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1.
ITS序列的特点及其在昆虫学研究中的应用   总被引:1,自引:0,他引:1  
马婷婷  陈光  刘春香 《昆虫知识》2011,48(3):710-715
随着PCR技术和DNA测序技术的成熟及广泛应用,分子数据的分析和利用逐渐成为生物学研究的重要手段。基因组中含有丰富的遗传信息,运用核基因序列或将核基因与线粒体基因序列相结合作为遗传标记,研究昆虫的系统发育,已成为分子系统学领域的发展趋势。由于长度适中、易于扩增、进化速度快、变异性高等优点,核糖体基因中内转录间隔区(ITS)已在昆虫系统学研究中得到广泛的应用。本文介绍了ITS序列的结构特点,重点对ITS序列在近缘种及种型快速鉴定、属及属上高级阶元系统学研究、谱系生物地理学及与其它基因联合分析昆虫系统进化关系等研究中的应用及前景进行了综述。  相似文献   

2.
悬钩子属植物种类繁多,类群复杂,而且多为多倍体和杂种。该文就近年来国内外有关DNA序列在悬钩子属植物分子系统学研究中的应用现状和进展进行了综述,并对中国悬钩子属植物系统发育研究进行了展望。研究认为:叶绿体DNA序列多应用非编码区,且多与ITS序列联合分析;核基因组中ITS序列应用最为广泛,主要用于研究悬钩子属空心莓组与木莓组的进化关系、栽培品种间亲缘关系及部分杂种和多倍体的起源等;在该属植物中发现了ITS个体内多态性,但未进行ITS假基因检测,其系统学应用价值需重新评价;低拷贝核基因只有GBSSI和LEAFY有相关应用。同时认为,悬钩子属植物系统学研究中应用的DNA序列及研究类群均较少,缺乏对整个悬钩子属全面而系统的研究。指出应进一步选择具有代表性的样本、筛选合适的DNA片段,并结合形态学、孢粉学和细胞学等手段对中国悬钩子属植物系统关系进行深入研究。  相似文献   

3.
植物分子系统学近五年的研究进展概况   总被引:55,自引:3,他引:52  
本文综述了与分子系统学发展密切相关的4个因素:1.分子生物学方法的不断改进;2.基因组的全序列测定;3.用于分子系统学研究的基因种类不断增加,对这些基因进化规律的认识不断深入;4.化石DNA的研究。本文还阐述了核基因及叶绿体基因在系统学研究中的应用,例举了rbcL、matk、18s rDNA和ITS序列分析在植物系统发育研究中取得的重要成果,同时提出了分子系统学研究中应注意的一些问题。  相似文献   

4.
核糖体rDNA ITS是被子植物系统发育研究中应用最广泛的分子标记之一。以前人们认为同一物种中的ITS序列因致同进化而使不同拷贝高度一致,在分子系统学研究中常以ITS1-5.8S-ITS2序列作为构建系统进化树的基础。近年来,在对一些被子植物的研究中发现这段序列在同一物种中具有多态性,有些拷贝中的5.8S区不具编码功能,人们把含有不具编码功能5.8S区的ITS1-5.8S-ITS2序列定义为ITS假基因序列,它对同源基因致同进化的假设形成了新的挑战。在诸多应用ITS序列重建系统进化关系的研究中,栎属系统学研究因ITS假基因的发现而倍受关注。本文以栎属为例回顾了ITS假基因的发现过程,分析了其对该属系统学研究的影响,为分子生物学在植物系统进化研究中的应用提供一些新的参考。  相似文献   

5.
李晶  沙伟 《植物学报》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   

6.
核糖体rDNA ITS序列在真菌学研究中的应用   总被引:27,自引:0,他引:27  
匡治州  许杨 《生命的化学》2004,24(2):120-122
rDNA序列的同源性和变化性使其用于真菌各级水平的系统学研究,其中ITS区进化速率较快、长度适中,广泛用于属内种间或种内群体的系统学研究。该文就rDNA序列结构特点、ITS序列在真菌分子系统学及病原学中的应用等方面进行综述。  相似文献   

7.
核糖体rDNA ITS 是被子植物系统发育研究中应用最广泛的分子标记之一。以前人们认为同一物种
中的ITS 序列因致同进化而使不同拷贝高度一致, 在分子系统学研究中常以ITS1- 518S- ITS2 序列作为构建
系统进化树的基础。近年来, 在对一些被子植物的研究中发现这段序列在同一物种中具有多态性, 有些拷
贝中的518S 区不具编码功能, 人们把含有不具编码功能518S 区的ITS1-51 8S- ITS2 序列定义为ITS 假基因序
列, 它对同源基因致同进化的假设形成了新的挑战。在诸多应用ITS 序列重建系统进化关系的研究中, 栎
属系统学研究因ITS 假基因的发现而倍受关注。本文以栎属为例回顾了ITS 假基因的发现过程, 分析了其
对该属系统学研究的影响, 为分子生物学在植物系统进化研究中的应用提供一些新的参考。  相似文献   

8.
DNA序列在植物系统学研究中的应用   总被引:68,自引:6,他引:62  
植物DNA序列由于进化速率上的差异而适用于不同分类阶元的系统发育研究,因此,针对某一特定的系统学问题选择相应合适的分子片段是分子系统学研究中最为关键的一步。在前人研究的基础上,主要讨论了目前分子系统发育和进化研究中一些常用的DNA序列的适用范围,包括nrDNA的18S基因及ITS等非编码区,cpDNA的编码基因(rbcI、matK、ndhF、atpB)及非编码区序列(rpL16、rpoC1、rps16、trnL-F和trnT-L)和应用较少的mtDNA。研究表明,18S、rbcI等编码基因及mtDNA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及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   

9.
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   

10.
DNA是遗传信息的载体,直接对DNA核苷酸排列顺序的分析和比较是研究苔藓分子系统学的最彻底和最理想的方法。本文综述了DNA序列(叶绿体基因组、核基因组和线粒体基因组)在苔藓分子系统学中的应用,探讨了基因片段的选择策略。并提出只有将分子数据和传统分类学取得的研究成果结合起来,构建最合理的系统树,才能更好地推动苔藓分子系统学的发展。  相似文献   

11.
Length and guanine–cytosine (GC) content of the ribosomal first internal transcribed spacer (ITS1) were compared across a wide variety of marine animal species, and its phylogenetic utility was investigated. From a total of 773 individuals representing 599 species, we only failed to amplify the ITS1 sequence from 87 individuals by polymerase chain reaction with universal ITS1 primers. No species was found to have an ITS1 region shorter than 100 bp. In general, the ITS1 sequences of vertebrates were longer (318 to 2,318 bp) and richer in GC content (56.8% to 78%) than those of invertebrates (117 to 1,613 bp and 35.8% to 71.3%, respectively). Specifically, gelatinous animals (Cnidaria and Ctenophora) were observed to have short ITS1 sequences (118 to 422 bp) with lower GC content (35.8% to 61.7%) than the other animal taxa. Mollusca and Crustacea were diverse groups with respect to ITS1 length, ranging from 108 to 1,118 and 182 to 1,613 bp, respectively. No universal relationship between length and GC content was observed. Our data indicated that ITS1 has a limited utility for phylogenetic analysis as obtaining confident sequence alignment was often impossible between different genera of the same family and even between congeneric species.  相似文献   

12.
刘超洋  郭守玉 《菌物学报》2009,28(5):705-711
本研究以松萝属为研究对象,构建了该属核糖体5.8S和第二转录区间(ITS2)的二级结构模型,并对种间的结构差异进行了比较。结果显示,松萝属的结构与先前发表的真核生物ITS2二级结构模型非常相似。属内种间的结构差异主要集中在第二转录区间的臂上。核酸序列分析所产生的系统树与结构特征的比较结果相一致,表明ITS2的二级结构信息可以作为一种辅助的分类手段,适用于松萝属的种的鉴定和亲缘关系研究。  相似文献   

13.
Cortinarius is the most species rich genus of mushroom forming fungi with an estimated 2000 spp. worldwide. However, species delimitation within the genus is often controversial. This is particularly true in the section Calochroi (incl. section Fulvi), where the number of accepted taxa in Europe ranges between c.60 and c.170 according to different taxonomic schools. Here, we evaluated species delimitation within this taxonomically difficult group of species and estimated their phylogenetic relationships. Species were delimited by phylogenetic inference and by comparison of ITS sequence data in combination with morphological characters. A total of 421 ITS sequences were analyzed, including data from 53 type specimens. The phylogenetic relationships of the identified species were estimated by analyzing ITS data in combination with sequence data from the two largest subunits of RNA polymerase II (RPB1 and RPB2). Seventy-nine species were identified, which are believed to constitute the bulk of the diversity of this group in Europe. The delimitation of species based on ITS sequences is more consistent with a conservative morphological species concept for most groups. ITS sequence data from 30 of the 53 types were identical to other taxa, and most of these can be readily treated as synonyms. This emphasizes the importance of critical analysis of collections before describing new taxa. The phylogenetic separation of species was, in general, unambiguous and there is considerable potential for using ITS sequence data as a barcode for the group. A high level of homoplasy and phenotypic plasticity was observed for morphological and ecological characters. Whereas most species and several minor lineages can be recognized by morphological and ecological character states, these same states are poor indicators at higher levels.  相似文献   

14.
衣藻属的系统发育分析——基于形态形状和nrDNA ITS序列   总被引:1,自引:0,他引:1  
通过实验分析莱茵衣藻 ( Chlamydomonas reinhardtii) 1个种和互连网获得衣藻属 1 5个种及丝藻属 1个种 ( Ulothrix zonata) ,共 1 7个种的 nr DNA ITS序列 ,并以 U.zonata为外类群 ,采用计算机分析软件包对其进行分析及构建分子系统发育树图。同时以 1 2个传统分类性状 ,对此 1 6种衣藻构建数据矩阵 ;以 U.zonata动孢子的相应性状为外类群原始性状 ,用Wagner法在计算机上对其进行分枝分析 ;然后比较并分析分子系统树和表征性状分支分析树的异同。初步尝试以 ITS分子序列系统发育分析作为传统性状分析的补充来研究衣藻种间的亲缘关系。  相似文献   

15.
Wolinska J  King KC  Vigneux F  Lively CM 《Parasitology》2008,135(14):1667-1678
We describe the infectivity, virulence, cultivating conditions, and phylogenetic positions of naturally occurring oomycete parasites of Daphnia, invertebrates which play a major role in aquatic food webs. Daphnia pulex individuals were found dead and covered by oomycete mycelia when exposed to pond sediments. We were able to extract 4 oomycete isolates from dead Daphnia and successfully cultivate them. Using the ITS and LSU rDNA sequences, we further showed these isolates to be distinct species. The isolates were experimentally demonstrated to be parasitic and not saprobic. After exposure to the parasites, Daphnia mortality was much higher than that reported for Daphnia infected with other known parasite species. Therefore, it is likely that oomycete parasites are important selective pressures in natural Daphnia populations. Moreover, their close phylogenetic relationship to parasites of fish and algae suggests that the stability of aquatic food webs (i.e. fish-Daphnia-algae) might be influenced by the shared parasite communities.  相似文献   

16.
基于形态特征和ITS序列对7个鹅膏菌属菌株的分类鉴定   总被引:7,自引:0,他引:7  
以采自浙江省丽水地区的7个鹅膏菌属菌株作为研究材料,在基于形态特征进行初步鉴定的基础上,对7种鹅膏菌的rDNAITS区段进行克隆测序和序列特征比较分析。进一步对ITS序列进行核酸序列数据库GenBank同源性检索比对,将从GenBank检索获得的9个最相似物种的ITS序列连同7种鹅膏菌的ITS序列一起作系统发育分析。结果表明:基于ITS序列对f6、f9和f493个菌株的分子鉴定支持了基于形态特征的鉴定结果,对f5的分子鉴定不支持形态鉴定的结果,f8为鹅膏菌属内某种,f66为鹅膏菌属内某种,并与Amanitafulva,A.atrofusca,A.orientifulva3种鹅膏菌的亲缘关系较近,f7与另外6种鹅膏菌的亲缘关系相差甚远。研究结果提示基于分子水平上的ITS序列分析不能单方面作为大型真菌分类鉴定的可靠依据,可以作为基于传统形态学分类鉴定的辅助参考依据。  相似文献   

17.
基于ITS序列探讨忍冬属的系统发育关系   总被引:2,自引:0,他引:2  
以七子花(Heptacodium miconioides)为外类群,运用MEGA软件对20种忍冬属植物进行系统发育分析,采用邻接法(NJ)和最大简约法(MP)构建系统发育树,从分子系统学角度探讨忍冬属下的亲缘关系.结果表明:(1)在NJ和MP系统树中,没有形成系统树的基部分支,忍冬亚属(Subg.Chamaecerasus)和轮花亚属(Subg.Lonicera)没有形成姐妹群关系.(2)在各系统树中,囊管组内的各种没有聚为一支,故认为对囊管组的划分应进一步探讨.(3)忍冬属ITS区(ITS1+ITS2)的信息位点达到11.0%,信息位点比较丰富,证明ITS序列可以为解决忍冬属植物的系统发育问题提供较强的证据.  相似文献   

18.
The unavailability of the reproductive structure and unpredictability of vegetative characters for the identification and phylogenetic study of bamboo prompted the application of molecular techniques for greater resolution and consensus. We first employed internal transcribed spacer (ITS1, 5.8S rRNA and ITS2) sequences to construct the phylogenetic tree of 21 tropical bamboo species. While the sequence alone could grossly reconstruct the traditional phylogeny amongst the 21-tropical species studied, some anomalies were encountered that prompted a further refinement of the phylogenetic analyses. Therefore, we integrated the secondary structure of the ITS sequences to derive individual sequence-structure matrix to gain more resolution on the phylogenetic reconstruction. The results showed that ITS sequence-structure is the reliable alternative to the conventional phenotypic method for the identification of bamboo species. The best-fit topology obtained by the sequence-structure based phylogeny over the sole sequence based one underscores closer clustering of all the studied Bambusa species (Sub-tribe Bambusinae), while Melocanna baccifera, which belongs to Sub-Tribe Melocanneae, disjointedly clustered as an out-group within the consensus phylogenetic tree. In this study, we demonstrated the dependability of the combined (ITS sequence+structure-based) approach over the only sequence-based analysis for phylogenetic relationship assessment of bamboo.  相似文献   

19.
Conventional classification of the species in the family Mycoplasmataceae is mainly based on phenotypic criteria, which are complicated, can be difficult to measure, and have the potential to be hampered by phenotypic deviations among the isolates. The number of biochemical reactions suitable for phenotypic characterization of the Mycoplasmataceae is also very limited and therefore the strategy for the final identification of the Mycoplasmataceae species is based on comparative serological results. However, serological testing of the Mycoplasmataceae species requires a performance panel of hyperimmune sera which contains anti-serum to each known species of the family, a high level of technical expertise, and can only be properly performed by mycoplasma-reference laboratories. In addition, the existence of uncultivated and fastidious Mycoplasmataceae species/isolates in clinical materials significantly complicates, or even makes impossible, the application of conventional bacteriological tests. The analysis of available genetic markers is an additional approach for the primary identification and phylogenetic classification of cultivable species and uncultivable or fastidious organisms in standard microbiological laboratories. The partial nucleotide sequences of the RNA polymerase β-subunit gene (rpoB) and the 16S-23S rRNA intergenic transcribed spacer (ITS) were determined for all known type strains and the available non-type strains of the Mycoplasmataceae species. In addition to the available 16S rRNA gene data, the ITS and rpoB sequences were used to infer phylogenetic relationships among these species and to enable identification of the Mycoplasmataceae isolates to the species level. The comparison of the ITS and rpoB phylogenetic trees with the 16S rRNA reference phylogenetic tree revealed a similar clustering patterns for the Mycoplasmataceae species, with minor discrepancies for a few species that demonstrated higher divergence of their ITS and rpoB in comparison to their neighbor species. Overall, our results demonstrated that the ITS and rpoB gene could be useful complementary phylogenetic markers to infer phylogenetic relationships among the Mycoplasmataceae species and provide useful background information for the choice of appropriate metabolic and serological tests for the final classification of isolates. In summary, three-target sequence analysis, which includes the ITS, rpoB, and 16S rRNA genes, was demonstrated to be a reliable and useful taxonomic tool for the species differentiation within the family Mycoplasmataceae based on their phylogenetic relatedness and pairwise sequence similarities. We believe that this approach might also become a valuable tool for routine analysis and primary identification of new isolates in medical and veterinary microbiological laboratories.  相似文献   

20.
测定了簇毛黄耆亚属(Pogonophace)4组8种和外类群Caragana roborovskyi的ITS序列,从GenBank中调出相关12属47种的ITS序列,组成数据距阵,应用PAUP程序中的最大简约法构建了系统发育树状图。扁荚组(Sect.Sesbanella)与亚属其余类群在系统树上处于不同的分支,亲缘关系较远这个亚属不是一个单系类群;膨果组(Sect.Bibracteola)。背扁组(Sect.Phyllolobium)和袋果组(Sect.Trichostylus)作为一个单系类群能得到ITS序列的支持,但与分组以及膨果组下系的划分都得不到ITS序列分析的支持。  相似文献   

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