始祖鸟摘下“鸟类始祖”光环     

《地理教学》2011,(17):64-64

“鸟类始祖”的光环,始祖鸟整整戴了150年,今天被摘下了。今天出版的英国《自然》杂志刊登中科院古脊椎动物与古人类研究所研究员徐星等人的论文：经最新的系统发育学分析,始祖鸟应属于早期恐爪龙类．而不属鸟类,它不再被认为是最早的鸟类。  相似文献   

Phylogeny of Saccharina and Laminaria (Laminariaceae,Laminariales, Phaeophyta) in sequence-tagged-site markers     

曲洁琼  张静  王绪敏  池姗  刘翠  刘涛 《中国海洋湖沼学报》2014,32(1):22-33

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Bacterial diversity in Arctic marine sediment determined by culture-dependent and-independent approaches     

LIN Xuezheng  WANG Zhen  CHE Shuai  SONG Weizhi  YI Dan 《极地研究(英文版)》2014,(1):46-53

Bacterial diversity in surface sediment from the Arctic Ocean was investigated by culture-dependent and-independent approaches. Conventional culture-dependent techniques revealed 11 strains based on their distinct morphological characteristics on marine Zobell 2216E agar plates. Phylogenetic analysis showed that these isolates belonged to three major lineages of the Bacteria, γ-proteobacteria, Bacteroidetes and Actinobacteria, and that they included 10 genera. Most isolates were psychrotrophic, and NaCl was not necessary for their growth. Furthermore, they exhibited activity of at least one extracellular hydrolytic enzyme at 4°C and had various abilities to assimilate carbon sources. A total of 67 phylotypes were detected among 142 clones based on the 16S rRNA library of the total community DNA and grouped into nine major lineages of bacteria. Phylotypes affiliated with γ-, δ- and ε-proteobacteria accounted for 36.7%, 21.8% and 16.9% of the total clones, respectively. The rest of the clones belonged to Bacteroidetes, α-proteobacteria, Actinobacteria, Fusobacteria, Nitrospirae and an unclassified group.  相似文献   

AreAcila divaricata and Acila mirabilis One Species or Two Distinct Species？ Evidence from COI Mitochondrial DNA     

《青岛海洋大学学报(英文版)》2014,(2):283-289

Acila divaricata （Hinds, 1843） and A. mirabilis （Adams and Reeve, 1850） are common benthic bivalves in China. A number of researchers have proposed that the latter species is a junior synonym of the former species. Because of morphological similarities, it is difficult to distinguish these two species based on visual examination only. For better understanding of their taxon-omy, the mitochondrial CO1 gene fragments of five individuals of A. divaricata from the East China Sea and six individuals of A. mirabilis from the Yellow Sea were sequenced in this study. The phylogenetic relationships of the obtained COI sequences, together with nineteen sequences of three species of the genus Nucula, were analyzed. The pairwise intra- and inter-specific distances for the CO1 sequences ranged from 0.002 to 0.017 and from 0.128 to 0.134, respectively, and no overlap was found. Phylogenetically, A. divaricata and A. mirabilis form distinct clades and cluster into a sister to all other Nucula species. The results indicated that A. di-varicata and A. mirabilis are two distinct species. The differences in the morphology and distribution between the two species were briefly discussed.  相似文献   

Structure of mitochondrial DNA control region of Pholis fangi and its phylogenetic implication     

Lin Li  Hui Zhang  Dianrong Sun  Tianxiang Gao 《中国海洋大学学报(英文版)》2014,13(3):491-496

In this study, the entire mitochondrial DNA （mtDNA） control region （CR） of Pholis fangi was amplified via polymerase chain reaction followed by direct sequencing. The length of the mtDNA CR consensus sequence of P. fangi was 853 bp in length. In accordance with the recognition sites as were previously reported in fish species, the mtDNA CR sequence of P. fangi can be divided into 3 domains, i.e., the extended terminal associated sequence （ETAS）, the central conserved sequence block （CSB）, and the CSB domain. In addition, the following structures were identified in the mtDNA CR sequence of P. fangi：2 ETASs in the ETAS domain （TAS and cTAS）, 6 CSBs in the central CSB domain （CSB-F to CSB-A）, and 3 CSBs in the CSB domain （CSB-1 to CSB-3）. These demonstrated that the structure of the mtDNA CR of P. fangi was substantially different from those of most other fish species. The mtDNA CR sequence of P. fangi contained one conserved region from 656 bp to 815 bp. Similar to most other fish species, P. fangi has no tandem repeat sequences in its mtDNA CR sequence. Phylogenetic analysis based on the complete mtDNA CR sequences showed that there were no genetic differences within P. fangi populations of the same geographical origin and between P. fangi populations of different geographical origins.  相似文献   

高体(鱼狮)(Seriola dumerili)线粒体全基因组测定及结构特征分析     

王开杰  徐永江  崔爱君  柳学周  姜燕  王滨 《海洋与湖沼》2022,53(1):120-132

为快速有效鉴别(鱼师)属鱼类物种、加强(鱼师)鱼遗传多样性管理与种质资源保护,通过Illumina测序技术,获得了东海海域养殖高体(鱼师)(Seriola dumerili)线粒体基因组全序列(16 530bp),碱基组成为A (26.83%)、G (17.6%)、C (30.04%)和T (25.53%), A+T含量为52.36%,且非编码控制区(D-loop)A+T富含61.64%,表现明显的AT偏好性。与其他硬骨鱼一样,高体(鱼师)线粒体基因组包含13条蛋白编码基因, 22个tRNA基因, 2个rRNA基因,除ND6、tRNA^Gln、tRNA^Ala、tRNA^Asn、tRNA^Cys、tRNA^Tyr、tRNA^Ser、tRNA^Glu、tRNA^Pro基因外,其余均位于H链编码;蛋白编码基因中,除COⅠ、COⅡ和ND5的起始密码子分别为ATC、ATA和ATA外,其余10个蛋白编码基因的起始密码子均为ATG,以典型的TAA和TAG为终止密码子,在ND4和Cytb中存在不完全密码子T;除tRNA^Ser-GCT外,其余21个tRNA均为典型三叶草二级结构。比较中国和日本海域高体(鱼师)线粒体基因组发现, CO Ⅰ、CO Ⅱ和ND5蛋白编码基因在起止位置、片段长度及起止密码子上存在显著差异。此外,与同属的黄条(Seriola aureovittata)和五条(鱼师)(Seriola quinqueradiata)的线粒体基因组13个蛋白编码基因进行两两对比分析,结果表明3种(鱼师)属鱼类的蛋白编码基因的相似性在85%~100%之间。基于线粒体基因组全序列构建的系统发育树,成功将高体(鱼师)与其他(鱼师)属鱼类有效区分,高体(鱼师)与长鳍(鱼师)同属一支,亲缘关系最近;黄条(鱼师)和五条(鱼师)聚为一支,亲缘关系最近。  相似文献   

茂兰国家自然保护区喀斯特森林系统发育结构     

王雷宏  杨俊仙  曹翠萍 《山地学报》2020,38(2)

为了揭示茂兰喀斯特森林群落构建的主导力量,检测了11个典型喀斯特群落的系统发育结构以及与生境的关系。结果表明:喀斯特森林群落的系统发育多样性与香农威纳指数、物种丰富度的变化趋势基本是一致的,各群落在物种系统进化上累积的信息相近。黄梨木(Boniodendron minus)—飞蛾槭(Acer oblongum)、荚蒾(Viburnum dilatatum)—鹅掌柴(Schefflera heptaphylla)、青冈(Cyclobalanopsis glauca)—圆果化香(Platycarya longipes)、圆果化香—黄皮(Clausena lansium)、圆果化香—荚蒾、掌叶木(Handeliodendron bodinieri)—光叶槭(Acer laevigatum)、栲(Castanopsis fargesii)—杜英(Elaeocarpus decipiens)、紫树(Nyssa sinensis)—山胡椒(Lindera glauca)林系统发育结构聚集。短叶黄杉(Pseudotsuga brevifolia)—广东松(Pinus kwangtungensis)、短叶黄杉—化香、梧桐(Firmiana simplex)—青冈林系统发育结构均匀。群落系统发育结构分布格局表现为,系统发育结构聚集的群落位于山体的漏斗、沟谷、中坡、下坡、山垭口的部位,而系统发育结构均匀的群落位于山体的上坡、山脊的部位。以地形部位上坡为界划分两种生境,学生氏t检验表明两种生境下群落的系统发育结构差异显著,说明茂兰喀斯特地区山体的地形部位是构建和维持喀斯特森林类型的主导力量。  相似文献   

环境16S rDNA和16S rcDNA序列分析湖光岩玛珥湖的浮游细菌组成     

秦青英  曾永辉  郭倩茹  简纪常  鲁义善  吴灶和 《广东海洋大学学报》2013,(3):1-9

通过提取环境总16S rDNA和总16S rRNA分别构建DNA克隆文库和反转录cDNA文库,并进行克隆测序和序列分析,探讨湖光岩玛珥湖浮游细菌和浮游活性细菌的遗传多样性。结果表明:构建两个水层的4个克隆文库,即1 m和10 m水层总菌的16S rDNA文库和总活性菌的16S rcDNA文库,共获得413条序列,分属15门、32目、52科;1 m水层的rDNA文库与rcDNA文库中Verrucomicrobia类群所占比例最大(36.8%和32.1%),其次为Alphaproteobacteri(a 15.1%和16%)和Betaproteobacteri(a 17.9%和16%);在10 m水层的2个文库中,Alphaproteobacteria类群均占绝对优势,分别为63.5%(rDNA)和43.8%(rcDNA),其次为Verrucomicrobia(11.5%和14.3%),其他细菌类群包括Acidobacteria、Chloroflexi、Firmicutes、待定门OD1、Planctomycetes、Spirochetes和Deltaproteobacteria,比例在0.8%~3.8%之间;在科的水平上,SAR11为湖光岩玛珥湖最为丰富的类群,占总克隆数的26.9%,其中在10 m水层的比例高达51.5%。序列同源性分析表明,绝大多数序列(89.8%)来源于新种,其中19.6%的序列可能来自于新属,69%的序列可能来自于全新的科。湖光岩玛珥湖浮游细菌群落结构较为独特,有大量的浮游细菌种类尚未获得相应的纯培养物,蕴含着丰富而新颖的微生物资源。  相似文献   

印度尼西亚Padang Cermin热泉古菌多样性分析          下载免费PDF全文

沈继红  宋维志  林学政  王帅  Dewi Seswita Zilda 《海洋科学进展》2012,30(4)

通过印度尼西亚苏门答腊岛Padang Cermin热泉环境基因组DNA构建古菌16S rRNA基因文库,并利用PCR-RFLP技术对其古菌多样性和系统发育分析进行了研究.根据限制性内切酶AluⅠ和MspⅠ的特征性酶切图谱,将62个阳性克隆归类为14个分类操作单位(operational taxonomic unit,OTU),文库的覆盖度达90.32％.克隆文库的优势类群为OTU2和OTU1,分别占克隆文库的27.42％和20.96％.从每个OUT中选取一个代表性克隆进行16S rRNA基因的序列测定与系统发育分析,结果表明,测定的Padang Cermin热泉中的古菌均属于泉古菌门,包括热变形菌目(Thermoproteales)、硫还原球菌目(Desulfurococcales)、杂色泉古菌(miscellaneous crenarchaeotic group,MCG)和未培养泉古菌(uncultured Crenarchaeota,UC),该热泉代表性克隆与GenBank数据库已有16S rRNA序列的相似性为91.9％～97.8％,而且与其相似性最高的序列均来自未培养的古菌克隆,由结果可见,Padang Cermin热泉古菌群落与已报道的其他热泉古菌群落的相似性较低,表明该热泉可能具有某些独特的特征,存在着特殊的古菌生态类群.  相似文献   

浙江镇海潮间带沉积物中可培养微生物初步研究     

郑莹  霍颖异 《海洋学研究》2012,30(4):65-71

针对浙江镇海潮间带沉积物样 品,采用纯培养法分离培养海洋微生物,并基于16S rRNA基因序列,开展系统发育学研究,分析沉积物细菌群落结构及多样性。分离获得细菌39株,16S rRNA基因序列分析表明,这些菌株分别属于厚壁菌门Firmicutes(51. 3%)、变形杆菌门Proteobacteria(30.8%)、拟杆菌门Bacteroidetes(15. 4%)和放线菌门Actinobacteria(2. 6%)4个类群。厚壁菌门和变形杆菌门的菌株主要归属于芽孢杆菌纲Bacilli和a-变形杆菌纲Alphaproteobacteria,它们可能在近海海洋生态系统的元素地球化学循环中发挥了重要作用。此外,部分菌株16S rRNA基因序列与已报道物种的相似性较低,可能代表了新的分类单元。研究丰富了浙江近海微生物种质资源,并拓展了对浙江近海可培养细菌多样性的认识,为今后开发利用海洋微生物资源积累了资料。  相似文献