73 research outputs found

    ATM-Mediated Transcriptional and Developmental Responses to Îł-rays in Arabidopsis

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    ATM (Ataxia Telangiectasia Mutated) is an essential checkpoint kinase that signals DNA double-strand breaks in eukaryotes. Its depletion causes meiotic and somatic defects in Arabidopsis and progressive motor impairment accompanied by several cell deficiencies in patients with ataxia telangiectasia (AT). To obtain a comprehensive view of the ATM pathway in plants, we performed a time-course analysis of seedling responses by combining confocal laser scanning microscopy studies of root development and genome-wide expression profiling of wild-type (WT) and homozygous ATM-deficient mutants challenged with a dose of Îł-rays (IR) that is sublethal for WT plants. Early morphologic defects in meristematic stem cells indicated that AtATM, an Arabidopsis homolog of the human ATM gene, is essential for maintaining the quiescent center and controlling the differentiation of initial cells after exposure to IR. Results of several microarray experiments performed with whole seedlings and roots up to 5 h post-IR were compiled in a single table, which was used to import gene information and extract gene sets. Sequence and function homology searches; import of spatio-temporal, cell cycling, and mutant-constitutive expression characteristics; and a simplified functional classification system were used to identify novel genes in all functional classes. The hundreds of radiomodulated genes identified were not a random collection, but belonged to functional pathways such as those of the cell cycle; cell death and repair; DNA replication, repair, and recombination; and transcription; translation; and signaling, indicating the strong cell reprogramming and double-strand break abrogation functions of ATM checkpoints. Accordingly, genes in all functional classes were either down or up-regulated concomitantly with downregulation of chromatin deacetylases or upregulation of acetylases and methylases, respectively. Determining the early transcriptional indicators of prolonged S-G2 phases that coincided with cell proliferation delay, or an anticipated subsequent auxin increase, accelerated cell differentiation or death, was used to link IR-regulated hallmark functions and tissue phenotypes after IR. The transcription burst was almost exclusively AtATM-dependent or weakly AtATR-dependent, and followed two major trends of expression in atm: (i)-loss or severe attenuation and delay, and (ii)-inverse and/or stochastic, as well as specific, enabling one to distinguish IR/ATM pathway constituents. Our data provide a large resource for studies on the interaction between plant checkpoints of the cell cycle, development, hormone response, and DNA repair functions, because IR-induced transcriptional changes partially overlap with the response to environmental stress. Putative connections of ATM to stem cell maintenance pathways after IR are also discussed

    Multi-isotope analysis of bone collagen of Late Pleistocene ungulates reveals niche partitioning and behavioural plasticity of reindeer during MIS 3

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    Acknowledgements This research was funded by a Leverhulme Research Project Grant (ref: RPG-2017-410 to K.B.), and the Max Planck Institute for Evolutionary Anthropology. A Philip Leverhulme Prize (ref: PLP-2019-284 to K.B.) provided support to K.B. during the production of this manuscript, and M.S. is funded by the NWO Dutch Research council (VICI award VI.C.191.07). We thank C.-H. Bachelier and Jaques Bachelier for facilitating and supporting research at Les Cottés, and the French Ministry of Culture for allowing and funding research at Les Cottés. Thanks to Sven Steinbrenner and Annabell Reiner (MPI-EVA), and Orsolya Czére (Aberdeen) for laboratory assistance, and to Jovita Fawcett and Eléa Gutierrez (Aberdeen) for proof reading and assistance with images.Peer reviewedPublisher PD

    Mouthiers-sur-Boëme, Chez les Rois

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    Chez les Rois est un gisement de référence de l'Aurignacien charentais et un des rares gisements aurignaciens européens à avoir livré des restes humains en place. Fouillé entre 1930 et 1939 par Potut et entre 1948 et 1952 par Mouton et Joffroy (1958), ce gisement a fait l'objet d'un sondage en 2005 et d'une fouille programmée entre 2006 et 2008 (d'Errico et Vanhaeren 2005, 2006, 2007, 2008). Cette opération de terrain a fait suite à la reprise de l'étude des restes humains et du matériel archéologique issus des fouilles Mouton et Joffroy ainsi qu'à sa datation (Ramirez Rozzi et al. sous presse). L'objectif des nouvelles fouilles était de préciser l'attribution culturelle des assemblages, la chronologie et nature de l'occupation aurignacienne ainsi que l'affiliation taxinomique des groupes humains qui ont fréquenté le site

    Neanderthal subsistence at Chez-Pinaud Jonzac (Charente-Maritime, France): A kill site dominated by reindeer remains, but with a horse-laden diet?

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    During the MIS 4 in Southwestern France, Quina Neanderthal from the north of the Aquitaine was characterized by a hunting specialization on the reindeer and the lack of diversity in their diet. They developed task-specific locations dedicated to the capture, the butchery, and the consumption of reindeer, and the whole society seems, in this region, to be dependent on this food resource. In this context, the site of Chez-Pinaud at Jonzac (France) occupies a specific place. First, interpreted as a reindeer kill and butchery site, the recent recovery of the site underlines the importance of the large ungulate (horse and bison) to the faunal spectrum (30% of the NISP). Considering the quantity of meat and grease that these species can provide to hunters, the new zooarchaeological analyses suggest that at least the horse may have played a major role in the diet of the Neanderthal population. Since Jonzac is one of the largest sites for this period, these results relativize the importance of reindeer specialization of the Quina population and the lack of diversityl in their diet

    Widespread anti-sense transcription in apple is correlated with siRNA production and indicates a large potential for transcriptional and/or post-transcriptional control

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    Characterizing the transcriptome of eukaryotic organisms is essential for studying gene regulation and its impact on phenotype. The realization that anti-sense (AS) and noncoding RNA transcription is pervasive in many genomes has emphasized our limited understanding of gene transcription and post-transcriptional regulation. Numerous mechanisms including convergent transcription, anti-correlated expression of sense and AS transcripts, and RNAi remain ill-defined.Here, we have combined microarray analysis and high-throughput sequencing of small RNAs (sRNAs) to unravel the complexity of transcriptional and potential post-transcriptional regulation in eight organs of apple (Malus × domestica). The percentage of AS transcript expression is higher than that identified in annual plants such as rice and Arabidopsis thaliana. Furthermore, we show that a majority of AS transcripts are transcribed beyond 3â€ČUTR regions, and may cover a significant portion of the predicted sense transcripts. Finally we demonstrate at a genome-wide scale that anti-sense transcript expression is correlated with the presence of both short (21–23 nt) and long (> 30 nt) siRNAs, and that the sRNA coverage depth varies with the level of AS transcript expression. Our study provides a new insight on the functional role of anti-sense transcripts at the genome-wide level, and a new basis for the understanding of sRNA biogenesis in plants

    Identifying the unidentified fauna enhances insights into hominin subsistence strategies during the Middle to Upper Palaeolithic transition

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    Understanding Palaeolithic hominin subsistence strategies requires the comprehensive taxonomic identification of faunal remains. The high fragmentation of Late Pleistocene faunal assemblages often prevents proper taxonomic identification based on bone morphology. It has been assumed that the morphologically unidentifiable component of the faunal assemblage would reflect the taxonomic abundances of the morphologically identified portion. In this study, we analyse three faunal datasets covering the Middle to Upper Palaeolithic transition (MUPT) at Bacho Kiro Cave (Bulgaria) and Les Cottés and La Ferrassie (France) with the application of collagen type I peptide mass fingerprinting (ZooMS). Our results emphasise that the fragmented component of Palaeolithic bone assemblages can differ significantly from the morphologically identifiable component. We obtain contrasting identification rates between taxa resulting in an overrepresentation of morphologically identified reindeer (Rangifer tarandus) and an underrepresentation of aurochs/bison (Bos/Bison) and horse/European ass (Equus) at Les Cottés and La Ferrassie. Together with an increase in the relative diversity of the faunal composition, these results have implications for the interpretation of subsistence strategies during a period of possible interaction between Neanderthals and Homo sapiens in Europe. Furthermore, shifts in faunal community composition and in carnivore activity suggest a change in the interaction between humans and carnivores across the MUPT and indicate a possible difference in site use between Neanderthals and Homo sapiens. The combined use of traditional and biomolecular methods allows (zoo)archaeologists to tackle some of the methodological limits commonly faced during the morphological assessment of Palaeolithic bone assemblages

    Sanskrit

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    LĂ©vi Sylvain, Renou Louis. Sanskrit. In: École pratique des hautes Ă©tudes, Section des sciences historiques et philologiques. Annuaire 1932-1933. 1932. pp. 92-94

    Sanskrit

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    LĂ©vi Sylvain, Renou Louis, Lalou Marcelle. Sanskrit. In: École pratique des hautes Ă©tudes, Section des sciences historiques et philologiques. Annuaire 1934-1935. 1934. pp. 61-63

    Sanskrit

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    LĂ©vi Sylvain, Renou Louis, Finot Louis. Sanskrit. In: École pratique des hautes Ă©tudes, Section des sciences historiques et philologiques. Annuaire 1929-1930. 1929. pp. 58-59

    Sanskrit

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    LĂ©vi Sylvain, Renou Louis, Lalou Marcelle. Sanskrit. In: École pratique des hautes Ă©tudes, Section des sciences historiques et philologiques. Annuaire 1934-1935. 1934. pp. 61-63
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