首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 9 毫秒
1.
核基因在两栖爬行动物分子系统学中的研究进展   总被引:1,自引:0,他引:1  
从DNA水平探索生物进化的理论、生物类群的演化历史具有重要的意义,应用DNA序列研究生物的系统发育和进化规律成为当前分子系统学研究的热点,与线粒体DNA相比,核基因由于包含有更加丰富的生物学信息,运用核基因序列或将核基因序列与线粒体基因序列相结合研究两栖爬行动物的系统发育,正成为分子系统学领域的新的发展趋势.Rag-1、Rag-2、tyrosinase、rhodopsin、C-mos等核基因已在两栖爬行动物分子系统学中得到了广泛的应用.由于目前的技术手段等诸多因素,限制了更多的核基因用于两栖爬行动物分子系统学研究.为此简要介绍了目前核基因在两栖爬行动物分子系统学方面的研究进展,并分析了核基因序列在分子系统学应用上面临的问题和应用前景.  相似文献   

2.
The publication of Systematics Agenda 2000 in February, 1994 represented an historic event in the collaboration of the systematic biology community designed to set a research agenda for a twenty five year period across the areas of basic and applied systematics. How the community came to take the initiative to produce such a consensus is outlined. Of special interest is the emergence of the Systematics Agenda 2000 initiative from a North American perspective to a truly global enterprise.  相似文献   

3.
串珠藻目分子系统学研究进展   总被引:1,自引:0,他引:1  
姚戈  谢树莲 《植物学通报》2007,24(2):141-146
串珠藻目(Batrachospermales)是淡水红藻中最主要的类群。近年来,应用DNA序列分析探讨串珠藻目的系统发育,并与传统的形态学和生态学特征相结合,为串珠藻目系统学研究拓展了新的思路。本文回顾了串珠藻目的建立及其所含类群的研究历史,归纳了目前在串珠藻目系统发育与进化研究中常用的分子标记方法,其中包括核基因组的18SrDNA、26SrDNA和ITS序列,叶绿体基因组的rbcL序列,线粒体基因组的cox9.-3序列,以及新兴的ISSR技术,并对各种分子标记的特点及适用范围做了评述。结果表明,ITS序列多适用于种群分化及相近种间遗传分析,ISSR标记适用于种下分类群间及同一种群不同个体间基因多态性分析,cox2-3序列在一定程度上也可用于同一种群不同个体间的基因多态性分析,而18SrDNA与rbcLFF列既可用于种问关系分析,又可用于更高水平分析的构建系统树。这些分子枥对己已被证明在研究串珠藻目系统地理、物种起源和散布机制方面有着广泛的应用前景。同时,本文对串珠藻目分子系统学研究的最新进展也进行了概述,并对今后的研究方向做了展望。  相似文献   

4.
文中综述了核糖体基因在黏菌分子系统学研究中应用现状,并就目前黏菌分子系统中存在的问题及发展方向提出了看法。  相似文献   

5.
分子生物学技术的发展以及计算机的广泛使用给菌物系统学在分子水平上带来了革命性变化,本文简要回顾了菌物分子系统学研究现状与分析方法,并就目前菌物分子系统学中存在的问题以及该研究的发展方向提出了一些看法。  相似文献   

6.
羊肚菌属分子系统学研究进展*   总被引:5,自引:0,他引:5  
胡克兴  董雪  范黎   《微生物学通报》2004,31(6):115-119
简要介绍羊肚菌属系统学研究现状,概述了当前国内外羊肚菌属分子系统学研究进展。  相似文献   

7.
虫草属分子系统学研究现状   总被引:11,自引:0,他引:11  
蒋毅  姚一建 《菌物研究》2004,2(1):58-67
近年来的分子系统学研究结果表明 ,麦角菌目 (Clavicipitales)与肉座菌目 (Hypocreales)以及虫草属[Cordyceps(Fr.)Link]与麦角菌科 (Clavicipitaceae)内的有关种属关系密切 ,但虫草属为一多系群 ,其中只有新虫草亚属的种类形成单系群。虫草属种类的进化与寄主有一定的关系 ,有关研究显示它们在亲缘关系相差很大的寄主之间多次转移。多个独立的ITS序列研究表明 ,阔孢虫草 (CordycepscrassisporaM .Zangetal.)、甘肃虫草(CordycepsgansuensisK .Y .Zhangetal.)、多轴虫草 (CordycepsmultiaxialisM .Zang&Kinjo)、尼泊尔虫草 (CordycepsnepalensisM .Zang&Kinjo)与冬虫夏草 [Cordycepssinensis(Berk.)Sacc.]为同一物种 ;RAPD和ITS序列分析还显示不同地理分布的冬虫夏草存在明显的遗传分化。分子生物学方法在确定有性型与无性型的关系上已经为多种虫草菌提供了有力的证据。本文主要对虫草属分子系统学研究现状进行了综述 ,同时就分子生物学研究中的取样问题、一些分子方法的适用范围以及有性型与无性型的关系等问题进行了讨论。  相似文献   

8.
Mediterranean reports of Gracilariaceae species, in particular those assigned to the G. verrucosa complex, were re-examined with the use of molecular tools, in order to verify their systematic position and better understand their distribution. Within this complex, we recognized four distinct taxa: Gracilariopsis longissima, Gracilaria gracilis, Gracilaria longa and a possible new species. The rbcL gene sequences, together with those of other terete Mediterranean entities, were included in a broad molecular phylogeny of the family. The reproductive characters of the studied taxa do not fit completely with published hypothesis on the generic and intrageneric relationships, suggesting that the anatomy of some subgroups should be better characterized.  相似文献   

9.
Phylogenetic studies of ticks have been increasing in recent years, particularly in the use of molecular data. However, all of the studies to date are either limited to the mitochondrial genome or to a few nuclear ribosomal genes. There is a need to explore the use of nuclear protein-encoding genes because these genes direct most aspects of the phenotypic traits in the development of an organism. We report here the test of a nuclear protein-encoding gene, RNA polymerase II, for the phylogenetic study of ticks. Thirty-eight ticks representing 26 species of hard and soft ticks were chosen for the study. The pairwise divergences among sampled species are ranged from 0.3 to 15.2% and most of the substitutions are transitions. In addition, the nucleotide composition is not obviously biased in POL II gene. The trees inferred from the POL II sequences using maximum parsimony (MP), neighbor joining (NJ), and maximum likelihood (ML) by PAUP* and MrBayes are largely concordant with the existing phylogenies. Our study demonstrated that POL II gene sequences contain strong phylogenetic signals in ticks at the generic and higher levels. POL II has proven to be a useful gene for resolving tick phylogeny. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
Biologists and historians often present natural history and molecular biology as distinct, perhaps conflicting, fields in biological research. Such accounts, although supported by abundant evidence, overlook important areas of overlap between these areas. Focusing upon examples drawn particularly from systematics and molecular evolution, I argue that naturalists and molecular biologists often share questions, methods, and forms of explanation. Acknowledging these interdisciplinary efforts provides a more balanced account of the development of biology during the post-World War II era. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

11.
Cladistic analyses of plastid DNA sequences rbcL and trnL-F are presented separately and combined for 48 genera of Amaryllidaceae and 29 genera of related asparagalean families. The combined analysis is the most highly resolved of the three and provides good support for the monophyly of Amaryllidaceae and indicates Agapanthaceae as its sister family. Alliaceae are in turn sister to the Amaryllidaceae/Agapanthaceae clade. The origins of the family appear to be western Gondwanaland (Africa), and infrafamilial relationships are resolved along biogeographic lines. Tribe Amaryllideae, primarily South African, is sister to the rest of Amaryllidaceae; this tribe is supported by numerous morphological synapomorphies as well. The remaining two African tribes of the family, Haemantheae and Cyrtantheae, are well supported, but their position relative to the Australasian Calostemmateae and a large clade comprising the Eurasian and American genera, is not yet clear. The Eurasian and American elements of the family are each monophyletic sister clades. Internal resolution of the Eurasian clade only partially supports currently accepted tribal concepts, and few conclusions can be drawn on the relationships of the genera based on these data. A monophyletic Lycorideae (Central and East Asian) is weakly supported. Galanthus and Leucojum (Galantheae pro parte) are supported as sister genera by the bootstrap. The American clade shows a higher degree of internal resolution. Hippeastreae (minus Griffinia and Worsleya) are well supported, and Zephyranthinae are resolved as a distinct subtribe. An Andean clade marked by a chromosome number of 2n = 46 (and derivatives thereof) is resolved with weak support. The plastid DNA phylogenies are discussed in the context of biogeography and character evolution in the family.  相似文献   

12.
13.
孢粉学是解决植物分类中疑难类群物种微形态分化的重要方法, 随着分子系统学的发展, 结合这两门学科的优势可以更加有效地解决疑难类群的分类学问题。鳞盖蕨属(Microlepia)是一个分类困难的疑难类群, 采用孢粉学与分子系统学一一对应的方法, 以及居群取样方式, 选取280份样本, 联合4个叶绿体片段(rbcLtrnL-FpsbA-trnHrps4), 采用最大似然法和贝叶斯法构建该属的系统发生关系, 在此基础上对凭证标本中100份材料的孢子进行观察和分析。综合分子系统学和孢粉学的研究结果, 得出结论: (1) 在形态学研究中广泛被接受的15个物种得到了单系支持, 并厘清了分类困难的复合群; (2) 发现边缘鳞盖蕨(M. marginata)可能存在隐性种; (3) 建议恢复过去归并处理为异名的瑶山鳞盖蕨(M. yaoshanica)、罗浮鳞盖蕨(M. lofoushanensis)、四川鳞盖蕨(M. szechuanica)以及滇西鳞盖蕨(M. subspeluncae); (4) 提出鳞盖蕨属可能存在杂交现象; (5) 提出鳞盖蕨属完整的属下分类建议。  相似文献   

14.
苔藓植物分子系统学研究概况   总被引:1,自引:0,他引:1  
李晶  沙伟 《植物学通报》2004,21(2):172-179
结合同工酶分析技术及随机扩增多态性DNA(RAPD)、限制性片段长度多态性(RFLP)和DNA序列测序3种分子生物学技术,对苔藓植物的分子系统学研究概况进行了介绍,并指出了在苔藓植物分子系统学研究中存在的一些问题.  相似文献   

15.
蚂蚁是分布广泛、种类和数量丰富的社会性昆虫.蚂蚁的传统分类学研究存在一定局限性,而分子生物学为蚂蚁的系统学研究提供了新途径.概述了蚂蚁分子系统学在研究内容和技术方法上的研究进展,并对今后的研究做了展望.  相似文献   

16.
The living Old World monkeys, family Cercopithecidae, are the most successful group of nonhuman primates alive today. Overall, they account for over one quarter of the extant genera of primates and approximately 40% of the species. They have an extensive fossil record extending back to the early and middle Miocene of Africa.1,2 Despite this specific diversity and a long evolutionary history, it is commonly argued that the group is relatively uniform in both its skeletal3 and dental4 anatomy, suggesting that much of the current taxonomic diversity is a relatively recent phenomenon. In such a species group, it is perhaps not surprising that the taxonomy of Old World monkeys is subject to many differing classifications. Thus, in recent years, authors have recognized as few as 10 and as many as 22 different genera within the family. Although some of this greater-than-two-fold difference in the number of genera can be attributed to the “splitting” versus “lumping” philosophies of different researchers, much of it is based on major disagreements over phylogenetic relationships. Recent studies of the genetics and chromosomes of this group have illuminated Old World monkey phylogeny in many ways. Some of these studies have resolved longstanding debates based on morphological data; others have revealed phylogenetic relationships that morphologists had never suspected.  相似文献   

17.
结合在模式产地采集的高茎紫菀(Aster procerus Hemsley)以及查阅文献资料,发现原始文献对其形态描述不充分且缺乏细胞学和分子系统学方面的报道。本研究对高茎紫菀的形态特征进行了补充描述以及核型特征和系统位置分析,为紫菀属的修订提供资料。结果表明:(1)依据观察结果,补充了高茎紫菀新的形态特征:基生叶羽状分裂,成熟的基生叶较大,长可达26 cm,宽可达8 cm;花序托圆锥状。(2)高茎紫菀的染色体数目为2n=18;核型公式为2n=2x=16 m+2 M,核型属于1 A。(3)基于ITS和ETS标记的分子系统发育树分析表明,高茎紫菀不同居群的2个个体在同一进化支上(LP=100,PP=1.00),且位于核心紫菀属(LP=100,PP=1.00),与女菀[Turczaninovia fastigiata(Fischer)Candolle]构成姐妹类群(LP=52,PP=0.99)。研究认为,高茎紫菀基生叶和花序托的特征可为紫菀属的分类提供新的证据,支持高茎紫菀位于紫菀属(Aster L.)内,建议将女菀并入紫菀属。  相似文献   

18.
The paraphyletic trilobite suborder Ptychopariina includes a large proportion of Cambrian trilobite diversity and is probably ancestral to most groups of post-Cambrian trilobites. Resolution of the phylogenetic relationships within the group is therefore crucial to a better understanding of the initial radiation of trilobites. The recognition of approaches that can successfully resolve the relationships of ptychoparioid taxa is an important first step towards this aim. Cladistic analysis was used to determine relationships within the Cambrian ptychoparioid trilobite family Conocoryphidae, and to test claims that the family is polyphyletic. Ninety-seven characters were coded for 40 conocoryphid species and nine non-conocoryphids. The results indicate that the family consists of four distantly related clades. Three are recognized here as distinct families, including an extensively revised Conocoryphidae, and the families Holocephalidae and Atopidae. The fourth clade is referred to the subfamily Acontheinae (Corynexochida) as the new Tribe Hartshillini. Analysis of the disparity of these four clades shows that they are significantly less morphologically variable than the original polyphyletic taxon, demonstrating the possible effects of taxonomic error on macroevolutionary studies of morphological disparity.  相似文献   

19.
随着PCR技术的发展以及大量DNA序列的累积,昆虫分子系统学近年来快速发展。线粒体DNA(mtDNA)序列相对于核内DNA序列进化速率较快,常被用于昆虫的系统发育研究。本文综述了国内外学者利用各种线粒体DNA序列来研究半翅目异翅亚目昆虫系统发育的研究概况。总结发现,COⅠ、COⅡ、12S rDNA、16S rDNA、Cytb、ND1、ND2和ND5等线粒体区段被用于半翅目异翅亚目系统发育的研究,其中以COI、COⅡ、16S rDNA和Cytb应用最广泛,但目前尚缺乏不同分子标记间的联合分析。进一步的研究最好在选定半翅目异翅亚目昆虫的分类阶元(如科间、亚科间、科内属间、种间或种内)后,集中测定线粒体某几个区段的DNA序列,然后进行单一分析和联合分析,并与传统形态学研究结果进行比较,可望全面分析半翅目异翅亚目昆虫的系统发育关系。  相似文献   

20.
齿蟾属(Oreolalax)为中国特有属,主要分布在我国西南地区。本文对该属的系统学研究进行了综述,包括属的建立与物种组成、地理分布特征、细胞分类学、系统发育研究历史,以及尚需研究或进一步研究的问题。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号