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Changsha, China

Hunan Agricultural University is a public research university located in Changsha, Hunan, China.Founded in 1951, the University was incorporated by two independent colleges under the name "Hunan Agricultural College". Since Hunan was an agricultural powerhouse for the country, Mao Zedong, the founding father of the People's Republic of China, inscribed the school's name on its entrance sign. It changed to its current name in 1994.The institution began with a focus on training students in various agricultural disciplines. After more than a half century's development, the school has evolved into a renowned comprehensive university. In 1978, HAU started to award master's degrees. As of 2007, more than 50,000 students from 31 provinces across China study there, including 24,000 undergraduates, 26,000 continuing education students, 3000 graduate and doctoral students. Wikipedia.

Brassica juncea, a worldwide cultivated crop plant, produces seeds of different colors. Seed pigmentation is due to the deposition in endothelial cells of proanthocyanidins (PAs), end products from a branch of flavonoid biosynthetic pathway. To elucidate the gene regulatory network of seed pigmentation in B. juncea, transcriptomes in seed coat of a yellow-seeded inbred line and its brown-seeded near- isogenic line were sequenced using the next-generation sequencing platform Illumina/Solexa and de novo assembled. Over 116 million high-quality reads were assembled into 69,605 unigenes, of which about 71.5% (49,758 unigenes) were aligned to Nr protein database with a cut-off E-value of 10(-5). RPKM analysis showed that the brown-seeded testa up-regulated 802 unigenes and down-regulated 502 unigenes as compared to the yellow-seeded one. Biological pathway analysis revealed the involvement of forty six unigenes in flavonoid biosynthesis. The unigenes encoding dihydroflavonol reductase (DFR), leucoantho-cyanidin dioxygenase (LDOX) and anthocyanidin reductase (ANR) for late flavonoid biosynthesis were not expressed at all or at a very low level in the yellow-seeded testa, which implied that these genes for PAs biosynthesis be associated with seed color of B. juncea, as confirmed by qRT-PCR analysis of these genes. To our knowledge, it is the first time to sequence the transcriptome of seed coat in Brassica juncea. The unigene sequences obtained in this study will not only lay the foundations for insight into the molecular mechanisms underlying seed pigmentation in B.juncea, but also provide the basis for further genomics research on this species or its allies. Source

Metabolism studies play an important role at various stages of drug discovery and development. Liquid chromatography combined with mass spectrometry (LC/MS) has become a most powerful and widely used analytical tool for identifying drug metabolites. The suitability of different types of mass spectrometers for metabolite profiling differs widely, and therefore, the data quality and reliability of the results also depend on which instrumentation is used. As one of the latest LC/MS instrumentation designs, hybrid ion trap/time-of-flight MS coupled with LC (LC-IT-TOF-MS) has successfully integrated ease of operation, compatibility with LC flow rates and data-dependent MSn with high mass accuracy and mass resolving power. The MSn and accurate mass capabilities are routinely utilized to rapidly confirm the identification of expected metabolites or to elucidate the structures of uncommon or unexpected metabolites. These features make the LC-IT-TOF-MS a very powerful analytical tool for metabolite identification. This paper begins with a brief introduction to some basic principles and main properties of a hybrid IT-TOF instrument. Then, a general workflow for metabolite profiling using LC-IT-TOF-MS, starting from sample collection and preparation to final identification of the metabolite structures, is discussed in detail. The data extraction and mining techniques to find and confirm metabolites are discussed and illustrated with some examples. This paper is directed to readers with no prior experience with LC-IT-TOF-MS and will provide a broad understanding of the development and utility of this instrument for drug metabolism studies. © 2012 John Wiley & Sons, Ltd. Source

Chen D.,University of Strasbourg | Molitor A.,University of Strasbourg | Liu C.,Hunan Agricultural University | Shen W.-H.,University of Strasbourg
Cell Research | Year: 2010

Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 (PRC2) are evolutionarily conserved and their functions are extensively studied in plants, PRC1 differs considerably between animals and plants, and its functions in plants are as yet not well described. Previous studies have identified the Arabidopsis AtRING1a and AtRING1b as homologues of the animal PRC1 subunit RING1. Here, we show that the Atring1a Atring1b double mutant exhibits derepression of embryonic traits during vegetative growth. Accordingly, several key regulatory genes involved in embryogenesis and stem cell activity are ectopically expressed in the mutant. Furthermore, we show that the mutant phenotypes and increased expression of regulatory genes are enhanced by the PRC2 mutant clf. Finally, we show that three homologues of the animal PRC1-subunit ring-finger protein BMI1, AtBMI1a, AtBMI1b and AtBMI1c, can bind with AtRING1a or AtRING1b, and in addition, AtBMI1c can bind with LHP1. The Atbmi1a Atbmi1b double mutant shows derepression of embryonic traits similar to that of the Atring1a Atring1b double mutant. Interestingly, expression levels of AtBMI1a, AtBMI1b and AtBMI1c are elevated in the Atring1a Atring1b mutant and those of AtBMI1c, AtRING1a and AtRING1b are elevated in the Atbmi1a Atbmi1b mutant, suggesting a self-regulatory feedback mechanism. Taken together, our results illuminate crucial functions of the PRC1-like ring-finger components in stable repression of embryonic traits and regulatory genes for proper somatic growth. © 2010 IBCB, SIBS, CAS All rights reserved. Source

Li J.L.,Hunan Agricultural University
Genetics and molecular research : GMR | Year: 2012

Identification of splice sites plays a key role in the annotation of genes. Consequently, improvement of computational prediction of splice sites would be very useful. We examined the effect of the window size and the number and position of the consensus bases with a chi-square test, and then extracted the sequence multi-scale component features and the position and adjacent position relationship features of consensus sites. Then, we constructed a novel classification model using a support vector machine with the previously selected features and applied it to the Homo sapiens splice site dataset. This method greatly improved cross-validation accuracies for training sets with true and spurious splice sites of both equal and different proportions. This method was also applied to the NN269 dataset for further evaluation and independent testing. The results were superior to those obtained with previous methods, and demonstrate the stability and superiority of this method for prediction of splice sites. Source

Gao X.,Xiangtan University | Zhang F.,Hunan Agricultural University | Deng G.,Xiangtan University | Yang L.,Xiangtan University
Organic Letters | Year: 2014

A practical Brønsted acid promoted benzylic C-H functionalization of 2-alkylazaarenes and nucleophilic addition to nitroso compounds was developed under mild conditions. Switched by Brønsted acids, this method can afford azaarene-2-aldimines, azaarene-2-carbaldehyde, or azaarene-2-oximes selectively. No metal, base, oxidant, or other additives were required. © 2014 American Chemical Society. Source

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