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Genome sequence and analysis of the tuber crop potato   总被引:11,自引:0,他引:11  
Potato (Solanum tuberosum L.) is the world's most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital crop.  相似文献   
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Photonic crystal fibres (PCFs) offer greatly enhanced design freedom compared to standard optical fibres. For example, they allow precise control of the chromatic dispersion (CD) profile--the frequency dependence of propagation speed--over a broad wavelength range. This permits studies of nonlinear pulse propagation in previously inaccessible parameter regimes. Here we report on spectral broadening of 100-fs pulses in PCFs with anomalously flat CD profiles. Maps of the spectral and spatio-temporal behaviour as a function of power show that dramatic conversion (to both longer and shorter wavelengths) can occur in remarkably short lengths of fibre, depending on the magnitude and shape of the CD profile. Because the PCFs used are single-mode at all wavelengths, the light always emerges in a fundamental guided mode. Excellent agreement is obtained between the experimental results and numerical solutions of the nonlinear wave equation, indicating that the underlying processes can be reliably modelled. These results show how, through appropriate choice of CD, nonlinearities can be efficiently harnessed to generate laser light at new wavelengths.  相似文献   
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针对新一代电子产品密集型的飞机,其系统结构和失效机理复杂、失效模式多样,传统的方法难以对其进行有效健康管理的现状,因此提出了基于海量数据挖掘的飞机PHM研究。首先从系统结构、服役环境、数据来源与存储方式等角度分析了新一代飞机对海量数据挖掘的应用需求;其次论述了基于海量数据挖掘的关键技术,包括数据的预处理、集成管理、聚类、分类、关联、预测等;最后提出了一种基于私有云的飞机PHM海量数据挖掘平台,详细阐述了该平台的总体框架和软硬件结构,该平台为飞机PHM提供了验证平台,对促进飞机PHM的集成与工程化实现具有重大的军事应用意义。  相似文献   
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Autism spectrum disorders comprise a range of neurodevelopmental disorders characterized by deficits in social interaction and communication, and by repetitive behaviour. Mutations in synaptic proteins such as neuroligins, neurexins, GKAPs/SAPAPs and ProSAPs/Shanks were identified in patients with autism spectrum disorder, but the causative mechanisms remain largely unknown. ProSAPs/Shanks build large homo- and heteromeric protein complexes at excitatory synapses and organize the complex protein machinery of the postsynaptic density in a laminar fashion. Here we demonstrate that genetic deletion of ProSAP1/Shank2 results in an early, brain-region-specific upregulation of ionotropic glutamate receptors at the synapse and increased levels of ProSAP2/Shank3. Moreover, ProSAP1/Shank2(-/-) mutants exhibit fewer dendritic spines and show reduced basal synaptic transmission, a reduced frequency of miniature excitatory postsynaptic currents and enhanced N-methyl-d-aspartate receptor-mediated excitatory currents at the physiological level. Mutants are extremely hyperactive and display profound autistic-like behavioural alterations including repetitive grooming as well as abnormalities in vocal and social behaviours. By comparing the data on ProSAP1/Shank2(-/-) mutants with ProSAP2/Shank3αβ(-/-) mice, we show that different abnormalities in synaptic glutamate receptor expression can cause alterations in social interactions and communication. Accordingly, we propose that appropriate therapies for autism spectrum disorders are to be carefully matched to the underlying synaptopathic phenotype.  相似文献   
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Summary A new culturePenicillium farinosum synthesizing roquefortine and 3, 12-dihydroroquefortine was found. UnlikeP. roqueforti, a known producer of these compounds, the culture under study does not synthesize clavine alkaloids. The maximal roquefortine content was observed in the late logarithmic and early stationary growth phases while the maximal 3, 12-dihydroroquefortine content was obtained in the beginning of the stationary phase.Thanks are due to Drs V. M. Adanin and M. Yu. Nefedova for mass- and IR-spectra.  相似文献   
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