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61.
Automatic classification within families of transposable elements: Application to the mariner Family
Jacques-Deric Rouault Nathalie Casse Benoît Chénais Aurélie Hua-Van Jonathan Filée Pierre Capy 《Gene》2009
The higher levels of the classification of transposable elements (TEs) from Classes to Superfamilies or Families, is regularly updated, but the lower levels (below the Family) have received little investigation. In particular, this applies to the Families that include a large number of copies. In this article we propose an automatic classification of DNA sequences. This procedure is based on an aggregation process using a pairwise matrix of distances, allowing us to define several groups characterized by a sphere with a central sequence and a radius. This method was tested on the mariner Family, because this is probably one of the most extensively studied Families. Several Subfamilies had already been defined from phylogenetic analyses based on multiple alignments of complete or partial amino-acid sequences of the transposase. The classification obtained here from DNA sequences of 935 items matches the phylogenies of the transposase. The rate of error from a posteriori re-assignment is relatively low. 相似文献
62.
Eukaryotic RNA-dependent RNA polymerases (RdRPs, encoded by RDR genes) play critical roles in developmental regulation, maintenance of genome integrity, and defense against foreign nucleic acids. However, the phylogenetic relationship of RDRs remains unclear. From available genome sequences, we identified 161 putative RDR genes from 56 eukaryotes, ranging from protists to multicellular organisms, including plants, fungi and invertebrate animals, such as nematodes, lancelet and sea anemone. On the other hand, we did not detect RDR homologs in vertebrates and insects, even though RNA interference functions in these organisms. Our phylogenetic analysis of the RDR genes suggests that the eukaryotic ancestor might have had three copies, i.e. RDRα, RDRβ and RDRγ. These three ancient copies were also supported by the patterns of protein sequence motifs. Further duplication events after the divergence of major eukaryotic groups were supported by the phylogenetic analyses, including some that likely occurred before the separation of subgroups within each kingdom. We present a model for a possible evolutionary history of RDR genes in eukaryotes. 相似文献
63.
广东竹亚科新组合及新异名 总被引:2,自引:0,他引:2
报道了广东竹亚科13新组合,1新名称和3新异名,其中筋竹属3新组合1新名称,牡竹属4新组合,青篱竹属5组合1新异名,箬竹属2新异名及方竹属1新组合. 相似文献
64.
2007年5月28日公布的《中华人民共和国进境植物检疫性有害生物名录》中,隶属于鞘翅目象虫总科的2种象虫的学名需要更正。李虎象Rhynchites cupreus(L.)正确的学名应为Involvulus cupreus(L.);西瓜船象Baris granulipennis(Tournier)正确的学名应为Acythopeus granulipennis(Tournier),文章根据《国际动物命名法规》对上述种类的学名变更进行论述。同时,文章还讨论进境植物检疫过程中应该注意的问题。 相似文献
65.
The capability of iTRAQ (isotope tags for relative and absolute quantification) reagents coupled with matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) as a qualitative and quantitative technique for the analysis of complicated protein pharmaceutical mixtures was evaluated. Mixtures of Somavert and Miacalcin with a small amount of bovine serum albumin (BSA) as an impurity were analyzed. Both Somavert and Miacalcin were qualitatively identified, and BSA was detected at levels as low as 0.8 mol%. Genotropin and Somavert were compared in a single experiment, and all of the distinct amino acid residues from the two proteins were readily identified. Four somatropin drug products (Genotropin, Norditropin, Jintropin, and Omnitrope) were compared using the iTRAQ/MALDI-MS method to determine the similarity between their primary structures and quantify the amount of protein in each product. All four product samples were well labeled and successfully compared when a filtration cleanup step preceded iTRAQ labeling. The quantitative accuracy of the iTRAQ method was evaluated. In all cases, the accuracy of experimentally determined protein ratios was higher than 90%, and the relative standard deviation (RSD) was less than 10%. The iTRAQ and global internal standard technology (GIST) methods were compared, and the iTRAQ method provided both higher sequence coverage and enhanced signal intensity. 相似文献
66.
67.
T.N. Corbisier L.S.H. Soares M.A.V. Petti E.Y. Muto M.H.C. Silva J. McClelland I. Valiela 《Aquatic Ecology》2006,40(3):381-390
A dual isotope approach was used to assess the relative importance of terrestrial vegetation detritus and other primary producers in the trophic web of Flamengo Sound (Ubatuba, SP), SE Brazil, surrounded by the Atlantic Rain Forest. Primary producers showed distinct C signatures and the observed values suggest that little terrestrial or bulk sediment organic matter enter the food web of the sound. Suspended particulate organic matter (POM, supports the bulk of the consumers, with some contribution by macroalgae . Consumers C values ranged from −17.4 to . At least three trophic levels were detectable in the food web. The N value of POM was , while that of sediment and detritus was . The N values of suspension feeding benthic invertebrates were 8.2–, deposit feeders 8.3–, and carnivores 10.7–. Values for fishes were for detritivore, 11.4– for benthic feeders, 12.4– for zooplanktivores, and for piscivores/benthic invertebrate feeders. Squid mean value was . There is a reasonable agreement between feeding habits information from the literature and N values from this study. In the sound, the first and second trophic steps seem to be about 1– higher than those of similar organisms studied in temperate waters and this may reflect an input of allochtonous anthropogenic nitrogen enriched in 15N from human activities. 相似文献
68.
报道了中国产12种苔藓植物染色体数目,结果为:壶苞苔Blasia pusilla,n=9;艳
绿光苔Cyathodium smaragdinum,n=9;紫背苔Plagiochasma rupestre,n=9;石地钱Rebou
lia hemisphaerica,n=9;宽片叶苔Riccardia latifrons,n=10;尖叶美喙藓Eurhynchium eustegium,n=11;东亚沼羽藓Helodium sachalinense,n=11;白齿藓Leucodon sciuroides, 相似文献
69.
70.
一种报春花的新命名 总被引:1,自引:0,他引:1
胡启明 《热带亚热带植物学报》2000,8(3):214-214
由于种加词相重,陈封怀、胡启明(1990)发表的新种Pimula exscapa Chen et C.M.Hu(holotype,S.G.Xu 3568 KUN)应是Primula exscapa Hegetschw.,FL Schw.195.1838的晚出同名,应给予重新命名. 相似文献