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391.
BACKGROUNDS AND AIMS: Nitrogen nutrition of legumes, which relies both on atmospheric N2 and soil mineral N, remains a major limiting factor of growth. A decade ago, breeders tried to increase N uptake through hypernodulation. Despite their high nodule biomass, hypernodulating mutants were never shown to accumulate more nitrogen than wild types; they even generally displayed depressed shoot growth. The aim of this study was to dissect genetic variability associated with N nutrition in relation to C nutrition, using an ecophysiological framework and to propose an ideotype for N nutrition in pea. METHODS: Five pea genotypes (Pisum sativum) characterized by contrasting root and nodule biomasses were grown in the field. Variability among genotypes in dry matter and N accumulation was analysed, considering both the structures involved in N acquisition in terms of root and nodule biomass and their efficiency, in terms of N accumulated through mineral N absorption or symbiotic N2 fixation per amount of root or nodule biomass, respectively. KEY RESULTS: Nodule efficiency of hypernodulating mutants was negatively correlated to nodule biomass, presumably due to the high carbon costs induced by their excessive nodule formation. Root efficiency was only negatively correlated to root biomass before the beginning of the seed-filling stage, suggesting competition for carbon between root formation and functioning during the early stages of growth. This was no longer the case after the beginning of the seed-filling stage and nitrate absorption was then positively correlated to root biomass. CONCLUSIONS: Due to the high C costs induced by nodule formation and its detrimental effect on shoot and root growth, selecting traits for the improvement of N acquisition by legumes must be engineered (a) considering inter-relationships between C and N metabolisms and (b) in terms of temporal complementarities between N2 fixation and nitrate absorption rather than through direct increase of nodule and/or root biomass. 相似文献
392.
Léa Cabrol Luc Malhautier Franck Poly Anne-Sophie Lepeuple Jean-Louis Fanlo 《Applied microbiology and biotechnology》2010,85(3):779-790
In this study, we explored methodological aspects of nucleic acid recovery from microbial communities involved in a gas biofilter
filled with pine bark woodchips. DNA was recovered indirectly in two steps, comparing different methods: cell dispersion (crushing,
shaking, and sonication) and DNA extraction (three commercial kits and a laboratory protocol). The objectives were (a) to
optimize cell desorption from the packing material and (b) to compare the 12 combinations of desorption and extraction methods,
according to three relevant criteria: DNA yield, DNA purity, and community structure representation by denaturing gradient
gel electrophoresis (DGGE). Cell dispersion was not influenced by the operational parameters tested for shaking and blending,
while it increased with time for sonication. DNA extraction by the laboratory protocol provided the highest DNA yields, whereas
the best DNA purity was obtained by a commercial kit designed for DNA extraction from soil. After successful PCR amplification,
the 12 methods did not generate the same bias in microbial community representation. Eight combinations led to high diversity
estimation, independently of the experimental procedure. Among them, six provided highly similar DGGE profiles. Two protocols
generated a significantly dissimilar community profile, with less diversity. This study highlighted the crucial importance
of DNA recovery bias evaluation. 相似文献
393.
CARD15/NOD2 mutational analysis and genotype-phenotype correlation in 612 patients with inflammatory bowel disease 总被引:32,自引:0,他引:32 下载免费PDF全文
Lesage S Zouali H Cézard JP Colombel JF Belaiche J Almer S Tysk C O'Morain C Gassull M Binder V Finkel Y Modigliani R Gower-Rousseau C Macry J Merlin F Chamaillard M Jannot AS Thomas G Hugot JP;EPWG-IBD Group;EPIMAD Group;GETAID Group 《American journal of human genetics》2002,70(4):845-857
CARD15/NOD2 encodes a protein involved in bacterial recognition by monocytes. Mutations in CARD15 have recently been found in patients with Crohn disease (CD), a chronic inflammatory condition of the digestive tract. Here, we report the mutational analyses of CARD15 in 453 patients with CD, including 166 sporadic and 287 familial cases, 159 patients with ulcerative colitis (UC), and 103 healthy control subjects. Of 67 sequence variations identified, 9 had an allele frequency >5% in patients with CD. Six of them were considered to be polymorphisms, and three (R702W, G908R, and 1007fs) were confirmed to be independently associated with susceptibility to CD. Also considered as potential disease-causing mutations (DCMs) were 27 rare additional mutations. The three main variants (R702W, G908R, and 1007fs) represented 32%, 18%, and 31%, respectively, of the total CD mutations, whereas the total of the 27 rare mutations represented 19% of DCMs. Altogether, 93% of the mutations were located in the distal third of the gene. No mutations were found to be associated with UC. In contrast, 50% of patients with CD carried at least one DCM, including 17% who had a double mutation. This observation confirmed the gene-dosage effect in CD. The patients with double-dose mutations were characterized by a younger age at onset (16.9 years vs. 19.8 years; P=.01), a more frequent stricturing phenotype (53% vs. 28%; P=.00003; odds ratio 2.92), and a less frequent colonic involvement (43% vs. 62%; P=.003; odds ratio 0.44) than were seen in those patients who had no mutation. The severity of the disease and extraintestinal manifestations were not different for any of the CARD15 genotypes. The proportion of familial and sporadic cases and the proportion of patients with smoking habits were similar in the groups of patients with CD with or without mutation. These findings provide tools for a DNA-based test of susceptibility and for genetic counseling in inflammatory bowel disease. 相似文献
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Pedro Gonzalez-Menendez Manuela Romano Hongxia Yan Ruhi Deshmukh Julien Papoin Leal Oburoglu Marie Daumur Anne-Sophie Dumé Ira Phadke Cédric Mongellaz Xiaoli Qu Phuong-Nhi Bories Michaela Fontenay Xiuli An Valérie Dardalhon Marc Sitbon Valérie S. Zimmermann Patrick G. Gallagher Sandrina Kinet 《Cell reports》2021,34(5):108723
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399.
Sabira Hachem Anne-Sophie Laurenson Jean-Philippe Hugnot Catherine Legraverend 《BMC developmental biology》2007,7(1):17
Background
In the cerebellum of newborn S100B-EGFP mice, we had previously noted the presence of a large population of S100B-expressing cells, which we assumed to be immature Bergmann glial cells. In the present study, we have drawn on this observation to establish the precise spatio-temporal pattern of S100B gene expression in the embryonic cerebellum. 相似文献400.
Robert B White Anne-Sophie Biérinx Viola F Gnocchi Peter S Zammit 《BMC developmental biology》2010,10(1):21