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Murviel-lès-Montpellier, France

Nabholz B.,Montpellier University | Sarah G.,CIRAD - Agricultural Research for Development | Sabot F.,CIRAD - Agricultural Research for Development | Ruiz M.,CIRAD - Agricultural Research for Development | And 6 more authors.
Molecular Ecology | Year: 2014

The African cultivated rice (Oryza glaberrima) was domesticated in West Africa 3000 years ago. Although less cultivated than the Asian rice (O. sativa), O. glaberrima landraces often display interesting adaptation to rustic environment (e.g. drought). Here, using RNA-seq technology, we were able to compare more than 12 000 transcripts between 9 O. glaberrima, 10 wild O. barthii and one O. meridionalis individuals. With a synonymous nucleotide diversity πs = 0.0006 per site, O. glaberrima appears as the least genetically diverse crop grass ever documented. Using approximate Bayesian computation, we estimated that O. glaberrima experienced a severe bottleneck during domestication. This demographic scenario almost fully accounts for the pattern of genetic diversity across O. glaberrima genome as we detected very few outliers regions where positive selection may have further impacted genetic diversity. Moreover, the large excess of derived nonsynonymous substitution that we detected suggests that the O. glaberrima population suffered from the 'cost of domestication'. In addition, we used this genome-scale data set to demonstrate that (i) O. barthii genetic diversity is positively correlated with recombination rate and negatively with gene density, (ii) expression level is negatively correlated with evolutionary constraint, and (iii) one region on chromosome 5 (position 4-6 Mb) exhibits a clear signature of introgression with a yet unidentified Oryza species. This work represents the first genome-wide survey of the African rice genetic diversity and paves the way for further comparison between the African and the Asian rice, notably regarding the genetics underlying domestication traits. © 2014 John Wiley & Sons Ltd. Source

Combes M.-C.,Montpellier University | Dereeper A.,Montpellier University | Severac D.,Institute Of Genomique Fonctionnelle | Bertrand B.,Montpellier University | Lashermes P.,Montpellier University
New Phytologist | Year: 2013

Polyploidy has occurred throughout the evolutionary history of plants and led to diversification and plant ecological adaptation. Functional plasticity of duplicate genes is believed to play a major role in the environmental adaptation of polyploids. In this context, we characterized genome-wide homoeologous gene expression in Coffea arabica, a recent allopolyploid combining two subgenomes that derive from two closely related diploid species, and investigated its variation in response to changing environment. The transcriptome of leaves of C. arabica cultivated at different growing temperatures suitable for one or the other parental species was examined using RNA-sequencing. The relative contribution of homoeologs to gene expression was estimated for 9959 and 10 628 genes in warm and cold conditions, respectively. Whatever the growing conditions, 65% of the genes showed equivalent levels of homoeologous gene expression. In 92% of the genes, relative homoeologous gene expression varied < 10% between growing temperatures. The subgenome contributions to the transcriptome appeared to be only marginally altered by the different conditions (involving intertwined regulations of homeologs) suggesting that C. arabica's ability to tolerate a broader range of growing temperatures than its diploid parents does not result from differential use of homoeologs. © 2013 New Phytologist Trust. Source

Cif L.,Montpellier University Hospital Center | Gonzalez-Martinez V.,Montpellier University Hospital Center | Vasques X.,Montpellier University Hospital Center | Vasques X.,Montpellier University | And 5 more authors.
Journal of Neurosurgery | Year: 2012

Object. Deep brain stimulation (DBS) is used for treating various types of dystonia. Multiple electrodes could be proposed to improve the therapeutic outcome enabling the targeting of specific neuronal populations not reached by the electrical field generated by the initially implanted electrode. The authors address the question of the feasibility and safety of staged multiple lead implantations in the sensorimotor internal globus pallidus (GPi) in primary generalized dystonia (PGD). Criteria for patient selection, surgical technique, target selection, electrical settings management, and clinical outcome are presented. Methods. Sixteen patients (8 harbored the DYT1 gene mutation) presented with PGD and were enrolled in this study. Patients underwent clinical assessment using the Burke-Fahn-Marsden Dystonia Rating Scale preoperatively and during follow-up with DBS. Prior to the addition of electrodes, the authors confirmed, by turning off stimulation, that the patient was still benefiting from DBS and that DBS settings adjustment did not provide further improvement. The second target was defined according to the position of the first electrode, to the residual volume within the sensorimotor GPi, and according to residual symptoms. The second surgery followed the same protocol as the first and the new electrode were inserted using the same bur hole as the first electrode. Results. The addition of a new pair of electrodes was followed by significant improvement in the whole population (p = 0.005), as well as in the DYT1-negative subgroup (p = 0.012) but not in the DYT1 subgroup (p = not significant). Nevertheless, some patients did not exhibit significant additional benefit. Seven hardware-related complications occurred during the entire follow-up, 3 prior to it, and 4 after the addition of the second pair of electrodes. Conclusions. The addition of a second pair of electrodes in the GPi in patients with PGD with suboptimal or decaying benefit following the first surgery seems to be a safe procedure and is not followed by an increase in surgery- related complications. This staged procedure may provide further clinical improvement in patients with PGD in whom DBS effect is initially incomplete or when disease progression occurs over time. The position of the additional electrode within the GPi is determined by the available volume within the posteroventral GPi and by the distribution of the dystonic symptoms that need to be controlled. Source

Bockaert J.,Institute Of Genomique Fonctionnelle
Medecine/Sciences | Year: 2012

The 2012 Nobel Prize for chemistry has been won by Robert J. Lefkowitz and Brian Kobilka for their work on G protein-coupled receptors (GPCRs). Those receptors (3% of human genome) evolutionary are derived from one 1 or 2 ancestors and are able to recognize external message as different as light, odorants, gustative molecules and intercellular messages such as hormones and neurotransmitters. They are targets of 30-40% of therapeutic drugs. Robert J. Lefkowitz has been one of the leaders of the field from more than 40 years and has built several key concepts of the domain. Brian Kobilka was successful, in 2007, in producing a crystal structure of the ?2-adrenergic receptor. This paved the way for the production of a series of almost 50 GPCR crystal structures both in inactive and active forms. Source

Xiao C.,University of Cincinnati | Ogle S.A.,University of Cincinnati | Schumacher M.A.,University of Cincinnati | Orr-Asman M.A.,University of Cincinnati | And 8 more authors.
Gastroenterology | Year: 2010

Background & Aims: Sonic Hedgehog (Shh) is expressed in the adult stomach, but its role as a gastric morphogen is unclear. We sought to identify mechanisms by which Shh might regulate gastric epithelial cell function and differentiation. Methods: Mice with a parietal cell-specific deletion of Shh (HKCre/ShhKO) were created. Gastric morphology and function were studied in control and HKCre/ShhKO mice between 1 and 8 months of age. Results: In contrast to control mice, HKCre/ShhKO mice developed gastric hypochlorhydria, hypergastrinemia, and a phenotype that resembled foveolar hyperplasia. The fundic mucosa of HKCre/ShhKO mice had an expanded surface pit cell lineage that was documented by increased incorporation of bromodeoxyuridine and was attributed to the hypergastrinemia. Compared with controls, numbers of total mucous neck and zymogen cells were significantly decreased in stomachs of HKCre/ShhKO mice. In addition, zymogen and neck cell markers were coexpressed in the same cell populations, indicating disrupted differentiation of the zymogen cell lineage from the mucous neck cells in the stomachs of HKCre/ShhKO mice. Laser capture microdissection of the surface epithelium, followed by quantitative reverse-transcription polymerase chain reaction, revealed a significant increase in expression of Indian Hedgehog, glioma-associated oncogene homolog 1, Wnt, and cyclin D1. Laser capture microdissection analysis also showed a significant increase in Snail with a concomitant decrease in E-cadherin. Conclusions: In the stomachs of adult mice, loss of Shh from parietal cells results in hypochlorhydria and hypergastrinemia. Hypergastrinemia might subsequently induce increased Hedgehog and Wnt signaling in the surface pit epithelium, resulting in hyperproliferation. © 2010 AGA Institute. Source

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