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1.
In this study, we investigated the molecular phylogeny of 64 clinical isolates which were identified as Sporothrix schenckii sensu lato by morphological identification. All of the strains were isolates from patients from several provinces in China. The phylogeny was inferred by DNA sequence analyses based on datasets of the ribo- somal internal transcribed spacer （ITS） and a combined ITS and partial 13-tubulin region. Reference sequences were retrieved from GenBank. Results showed that all of the isolates were clustered in a distinct clade with a type of Spo- rothrix globosa. Our analysis showed that S. globosa is the causal agent of the tested sporotrichosis in China, rather than S. schenckii that was generally believed to be the case. The existence of S. schenckii in China remains to be confirmed. This study improved our understanding of the distribution of the species in S. schenckii complex. 相似文献
2.
ITS2是真核生物rRNA基因的重要组成部分,在rRNA基因加工成熟过程中起到至关重要的作用．ITS2的高级结构相对保守,对其序列进化表现一定程度的限制作用．ITS2保守的结构域和二级结构为广范围遗传距离排序提供了重要的技术保障．正因为如此,ITS2在高级阶元系统发育关系分析中展示出诱人的前景． 相似文献
3.
利用ITS序列分析技术对胡枝子属植物进行了亲缘关系分析,探讨其遗传多样性及其亲缘关系,试图为胡枝子属植物资源开发利用提供依据。将从Gen Bank检索获得的24条胡枝子属植物(19个种)的ITS序列做系统发育分析,Clustal 2.0软件进行序列比对,Mega4.0计算序列核苷酸比例及遗传距离,并构建邻接树(Neighbor-joining tree,NJ Tree)。胡枝子的19种植物ITS序列全长为622 bp,变异位点占总序列的16.6%;K-2-P遗传距离为0.001-0.085;鉴定成功率为57.9%,19种胡枝子可以聚为3支,与形态学分类结果并不完全一致。 相似文献
4.
通过比较13种鬣蜥科沙蜥属蜥蜴的16S rRNA部分序列，并以同科的长鬣蜥属长鬣蜥为外群构建NJ树、ML树和MP树，以探讨该属13种蜥蜴的系统发生关系．PAUP分析结果显示这13种沙蜥分成两个类群，呈并系关系，并且NJ树的结果与ML树和MP树划分结果不同．而MEGA结果支持基于形态学、生态环境和核型分析对该13种的沙蜥的划分，同时NJ树中的13种沙蜥属单系群、 相似文献
5.
Ultrastructure and phylogeny of Ustilago coicis 总被引：1，自引：0，他引：1
Jing-ze Zhang Pei-gang Guan Gang Tao Mohammad Reza Ojaghian Kevin David Hyde 《Journal of Zhejiang University. Science. B》2013,14(4):336-345
Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town, Jinyun County, Zhejiang Province of China. In this paper, ultrastructural assessments on fungus-host interactions and teliospore development are presented, and molecular phylogenetic analyses have been done to elucidate the phylogenetic placement of the taxon. Hyphal growth within infected tissues was both intracellular and intercellular and on the surface of fungus-host interaction, and the fungal cell wall and the invaginated host plasma membrane were separated by a sheath comprising two distinct layers between the fungal cell wall and the invaginated host plasma membrane. Ornamentation development of teliospore walls was unique as they appeared to be originated from the exosporium. In addition, internal transcribed spacer (ITS) and large subunit (LSU) sequence data showed that U. coicis is closely related to Ustilago trichophora which infects grass species of the genus Echinochloa (Poaceae). 相似文献
6.
以线粒体DNA的Cyt b基因全序列作为分子标记,对雀形目(Passeriformes)6科15种鸟类的分类地位及系统发生关系进行了分析.结果显示:全序列中含有变异位点454个,简约信息位点337个.采用邻接法、最大简约法、最大似然法和贝叶斯法分别构建了系统发生树及其合一树,结果表明:黄鹂科(Oriolidae)首先分化出来,接着依次分化出卷尾科(Docruridae)、鸦科(Corvidae)、伯劳科(Laniidae)、河乌科(Cinclidae)和椋鸟科(Sturnidae)鸟类;这6科鸟类构成一个单系群,在这一单系群里椋鸟科是最晚分化出的类群. 相似文献
7.
Ya-e Zhao Zheng-hang Wang Yang Xu Ji-ru Xu Wen-yan Liu Meng Wei Chu-ying Wang 《Journal of Zhejiang University. Science. B》2012,13(10):763-768
To our knowledge, few reports on Demodex studied at the molecular level are available at present. In this study our group, for the first time, cloned, sequenced and analyzed the chitin synthase (CHS) gene fragments of Demodex folliculorum, Demodex brevis, and Demodex canis (three isolates from each species) from Xi’an China, by designing specific primers based on the only partial sequence of the CHS gene of D. canis from Japan, retrieved from GenBank. Results show that amplification was successful only in three D. canis isolates and one D. brevis isolate out of the nine Demodex isolates. The obtained fragments were sequenced to be 339 bp for D. canis and 338 bp for D. brevis. The CHS gene sequence similarities between the three Xi’an D. canis isolates and one Japanese D. canis isolate ranged from 99.7% to 100.0%, and those between four D. canis isolates and one D. brevis isolate were 99.1%–99.4%. Phylogenetic trees based on maximum parsimony (MP) and maximum likelihood (ML) methods shared the same clusters, according with the traditional classification. Two open reading frames (ORFs) were identified in each CHS gene sequenced, and their corresponding amino acid sequences were located at the catalytic domain. The relatively conserved sequences could be deduced to be a CHS class A gene, which is associated with chitin synthesis in the integument of Demodex mites. 相似文献
8.
James J. Smith Kendra Spence Cheruvelil Stacie Auvenshine 《CBE life sciences education》2013,12(3):542-552
Phylogenetic trees provide visual representations of ancestor–descendant relationships, a core concept of evolutionary theory. We introduced “tree thinking” into our introductory organismal biology course (freshman/sophomore majors) to help teach organismal diversity within an evolutionary framework. Our instructional strategy consisted of designing and implementing a set of experiences to help students learn to read, interpret, and manipulate phylogenetic trees, with a particular emphasis on using data to evaluate alternative phylogenetic hypotheses (trees). To assess the outcomes of these learning experiences, we designed and implemented a Phylogeny Assessment Tool (PhAT), an open-ended response instrument that asked students to: 1) map characters on phylogenetic trees; 2) apply an objective criterion to decide which of two trees (alternative hypotheses) is “better”; and 3) demonstrate understanding of phylogenetic trees as depictions of ancestor–descendant relationships. A pre–post test design was used with the PhAT to collect data from students in two consecutive Fall semesters. Students in both semesters made significant gains in their abilities to map characters onto phylogenetic trees and to choose between two alternative hypotheses of relationship (trees) by applying the principle of parsimony (Occam''s razor). However, learning gains were much lower in the area of student interpretation of phylogenetic trees as representations of ancestor–descendant relationships. 相似文献
9.
为了检验狐米草低能重离子各诱变株系在表型、生物量和内部生理生化状态发生变化的同时,其遗传物质DNA是否发生改变,试验检测了狐米草对照株系与各诱变株系的ITS序列.结果发现,所检测的狐米草10个诱变株系的ITS序列与对照株系完全一致,仅与美国德克萨斯州和路易斯安那州的狐米草株系差别1-2个碱基,显示低能重离子束诱变并没有导致狐米草株系在ITS区段发生变异. 相似文献
10.
采用18S rDNA序列为基础的系统分析方法,对采自嘉陵江磁器口江段的黄颡单尾虫Unicauda pelteobagrus Ma,1998进行了分子系统学研究,首次给出了黄颡单尾虫的SSU rDNA序列信息．同时基于18S rDNA数据、遗传距离和系统树特征讨论了尾单尾虫Unicauda caudatus和黄颡单尾虫的系统关系．结果表明,尾单尾虫与尾碘泡虫的系统关系较近,而与黄颡单尾虫系统关系较远,不支持将尾单尾孢虫和黄颡单尾虫同置于单尾虫属中,并对单尾虫属的有效性提出质疑． 相似文献
11.
根的溢泌物与根际微生物关系的研究 总被引：7，自引：0，他引：7
焦海华 《洛阳师范学院学报》2003,22(2):88-90
从山西长治不同区域分布的松树、柏树、苹果树的根际及耕种 2 0年以上的耕地里 ,在不同的季节、不同深度采集土壤样品 .采用稀释混合平板法分离培养和活菌计数 ,研究了根际微生物种群与植物根溢泌活动之间的相互关系 .松树、柏树根际微生物种类和数量 ,在不同季节、不同土壤深度差别不显著 .苹果树根际、耕地土壤中微生物无论从种类和数量上 ,均与季节变化、土壤深度有相关性 相似文献
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13.
Ya-e Zhao Jun-xian Ma Li Hu Li-ping Wu Manuel De Rojas 《Journal of Zhejiang University. Science. B》2013,14(9):829-836
For a long time, classification of Demodex mites has been based mainly on their hosts and phenotypic characteristics. A new subspecies of Demodex folliculorum has been proposed, but not confirmed. Here, cox1 partial sequences of nine isolates of three Demodex species from two geographical sources (China and Spain) were studied to conduct molecular identification of D. folliculorum. Sequencing showed that the mitochondrial cox1 fragments of five D. folliculorum isolates from the facial skin of Chinese individuals were 429 bp long and that their sequence identity was 97.4%. The average sequence divergence was 1.24% among the five Chinese isolates, 0.94% between the two geographical isolate groups (China (5) and Spain (1)), and 2.15% between the two facial tissue sources (facial skin (6) and eyelids (1)). The genetic distance and rate of third-position nucleotide transition/transversion were 0.0125, 2.7 (3/1) among the five Chinese isolates, 0.0094, 3.1 (3/1) between the two geographical isolate groups, and 0.0217, 4.4 (3/1) between the two facial tissue sources. Phylogenetic trees showed that D. folliculorum from the two geographical isolate groups did not form sister clades, while those from different facial tissue sources did. According to the molecular characteristics, it appears that subspecies differentiation might not have occurred and that D. folliculorum isolates from the two geographical sources are of the same population. However, population differentiation might be occurring between isolates from facial skin and eyelids. 相似文献
14.
Zhang Jing-ze Liu Lu-ning Fiore-Donno Anna-Maria Xu Tong 《Journal of Zhejiang University. Science. B》2007,8(12):896-899
A known species, Physarum melleum, was found fruiting on living leaves of Dendrobium candidum, which was collected in China in 2004. Its morphological characters were revealed by light microscopy (LM), environmental
scanning electron microscopy (ESEM) and scanning electron microscopy (SEM). Character variations were distinguished by its
olive-yellow peridium and its always thinner capillitium containing globulose granular material between the large calcareous
nodes. The calcium carbonate granules, deposited on stalks, peridium and hypothallus as well as within stalks, were globose
and smooth.
Project (No. 2001BA744C) supported by the 10th Five-year National Key Technologies R & D Program, China 相似文献
15.
武汉城市圈建立智能交通运输管理系统研究 总被引：1，自引：1，他引：0
陈贞 《黄石理工学院学报(人文社科版)》2009,26(4):7-9,18
智能交通运输管理系统（ITS）是现代化的高科技与交通运输系统相结合的产物,它的主要优点是无需增加太多的投入就可以提高现有交通运输系统的效率。ITS在发达国家受到极大重视并被广泛应用,我国则处于地方试点的阶段。如果能在武汉城市圈内建立和发展智能交通运输管理系统,必将对城市圈内的交通运输业乃至全省的社会经济发展产生巨大的促进作用。 相似文献
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17.
基于氨基酸的五字母模型,提出蛋白质序列的一种二维图形表示方法,然后证明这种图是非退化的.最后用该方法给出了8个物种的β球蛋白序列的图形表示. 相似文献
18.
来自南阳玉米穗腐病样品的玉蜀黍赤霉菌的分离及其特性鉴定 总被引：1，自引：1，他引：0
2009年在河南省西峡县、唐河县采集得到玉米穗腐病样品,样品经病原分离和单孢子纯化后,得到3个菌株Gz1、Gz2与Gz3（GenBank登记号分别为：HM769949、HM769950与HQ110051）.在致病性测定的基础上进行了rDNA-ITS序列分析,其结果表明3个菌株均与玉蜀黍赤霉菌（Gibberella zeae）有99%的同源性,用软件MEGA version 4.0构建基于r DNA-ITS序列系统发育树,3个菌株均与玉蜀黍赤霉菌在100%boostrap水平相聚于同一群;菌株Gz1、Gz2与Gz3的菌落形态和分生孢子特征均与文献描述的玉蜀黍赤霉菌相符.为此实验选取了Gz1作为代表性菌株对玉蜀黍赤霉菌的部分生物学特性做了研究. 相似文献
19.
YE Qian QIU Ying-xiong QUO Yan-qi CHEN Jian-xin YANG Shu-zhen ZHAO Ming-shui FU Cheng-xin 《Journal of Zhejiang University. Science. B》2006,7(11)
INTRODUCTION Calycanthaceae consists of three genera: Caly-canthus, Chimonanthus and Sinocalycanthus. Chi-monanthus and Sinocalycanthus are restricted toChina, and Calycanthus is distributed in NorthAmerica (Zhang and Liu, 1998). Sinocalycanthuschinensis Cheng et S.Y. Chang, the only representa-tive in the genus Sinocalycanthus, is a deciduousshrub endemic to China. Both biological and an-thropological causes have led to the recent decline ofthe species, which is now known from onl… 相似文献