72 research outputs found
AMMA information system: an efficient cross-disciplinary tool and a legacy for forthcoming projects
International audienceIn the framework of the African Monsoon Multidisciplinary Analyses (AMMA) programme, several tools have been developed in order to facilitate and speed up data and information exchange between researchers from different disciplines. The AMMA information system includes a multidisciplinary user-friendly distributed data management and distribution system, a reports and quick looks archive associated with a display website and scientific papers exchange systems. All the applications have been developed by several French institutions and fully duplicated in Niamey, Niger
Novel Insights into the Bovine Polled Phenotype and Horn Ontogenesis in Bovidae
Despite massive research efforts, the molecular etiology of bovine polledness and the developmental pathways involved in horn ontogenesis are still poorly understood. In a recent article, we provided evidence for the existence of at least two different alleles at the Polled locus and identified candidate mutations for each of them. None of these mutations was located in known coding or regulatory regions, thus adding to the complexity of understanding the molecular basis of polledness. We confirm previous results here and exhaustively identify the causative mutation for the Celtic allele (PC) and four candidate mutations for the Friesian allele (PF). We describe a previously unreported eyelash-and-eyelid phenotype associated with regular polledness, and present unique histological and gene expression data on bovine horn bud differentiation in fetuses affected by three different horn defect syndromes, as well as in wild-type controls. We propose the ectopic expression of a lincRNA in PC/p horn buds as a probable cause of horn bud agenesis. In addition, we provide evidence for an involvement of OLIG2, FOXL2 and RXFP2 in horn bud differentiation, and draw a first link between bovine, ovine and caprine Polled loci. Our results represent a first and important step in understanding the genetic pathways and key process involved in horn bud differentiation in Bovidae
HyMeX: A 10-Year Multidisciplinary Program on the Mediterranean Water Cycle
Drobinski, P. ... et. al.-- 20 pages, 10 figures, 1 table, supplement material http://journals.ametsoc.org/doi/suppl/10.1175/BAMS-D-12-00244.1HyMeX strives to improve our understanding of the Mediterranean water cycle, its variability from the weather-scale events to the seasonal and interannual scales, and its characteristics over one decade (2010–20), with a special focus on hydrometeorological extremes and the associated social and economic vulnerability of the Mediterranean territoriesHyMeX was developed by an international group of scientists and is currently funded by a large number of agencies. It has been the beneficiary of financial contributions from CNRS; Météo-France; CNES; IRSTEA; INRA; ANR; Collectivité Territoriale de Corse; KIT; CNR; Université de Toulouse; Grenoble Universités; EUMETSAT; EUMETNET; AEMet; Université Blaise Pascal, Clermont Ferrand; Université de la Méditerranée (Aix-Marseille II); Université Montpellier 2; CETEMPS; Italian Civil Protection Department; Université Paris- Sud 11; IGN; EPFL; NASA; New Mexico Tech; IFSTTAR; Mercator Ocean; NOAA; ENEA; TU Delft; CEA; ONERA; IMEDEA; SOCIB; ETH; MeteoCat; Consorzio LAMMA; IRD; National Observatory of Athens; Ministerio de Ciencia e Innovación; CIMA; BRGM; Wageningen University and Research Center; Department of Geophysics, University of Zagreb; Institute of Oceanography and Fisheries, Split, Croatia; INGV; OGS; Maroc Météo; DHMZ; ARPA Piemonte; ARPA-SIMC Emilia-Romagna; ARPA Calabria; ARPA Friuli Venezia Giulia; ARPA Liguria; ISPRA; University of Connecticut; Università degli Studi dell'Aquila; Università di Bologna; Università degli Studi di Torino; Università degli Studi della Basilicata; Università La Sapienza di Roma; Università degli Studi di Padova; Università del Salento; Universitat de Barcelona; Universitat de les Illes Balears; Universidad de Castilla-La Mancha; Universidad Complutense de Madrid; MeteoSwiss; and DLR. It also received support from the European Community's Seventh Framework Programme (e.g., PERSEUS, CLIM-RUN)Peer reviewe
The BLLAST field experiment: Boundary-Layer late afternoon and sunset turbulence
Due to the major role of the sun in heating the earth's surface, the atmospheric planetary boundary layer over land is inherently marked by a diurnal cycle. The afternoon transition, the period of the day that connects the daytime dry convective boundary layer to the night-time stable boundary layer, still has a number of unanswered scientific questions. This phase of the diurnal cycle is challenging from both modelling and observational perspectives: it is transitory, most of the forcings are small or null and the turbulence regime changes from fully convective, close to homogeneous and isotropic, toward a more heterogeneous and intermittent state. These issues motivated the BLLAST (Boundary-Layer Late Afternoon and Sunset Turbulence) field campaign that was conducted from 14 June to 8 July 2011 in southern France, in an area of complex and heterogeneous terrain. A wide range of instrumented platforms including full-size aircraft, remotely piloted aircraft systems, remote-sensing instruments, radiosoundings, tethered balloons, surface flux stations and various meteorological towers were deployed over different surface types. The boundary layer, from the earth's surface to the free troposphere, was probed during the entire day, with a focus and intense observation periods that were conducted from midday until sunset. The BLLAST field campaign also provided an opportunity to test innovative measurement systems, such as new miniaturized sensors, and a new technique for frequent radiosoundings of the low troposphere. Twelve fair weather days displaying various meteorological conditions were extensively documented during the field experiment. The boundary-layer growth varied from one day to another depending on many contributions including stability, advection, subsidence, the state of the previous day's residual layer, as well as local, meso- or synoptic scale conditions. Ground-based measurements combined with tethered-balloon and airborne observations captured the turbulence decay from the surface throughout the whole boundary layer and documented the evolution of the turbulence characteristic length scales during the transition period. Closely integrated with the field experiment, numerical studies are now underway with a complete hierarchy of models to support the data interpretation and improve the model representations.publishedVersio
A multi-scale analysis of bull sperm methylome revealed both species peculiarities and conserved tissue-specific
peer-reviewedBackground: Spermatozoa have a remarkable epigenome in line with their degree of specialization, their unique
nature and different requirements for successful fertilization. Accordingly, perturbations in the establishment of DNA
methylation patterns during male germ cell differentiation have been associated with infertility in several species.Background: Spermatozoa have a remarkable epigenResults: The quantification of DNA methylation at CCGG sites using luminometric methylation assay (LUMA)
highlighted the undermethylation of bull sperm compared to the sperm of rams, stallions, mice, goats and men.
Total blood cells displayed a similarly high level of methylation in bulls and rams, suggesting that undermethylation
of the bovine genome was specific to sperm. Annotation of CCGG sites in different species revealed no striking bias
in the distribution of genome features targeted by LUMA that could explain undermethylation of bull sperm. To
map DNA methylation at a genome-wide scale, bull sperm was compared with bovine liver, fibroblasts and
monocytes using reduced representation bisulfite sequencing (RRBS) and immunoprecipitation of methylated DNA
followed by microarray hybridization (MeDIP-chip). These two methods exhibited differences in terms of genome
coverage, and consistently, two independent sets of sequences differentially methylated in sperm and somatic cells
were identified for RRBS and MeDIP-chip. Remarkably, in the two sets most of the differentially methylated
sequences were hypomethylated in sperm. In agreement with previous studies in other species, the sequences that
were specifically hypomethylated in bull sperm targeted processes relevant to the germline differentiation program
(piRNA metabolism, meiosis, spermatogenesis) and sperm functions (cell adhesion, fertilization), as well as satellites
and rDNA repeats.
Conclusions: These results highlight the undermethylation of bull spermatozoa when compared with both bovine
somatic cells and the sperm of other mammals, and raise questions regarding the dynamics of DNA methylation in
bovine male germline. Whether sperm undermethylation has potential interactions with structural variation in the
cattle genome may deserve further attention.
While bull semen is widely used in artificial insemination, the literature describing DNA methylation in bull
spermatozoa is still scarce. The purpose of this study was therefore to characterize the bull sperm methylome
relative to both bovine somatic cells and the sperm of other mammals through a multiscale analysis
Eclairages apportés par l'identification moléculaire des gènes de coloration chez le poulet sur le mode d'action des mutations, l'homologie de locus entre espèces et la domestication
National audienc
Complete association between a retroviral insertion in the tyrosinase gene and the recessive white mutation in chickens
<p>Abstract</p> <p>Background</p> <p>In chickens, three mutant alleles have been reported at the <it>C </it>locus, including the albino mutation, and the recessive white mutation, which is characterized by white plumage and pigmented eyes. The albino mutation was found to be a 6 bp deletion in the tyrosinase (<it>TYR</it>) gene. The present work describes an approach to identify the structural rearrangement in the <it>TYR </it>gene associated with the recessive white mutation.</p> <p>Results</p> <p>Molecular analysis of the chicken <it>TYR </it>gene has revealed a major structural difference (Restriction Fragment Length Polymorphism, RFLP) in the genomic DNA of the recessive white chicken. A major size difference of 7.7 kb was found in intron 4 of the <it>TYR </it>gene by long-range PCR. Molecular cloning and sequencing results showed the insertion of a complete avian retroviral sequence of the Avian Leukosis Virus (<it>ALV</it>) family. Several aberrant transcripts of the tyrosinase gene were found in 10 week old recessive white chickens but not in the homozygous wild type colored chicken. We established a rapid genotyping diagnostic test based on the discovery of this retroviral insertion. It shows that all homozygous carriers of this insertion had a white plumage in various chicken strains. Furthermore, it was possible to distinguish heterozygous carriers from homozygous normal chickens in a segregating line.</p> <p>Conclusion</p> <p>In this study, we conclude that the insertion of a complete avian retroviral sequence in intron 4 of the tyrosinase gene is diagnostic of the recessive white mutation in chickens. This insertion causes aberrant transcripts lacking exon 5, and we propose that this insertion is the causal mutation for the recessive white allele in the chicken.</p
Genome-wide transcriptomic analysis of liver in sex-linked dwarf and wild-type chickens
Genome-wide transcriptomic analysis of liver in sex-linked dwarf and wild-type chickens. 35. International Society for Animal Genetics Conferenc
La lignée " Leghorn double jaune" : un modèle d'étude du déterminisme génétique du taux d'ovulation chez la poule
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A retrovirus insertion causes abnormal expression of the tyrosinase gene in recessive white chickens
Chantier qualité spécifique "Auteurs Externes" département de Génétique animale : uniquement liaison auteur au référentiel HR-Accessabsen
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