppressive therapy leading to a decreased oral bioavailability. However, such interactions are drug dependent according to their solubility pattern and to the duration of action of acid-suppressive therapy, which is coprescribed. Significant interactions occur by inhibition or induction of CYP450 3A4 which is the main metabolic pathway of TKIs. However, minor metabolic pathways should also be paid attention to. Interactions involving efflux and influx transporters should also be considered occurring for some TKIs. Genetic polymorphism in drug metabolism as well as in drug transport is a factor of variability in drug exposure, which could modulate the magnitude of drug-drug interactions (DDIs). It should be noticed that TKIs can also be at the origin of drug interactions by altering the pharmacokinetics of coprescribed drugs. Since cancer patients are given many drugs either for supportive care or for the treatment of drug toxicity, and to the fact that the oldest patients are polymedicated, a clear understanding of DDIs with TKIs is of interest. The objectives of this review are to provide an overview of the mechanisms of DDIs with TKIs and to provide to physicians and pharmacists recommendations to manage these DDIs in their clinical practice.
ISSN: 0278-0232

hal-01616064
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01616064
DOI : 10.1002/hon.2335
PUBMED : 27925256

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Standard microbial evolutionary ontology is organized according to a nested hierarchy of entities at various levels of biological organization. It typically detects and defines these entities in relation to the most stable aspects of evolutionary processes, by identifying lineages evolving by a process of vertical inheritance from an ancestral entity. However, recent advances in microbiology indicate that such an ontology has important limitations. The various dynamics detected within microbiological systems reveal that a focus on the most stable entities (or features of entities) over time inevitably underestimates the extent and nature of microbial diversity. These dynamics are not the outcome of the process of vertical descent alone. Other processes, often involving causal interactions between entities from distinct levels of biological organisation, or operating at different time scales, are responsible not only for the destabilisation of pre-existing entities, but also for the emergence and stabilisation of novel entities in the microbial world. In this article we consider microbial entities as more or less stabilised functional wholes, and sketch a network-based ontology that can represent a diverse set of processes including, for example, as well as phylogenetic relations, interactions that stabilise or destabilise the interacting entities, spatial relations, ecological connections, and genetic exchanges. We use this pluralistic framework for evaluating (i) the existing ontological assumptions in evolution (e.g. whether currently recognized entities are adequate for understanding the causes of change and stabilisation in the microbial world), and (ii) for identifying hidden ontological kinds, essentially invisible from within a more limited perspective. We propose to recognize additional classes of entities that provide new insights into the structure of the microbial world, namely ``processually equivalent'' entities, ``processually versatile'' entities, and ``stabilized'' entities.
ISSN: 0169-3867

hal-01544796
https://hal.archives-ouvertes.fr/hal-01544796
DOI : 10.1007/s10539-012-9350-2