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1.
生物分子分类检索表—原理与方法   总被引:26,自引:1,他引:26  
在对大量分子数据比较分析的基础上,对分子检索表这一概念及其遗传学原理进行了探讨,并根据rRNA基因结构特点及进化规律讨论了生物高级阶元以及生物物种界定的分子标准.分子检索原理和方法的阐明,不仅对生物资源的分类鉴定有重要的价值,而且在医学,生态学,古生物学等许多领域中也有广泛的应用前景.  相似文献   

2.
时号  张婧  蒋国芳 《广西科学》2006,13(2):156-160
综述16S rDNA、Cyt b、COⅠ、COⅡ、ND 5等线粒体基因和OPS1、Period、T p i、M p i、EF-1a、W ing less等核基因在蝶类分子系统学中的应用,认为通过系统学的研究,可以明确蝴蝶各分类阶元之间的进化关系,确立一些有争议物种的分类地位以及进行相关物种的系统地理探讨。运用线粒体基因序列与核基因序列相结合来研究生物的系统发育是分子系统学领域的一种必然发展趋势,它可以为我们解决蝶类分类问题提供分子上的证据。  相似文献   

3.
利用分子标记探讨鱼类的系统发育和分子进化已经逐渐成为现代鱼类系统学研究的热点之一。本文综述了核基因在鱼类分子系统发育和分子进化研究中的应用现状及其存在的优缺点。常用的核基因主要有核糖体基因,其中保守的18SrDNA及28SrDNA主要用于研究高级分类阶元;在研究亲缘关系较近的物种以及不同地理种群时,比较常用到的则是ITSs以及SINEs;而RAGs及S7性质独特,也常被用于鱼类的分子系统学研究中。以往的研究主要利用线粒体基因(如Cytb等)研究鱼类的分类和进化,但多年来的研究发现,线粒体基因在研究鲤形目(Cypriniformes)、鲈形目(Perci-formes)等鱼类系统发育时并不能成为最佳的选择。最近的研究表明,核基因能够弥补线粒体基因的缺陷,并可广泛应用于鱼类系统发育研究。然而,核基因的应用也面临着如下问题:1)因核基因重组导致数据分析难度较大;2)鉴定不同类群时存在一定误差;3)单倍性核基因片段较难获得;4)对某些进化时间短的群体的系统发育研究效果较差。随着上述问题的逐步解决,核基因的应用将会更加广泛。  相似文献   

4.
DNA分子标记的广泛应用,使得系统进化、生物地理、群体遗传及人类学等领域的研究得到前所未有的发展.猫科动物分子系统发育关系的重建是目前猫科动物DNA研究的主要方向,进而可以从DNA分子水平上研究猫科动物的进化过程及系统发育关系的本质.本文对DNA分子标记在猫科动物分子系统学中的部分研究成果做了概括.  相似文献   

5.
DNA序列在植物系统进化研究中的应用   总被引:4,自引:0,他引:4  
DNA序列分析已广泛应用于植物系统与进化学研究,根据不同的研究对象和问题选择相对应的DNA序列来进行研究显得十分重要。目前在植物系统与进化学中主要一些DNA的应用,主要是讨论叶绿体基因组(rbcL等)和核基因组(18S,ITS)中的特定DNA序列区段。研究表明,18S,rbcL等编码基因一般适用于较高分类阶元甚至整个种子植物谱系间的系统发育的探讨,而ITS极cpDNA的非编码区序列等因其较快的进化速率多用于较低分类阶元的系统关系研究。  相似文献   

6.
将马克思主义哲学理论同植物分类的具体实际结合起来,论证了植物分类系统、“分类阶元”的客观性,分析了唯物辩证法三大基本规律在植物分类及物种进化中的表现及运用.提出在实际工作中应自觉以马克思主义哲学思想为指导.用科学的世界观和方法论,认识研究植物,才能最终揭示植物分类的本质规律  相似文献   

7.
直翅目是不完全变态昆虫中数量最多的一个类群,全世界已知28000种以上.随着分子生物学技术的发展,线粒体基因组因进化速率快、普遍为母系遗传、极少发生重组等特点而被广泛应用于直翅目各个阶元的系统发育和进化研究中.目前,已有223条直翅目线粒体基因组序列被测定并上传至NCBI数据库,其中包括143条蝗亚目线粒体基因组序列和...  相似文献   

8.
鼠耳蝠属染色体研究进展   总被引:5,自引:0,他引:5  
本文根据作者分析的安徽5种鼠耳蝠核型和文献报道的45种鼠耳蝠核型,对该属染色体组型及进化机制进行了讨论。该属染色体基本上相同,有四个共同特征,仅出现一些微小变化,我国绒鼠耳蝠是该属染色体数最多的一个种,2n=48,NF=54。通常认为,在同一个分类阶元中,染色体数目多,具有较多端部着丝粒染色体的为较原始类型,反之则为较进化类型。因此,绒鼠耳蝠可能是现存鼠耳蝠属动物最原始的种,该属的演化将主要遵循罗伯逊易位和衔接易位。在进化中是否伴随小染色体丢失,尚需进一步研究。  相似文献   

9.
主要从元素阶的角度出发,研究元素的阶常见的性质及结论为进一步研究群的结构的有关性质打下了坚实的基础.探索元的阶和群的阶之间的内在的联系;元的阶和群的类型之间的内在的联系;群中某些元的阶也有着内在的联系.  相似文献   

10.
针对Burgers方程在空间离散格式与时间离散格式方面的精度匹配问题,提出了一种时空耦合谱元方法,求解了一维Burgers方程。求解时在时间及空间方向同时采用了谱元方法离散方程,推导了求解过程,比较了空间方向采用谱元离散结合时间方向分别采用向后欧拉方法、四阶Runge-Kutta方法和四阶Adams-Bashforth方法的数值精度以及时空匹配特性,研究了时间方向网格单元数及插值节点数对时空耦合谱元方法数值精度的影响。研究显示:时空耦合谱元方法能够求解Burgers方程且与传统的时间差分方法相比能够获得更高的数值精度;随着空间方向单元内插值阶数的不断增大,时空耦合谱元方法的数值精度不断提高,且保留了指数阶收敛的特点,具有较好的时空匹配特性;当空间网格划分方式固定时,时间方向上增加单元数或单元内插值阶数,对数值精度提高影响不大,这一结论与相关研究结果一致。研究内容对引入与空间谱元方法精度相匹配的时间离散格式具有指导意义。  相似文献   

11.
多毛纲(Polychaeta)动物系统学的研究进展   总被引:1,自引:0,他引:1  
多毛纲动物以海洋底栖分布为主,在长期的进化过程中,产生了形形色色适应不同环境的形态特征和生活史策略.对其系统学的研究,有助于理解自然界生物多样性的保持机制及其在生物系统进化过程中所发挥的作用.从目前的研究结果来看,多毛纲动物为并系发生,但它们在环节动物系统发生树中的基部类群以及大部分并系群之间的相互关系仍有待确定.今后应该增加各类群有代表性的物种的取样数量,开展形态学特征、生活史策略以及分子遗传标记的综合研究,以期完善多毛纲动物的系统学.  相似文献   

12.
Hypocrea/Trichoderma is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immunocompromised humans and animals, while others can cause damage to cultivated mushroom. With the recent advent of a reliable, BarCode-aided identification system for all known taxa of Trichoderma and Hypocrea, it became now possible to study some of the biological fundamentals of the diversity in this fungal genus in more detail. In this article, we will therefore review recent progress in (1) the understanding of the geographic distribution of individual taxa; (2) mechanisms of speciation leading to development of mushroom diseases and facultative human mycoses; and (3) the possible correlation of specific traits of secondary metabolism and molecular phylogeny.  相似文献   

13.
蚁科昆虫分子系统学研究进展   总被引:3,自引:1,他引:3  
概述了蚁科昆虫分子系统学的研究进展,包括已测序的分类单元和序列片段,蚁科昆虫与其他远缘生物之间互利共生现象的比较研究,与蚁科昆虫相关的分子系统学研究方法的发展,并介绍用于分子系统学研究的昆虫标本的保存方法.  相似文献   

14.
Chemical speciation drives hydrothermal vent ecology   总被引:27,自引:0,他引:27  
The physiology and biochemistry of many taxa inhabiting deep-sea hydrothermal vents have been elucidated; however, the physicochemical factors controlling the distribution of these organisms at a given vent site remain an enigma after 20 years of research. The chemical speciation of particular elements has been suggested as key to controlling biological community structure in these extreme aquatic environments. Implementation of electrochemical technology has allowed us to make in situ measurements of chemical speciation at vents located at the East Pacific Rise (9 degrees 50' N) and on a scale relevant to the biology. Here we report that significant differences in oxygen, iron and sulphur speciation strongly correlate with the distribution of specific taxa in different microhabitats. In higher temperature (> 30 degrees C) microhabitats, the appreciable formation of soluble iron-sulphide molecular clusters markedly reduces the availability of free H2S/HS- to vent (micro)organisms, thus controlling the available habitat.  相似文献   

15.
安徽歙县清凉峰自然保护区苔藓植物区系研究   总被引:2,自引:0,他引:2  
本文旨在研究安徽县清凉峰苔藓植物区系。从1877份苔藓植物标本中,鉴定出417种(包括亚种、变种、变型),隶属于62科,169属,并根据种的分布范围划出下列区系成分:1.欧亚—北美成分(97种,23.26%);2.东亚—北美成分(9种,2.15%);3.欧亚大陆成分(19种,4.56%);4.东亚成分(179种,42.9%);5.北半球广布成分(6种,1.43%);6.中国特有成分(20种,4.79%);7.新热带成分(9种,2.15%);8.旧热带成分(63种,15.1%)。进而提出,清凉峰苔藓植物区系以东亚成分为主,区系组成表现为泛热带植物区系向北渗透过渡的复杂性。  相似文献   

16.
Partial DNA sequences of cytochrome b gene (mtDNA) were successfully retrieved from Late Pleistocene fossil bone of Mammuthus primigenius collected from the Xiguitu County (Yakeshi), Inner Mongolia Autonomous Region and from Zhaodong, Harbin of Heilongjiang Province in northern China. Two ancient DNA fragments (109 bp and 124 bp) were authenticated by reproducible experiments in two different laboratories and by phylogenetic analysis with other Elephantidae taxa. Phylogenetic analysis using these sequences and published data in either separate or combined datasets indicate unstable relationship among the woolly mammoth and the two living elephants, Elephas and Loxodonta. In addition to the short sequences used to attempt the long independent evolution of Elephantidae terminal taxa, we suggest that a high intra-specific diversity existed in Mammuthus primigenius crossing both spatial and temporal ranges, resulting in a complex and divergent genetic background for DNA sequences so far recovered. The high genetic diversity in the extinct woolly mammoth can explain the apparent instability of Elephantidae taxa on the molecular phylogenetic trees and can reconcile the apparent paradox regarding the unresolved Elephantidae trichotomy.  相似文献   

17.
Partial DNA sequences of cytochrome b gene (mtDNA) were successfully retrieved from Late Pleistocene fossil bone of Mammuthus primigenius collected from the Xiguitu County ( Yakeshi), Inner Mongolia Autonomous Region and from Zhaodong, Harbin of Heilongjiang Province in northern China. Two ancient DNA fragments (109 bp and 124 bp) were authenticated by reproducible experiments in two different laboratories and by phylogenetic analysis with other Elephantidae taxa. Phylogenetic analysis using these sequences and published data in either separate or combined datasets indicate unstable relationship among the woolly mammoth and the two living elephants, Elephas and Loxodonta . In addition to the short sequences used to attempt the long independent evolution of Elephantidae terminal taxa, we suggest that a high intra-specific diversity existed in Mammuthus primigenius crossing both spatial and temporal ranges, resulting in a complex and divergent genetic background for DNA sequences so far recovered. The high genetic diversity in the extinct woolly mammoth can explain the apparent instability of Elephantidae taxa on the molecular phylogenetic trees and can reconcile the apparent paradox regarding the unresolved Elephantidae trichotomy.  相似文献   

18.
Partial DNA sequences of cytochrome b gene (mtDNA) were successfully retrieved from Late Pleistocene fossil bone of Mammuthus primigenius collected from the Xiguitu County (Yakeshi), Inner Mongolia Autonomous Region and from Zhaodong, Harbin of Heilongjiang Province in northern China. Two ancient DNA fragments (109 bp and 124 bp) were authenticated by reproducible experiments in two different laboratories and by phylogenetic analysis with other Elephantidae taxa. Phylogenetic analysis using these sequences and published data in either separate or combined datasets indicate unstable relationship among the woolly mammoth and the two living elephants, Elephas and Loxodonta. In addition to the short sequences used to attempt the long independent evolution of Elephantidae terminal taxa, we suggest that a high intra-specific diversity existed in Mammuthus primigenius crossing both spatial and temporal ranges, resulting in a complex and divergent genetic background for DNA sequences so far recovered. The high genetic diversity in the extinct woolly mammoth can explain the apparent instability of Elephantidae taxa on the molecular phylogenetic trees and can reconcile the apparent paradox regarding the unresolved Elephantidae trichotomy.  相似文献   

19.
Evolutionary distinctiveness of the endangered Kemp's ridley sea turtle   总被引:5,自引:0,他引:5  
B W Bowen  A B Meylan  J C Avise 《Nature》1991,352(6337):709-711
The endangered Kemp's ridley sea turtle (Lepidochelys kempi) nests almost exclusively at a single locality in the western Gulf of Mexico, whereas the olive ridley (L. olivacea) nests globally in warm oceans. Morphological similarities between kempi and olivacea, and a geographical distribution that "...makes no sense at all under modern conditions of climate and geography", raise questions about the degree of evolutionary divergence between these taxa. Analysis of mitochondrial (mt) DNA restriction sites shows that Kemp's ridley is distinct from the olive ridley in matriarchal phylogeny, and that the two are sister taxa with respect to other marine turtles. Separation of olive and the Kemp's ridley lineages may date to formation of the Isthmus of Panama, whereas the global spread of the olive ridley lineage occurred recently. In contrast to recent examples in which molecular genetic assessments challenged systematic assignments underlying conservation programmes, our mtDNA data corroborate the taxonomy of an endangered form.  相似文献   

20.
基于18S rRNA基因序列以近缘植物Paeonia suffruticosa和Mahonia bealei为外类群,采用邻接法(Neighbor-joining methods,NJ)和最大简约法(Maximum parsimony,MP)对毛茛科Ranunculaceae 6属12种植物的系统发育关系进行了分析.结果表明,18S rRNA基因序列长度范围在1807~1810bp之间,系统树显示耧斗菜属Aquilegia与唐松草属Thalictrum,升麻属Cimicifuga与乌头属Aconitu  相似文献   

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