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1.
A capillary gel electrophoretic (CGE) method for the quantitative analysis of RuBisCo in spinach leaves was developed. RuBisCo was resolved into large and small subunits in the presence of sodium dodecyl sulphate (SDS) by the CGE procedure which enabled the determination of the molecular weight of each unit accurately; the values so determined were in close agreement with those reported using other methods. Advantages of CGE over SDS-polyacrylamide gel electrophoresis and high-pressure gel filtration include decreased sample preparation and analysis time, superior resolution and greater sensitivity permitting reduced sample size and trace analysis. In addition, CGE provided precise quantification of RuBisCo and was demonstrated to be a viable alternative to other available methods of protein analysis.  相似文献   

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Summary In cryptomonads, unicellular phototrophic flagellates, the plastid(s) is (are) located in a special narrow compartment which is bordered by two membranes; it harbours neither mitochondria nor Golgi dictyosomes but comprises eukaryotic ribosomes and starch grains together with a small organelle called the nucleomorph. The nucleomorph contains DNA and is surrounded by a double membrane with pores. It is thought to be the vestigial nucleus of a phototrophic eukaryotic endosymbiont. Cryptomonads are therefore supposed to represent an intermediate state in the evolution of complex plastids from endosymbionts. We have succeeded in isolating pure nucleomorph fractions, and can thus provide, using pulsed field gel electrophoresis, polymerase chain reaction and sequence analysis, definitive proof for the eukaryotic nature of the symbiont and its phylogenetic origin.  相似文献   

5.
A detailed phylogeny for the Methanomicrobiales   总被引:1,自引:0,他引:1  
The small subunit rRNA sequence of twenty archaea, members of the Methanomicrobiales, permits a detailed phylogenetic tree to be inferred for the group. The tree confirms earlier studies, based on far fewer sequences, in showing the group to be divided into two major clusters, temporarily designated the "methanosarcina" group and the "methanogenium" group. The tree also defines phylogenetic relationships within these two groups, which in some cases do not agree with the phylogenetic relationships implied by current taxonomic names--a problem most acute for the genus Methanogenium and its relatives. The present phylogenetic characterization provides the basis for a consistent taxonomic restructuring of this major methanogenic taxon.  相似文献   

6.
The sequence of subfamilies,Cinchonoideae, Antirheoideae andRubioideae, attemps to show their natural affinities and phylogeny. The subfamilies are those ofVerdcourt, and the order in which they are presented is that ofBremekamp. A list is presented of the subfamilies, tribes and genera of theRubiaceae to be utilized in the Catálogo Ilustrado de las plantas de Cundinamarca, Colombia.  相似文献   

7.
A phylogenomic approach was used to generate an amino acid phylogeny for 12 whole genomes representing 10 species in the family Pasteurellaceae. Orthology of genes was determined using an approach similar to OrthologID (http://nypg.bio.nyu.edu/orthologid/about.html) and resulted in the generation of a matrix with 3130 genes with 1,194,615 aligned amino acid characters of which 239,504 characters are phylogenetically informative. Phylogenetic analysis of the concatenated matrix using all standard approaches (maximum parsimony, maximum likelihood, and Bayesian analysis) results in a single extremely robust phylogenetic hypothesis for the species examined in this study. Remarkably, no single gene partition gives the same tree as the concatenated analysis. By analyzing partitioned support in the data matrix, we show that there is very little negative support emanating from individual gene partitions to suggest that the concatenated hypothesis is not tenable. The large number of characters in the matrix allows us to test hypotheses concerning missing data and character number in phylogenomic studies, and we conclude that matrices constructed using genome level information are very robust to missing data. We show that a very large number of concatenated gene sequences (>160) are needed to reliably obtain the same topology as the overall analysis.  相似文献   

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The ascomycete order Diaporthales is reviewed based on recent phylogenetic data that outline the families and integrate related asexual fungi. The order now consists of nine families, one of which is newly recognized as Schizoparmeaceae fam. nov., and two families are recircumscribed. Schizoparmeaceae fam. nov., based on the genus Schizoparme with its anamorphic state Pilidella and including the related Coniella, is distinguished by the three-layered ascomatal wall and the basal pad from which the conidiogenous cells originate. Pseudovalsaceae is recognized in a restricted sense, and Sydowiellaceae is circumscribed more broadly than originally conceived. Many species in the Diaporthales are saprobes, although some are pathogenic on woody plants such as Cryphonectria parasitica, the cause of chestnut blight, and agricultural crops such as canker diseases of soybean and sunflower caused by species of Diaporthe-Phomopsis in both temperate and tropical regions. Members of the Diaporthales such as Apiognomonia-Discula and Diaporthe-Phomopsis are commonly encountered as endophytes of woody plants.  相似文献   

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The Asteraceae are commonly divided into two large subfamilies, the Cichorioideae (syn. Lactucoideae; Mutisieae, Cardueae, Lactuceae, Vernonieae, Liabeae, Arctoteae) and the Asteroideae (Inuleae, Astereae, Anthemideae, Senecioneae, Calenduleae, Heliantheae, Eupatorieae). Recent phylogenetic analyses based on morphological and chloroplast DNA data conclusively show that the Mutisieae-Barnadesiinae are the sister group to the rest of the family and that the Asteroideae tribes form a monophyletic group. The Vernonieae and Liabeae are sister tribes and the Eupatorieae are nested within a paraphyletic Heliantheae; otherwise tribal interrelationships are still largely uncertain. The Mutisieae-Barnadesiinae are excluded from the Mutisieae and elevated to the new subfamily Barnadesioideae. The two subfamilies Barnadesioideae and Asteroideae are monophyletic, whereas the status of the Cichorioideae remains uncertain. Analyses of chloroplast DNA data support the monophyly of the Cichorioideae; however, morphological data indicate that the subfamily is paraphyletic. Further studies are needed to test the monophyly of the Cichorioideae, as well as to further resolve tribal interrelationships in the two larger subfamilies.  相似文献   

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A review of lower actinopterygian phylogeny has led us to the conclusion that the Cladistia are the sister group of Recent actinopterygians (Actinopteri) and that the extinct Palaeonisciformes are a paraphyletic group, comprising stem-group actinopterygians (e.g. Cheirolepis ), stem-group actinopterans (e.g. Moythomasia ) and relatives of higher actinopterans such as Pteronisculus . Our analysis further concluded that the Acipenseriformes formed a clade together with Saurichthys and Birgeria , which was most parsimoniously resolved when the Acipenseriformes and Saurichthys were sister groups.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 511−525.  相似文献   

12.
Myzostomids are minute, soft-bodied, marine worms associated with echinoderms since the Carboniferous. Due to their long history as host-specific symbionts, they have acquired a highly derived body plan that obscures their phylogenetic affinities to other metazoans. Because certain organs are serially arranged a closer relationship between polychaetes and myzostomids has repeatedly been discussion. We presented here a review on the ultrastructure of myzostomids with the most recent analyses that concern their phylogenetic position. The ultrastructure of the integument, digestive system, excretory system and nervous system are summarized. Unpublished information on the gametogenesis and reproductive systems of myzostomids are also exposed with a view on their reproductive process.  相似文献   

13.
A molecular phylogeny of annelids   总被引:6,自引:0,他引:6  
We present parsimony analyses of annelids based on the largest taxon sample and most extensive molecular data set yet assembled, with two nuclear ribosomal genes (18S rDNA and the D1 region of 28S rDNA), one nuclear protein coding‐gene (Histone H3) and one mitochondrial ribosomal gene (16S rDNA) from 217 terminal taxa. Of these, 267 sequences are newly sequenced, and the remaining were obtained from GenBank. The included taxa are based on the criteria that the taxon must have 18S rDNA or at least two other loci. Our analyses show that 68% of annelid family ranked taxa represented by more than one taxon in our study are supported by a jackknife value > 50%. In spite of the size of our data set, the phylogenetic signal in the deepest part of the tree remains weak and the majority of the currently recognized major polychaete clades (except Amphinomida and Aphroditiformia) could not be recovered. Terbelliformia is monophyletic (with the exclusion of Pectinariidae, for which only 18S data were available), whereas members of taxa such as Phyllodocida, Cirratuliformia, Sabellida and Scolecida are scattered over the trees. Clitellata is monophyletic, although Dinophilidae should possibly be included, and Clitellata has a sister group within the polychaetes. One major problem is the current lack of knowledge on the closest relatives to annelids and the position of the annelid root. We suggest that the poor resolution in the basal parts of the trees presented here may be due to lack of signal connected to incomplete data sets both in terms of terminal and gene sampling, rapid radiation events and/or uneven evolutionary rates and long‐branch attraction. © The Willi Hennig Society 2006.  相似文献   

14.
Pezizomycotina is the largest subphylum of Ascomycota and includes the vast majority of filamentous, ascoma-producing species. Here we report the results from weighted parsimony, maximum likelihood and Bayesian phylogenetic analyses of five nuclear loci (SSU rDNA, LSU rDNA, RPB1, RPB2 and EF-lalpha) from 191 taxa. Nine of the 10 Pezizomycotina classes currently recognized were represented in the sampling. These data strongly supported the monophyly of Pezizomycotina, Arthoniomycetes, Eurotiomycetes, Orbiliomycetes and Sordariomycetes. Pezizomycetes and Dothideomycetes also were resolved as monophyletic but not strongly supported by the data. Lecanoromycetes was resolved as paraphyletic in parsimony analyses but monophyletic in maximum likelihood and Bayesian analyses. Leotiomycetes was polyphyletic due to exclusion of Geoglossaceae. The two most basal classes of Pezizomycotina were Orbiliomycetes and Pezizomycetes, both of which comprise species that produce apothecial ascomata. The seven remaining classes formed a monophyletic group that corresponds to Leotiomyceta. Within Leotiomyceta, the supraclass clades of Leotiomycetes s.s. plus Sordariomycetes and Arthoniomycetes plus Dothideomycetes were resolved with moderate support.  相似文献   

15.
We present the most comprehensive molecular phylogeny of bryozoans to date. Our concatenated alignment of two nuclear ribosomal and five mitochondrial genes includes 95 taxa and 13,292 nucleotide sites, of which 8297 were included. The number of new sequences generated during this project are for each gene:ssrDNA (32), lsrDNA (22), rrnL (38), rrnS (35), cox1 (37), cox3 (34), and cytb (44). Our multi-gene analysis provides a largely stable topology across the phylum. The major groups were unambiguously resolved as (Phylactolaemata (Cyclostomata (Ctenostomata, Cheilostomata))), with Ctenostomata paraphyletic. Within Phylactolaemata, (Stephanellidae, Lophopodidae) form the earliest divergent clade. Fredericellidae is not resolved as a monophyletic family and forms a clade together with Plumatellidae, Cristatellidae and Pectinatellidae, with the latter two as sister taxa. Hyalinella and Gelatinella nest within the genus Plumatella. Cyclostome taxa fall into three major clades: i. (Favosipora (Plagioecia, Rectangulata)); ii. (Entalophoroecia ((Diplosolen, Cardioecia) (Frondipora, Cancellata))); and iii. (Articulata ((Annectocyma, Heteroporidae) (Tubulipora (Tennysonia, Idmidronea)))), with suborders Tubuliporina and Cerioporina, and family Plagioeciidae each being polyphyletic. Ctenostomata is composed of three paraphyletic clades to the inclusion of Cheilostomata: ((Alcyonidium, Flustrellidra) (Paludicella (Anguinella, Triticella)) (Hislopia (Bowerbankia, Amathia)) Cheilostomata); Flustrellidra nests within the genus Alcyonidium, and Amathia nests within the genus Bowerbankia. Suborders Carnosa and Stolonifera are not monophyletic. Within the cheilostomes, Malacostega is paraphyletic to the inclusion of all other cheilostomes. Conopeum is the most early divergent cheilostome, forming the sister group to ((Malacostega, Scrupariina, Inovicellina) ((Hippothoomorpha, Flustrina) (Lepraliomorpha, Umbonulomorpha))); Flustrina is paraphyletic to the inclusion of the hippothoomorphs; neither Lepraliomorpha nor Umbonulomorpha is monophyletic. Ascophorans are polyphyletic, with hippothoomorphs grouping separately from lepraliomorphs and umbonulomorphs; no cribrimorphs were included in the analysis. Results are discussed in the light of molecular and morphological evidence. Ancestral state reconstruction of larval strategy in Gymnolaemata revealed planktotrophy and lecithotrophy as equally parsimonious solutions for the ancestral condition. More comprehensive taxon sampling is expected to clarify this result. We discuss the extent of non-bryozoan contaminant sequences deposited in GenBank and their impact on the reconstruction of metazoan phylogenies and those of bryozoan interrelationships.  相似文献   

16.
Bignoniaceae are woody, trees, shrubs, and lianas found in all tropical floras of the world with lesser representation in temperate regions. Phylogenetic analyses of chloroplast sequences (rbcL, ndhF, trnL-F) were undertaken to infer evolutionary relationships in Bignoniaceae and to revise its classification. Eight clades are recognized as tribes (Bignonieae, Catalpeae, Coleeae, Crescentieae, Jacarandeae, Oroxyleae, Tecomeae, Tourrettieae); additional inclusive clades are named informally. Jacarandeae and Catalpeae are resurrected; the former is sister to the rest of the family, and the latter occupies an unresolved position within the "core" Bignoniaceae. Tribe Eccremocarpeae is included in Tourrettieae. Past classifications recognized a large Tecomeae, but this tribe is paraphyletic with respect to all other tribes. Here Tecomeae are reduced to a clade of approximately 12 genera with a worldwide distribution in both temperate and tropical ecosystems. Two large clades, Bignonieae and Crescentiina, account for over 80% of the species in the family. Coleeae and Crescentieae are each included in larger clades, the Paleotropical alliance and Tabebuia alliance, respectively; each alliance includes a grade of taxa assigned to the traditional Tecomeae. Parsimony inference suggests that the family originated in the neotropics, with at least five dispersal events leading to the Old World representatives.  相似文献   

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? Premise of the study: Verbenaceae consist of trees, shrubs, lianas, and herbs distributed primarily in Latin America, where they occur in a wide array of ecosystems. A second center of diversity exists in Africa. Competing morphology-based classifications that rely on different traits conflict in significant ways. A broad phylogenetic study was undertaken to assess those classifications and to examine the historical geography of the family. ? Methods: Analysis of seven chloroplast DNA regions for 109 species, representing all genera except one monotypic genus, provide inference into evolutionary relationships in Verbenaceae. ? Key results: The phylogeny shows that none of the traditional classifications reflect phylogenetic relationships very well. Eight clades are recognized as tribes (Casselieae, Citharexyleae, Duranteae, Lantaneae, Neospartoneae trib. nov., Petreeae, Priveae, and Verbeneae). Two genera, Dipyrena and Rhaphithamnus, remain unplaced in these larger clades. Petreeae, which consist of Neotropical lianas, are sister to the rest of the family. Lantaneae and Verbeneae together form a derived clade that comprises approximately two-thirds of the species in Verbenaceae. ? Conclusions: We present a new tribal classification, including one new tribe, Neospartoneae trib. nov., to accommodate three small genera of Argentine species (Diostea, Neosparton, and Lampaya). Phylogenetic inference suggests a South American origin for Verbenaceae, with approximately six colonization events having given rise to the Old World species.  相似文献   

18.
跳虫系统进化的研究进展   总被引:1,自引:0,他引:1  
熊燕  栾云霞 《生命科学》2007,19(2):239-244
跳虫是弹尾纲(Collembola)的俗称,在所有六足动物中化石年代最早,因此跳虫是六足动物起源及进化研究中非常重要的类群。跳虫的起源、分类地位和系统关系等问题,对于阐明六足动物甚至节肢动物各大类群的系统关系非常关键,日益成为相关学者关注和争论的焦点。本文就跳虫形态学和分子系统学方面的研究工作进行了综述。  相似文献   

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F W Spiegel 《Bio Systems》1991,25(1-2):113-120
The flagellated members of the group of mycetozoans known as protostelids have been recognized for some time to be members of a monophyletic group which also includes the myxomycetes. This inference was based primarily upon comparisons of the flagellar apparatus of the amoeboflagellate state. However, more detailed comparisons based on the whole life history and comparisons with an outgroup were necessary to have information sufficient to determine the interrelationships within the group. Recent studies of the other states of the life history of protostelids have provided a wealth of additional morphological and developmental characters such that an in depth phylogenetic analysis is possible. The results show that the group can be resolved into two major clades, one of which contains the myxomycetes and the myxomycete-like protostelid genera, Protosporangium, Clastostelium, and Ceratiomyxa, and another which contains the protostelid genera Planoprotostelium, Cavostelium, and Ceratiomyxella. As the myxomycetes appear to be part of the ingroup, and not a sister group to the protostelids, L.S. Olive's subclass Protostelia must be considered paraphyletic.  相似文献   

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