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1.
New Phytol ; 240(5): 2137-2150, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37697646

RESUMO

Divergence times based on molecular clock analyses often differ from those derived from total-evidence dating (TED) approaches. For bryophytes, fossils have been excluded from previous assessments of divergence times, and thus, their utility in dating analyses remains unexplored. Here, we conduct the first TED analyses of the complex thalloid liverworts (Marchantiopsida) that include fossils and evaluate macroevolutionary trends in morphological 'diversity' (disparity) and rates. Phylogenetic analyses were performed on a combined dataset of 130 discrete characters and 11 molecular markers (sampled from nuclear, plastid and mitochondrial genomes). Taxon sampling spanned 56 extant species - representing all the orders within Marchantiophyta and extant genera within Marchantiales - and eight fossil taxa. Total-evidence dating analyses support the radiation of Marchantiopsida during Late Silurian-Early Devonian (or Middle Ordovician when the outgroup is excluded) and that of Ricciaceae in the Middle Jurassic. Morphological change rate was high early in the history of the group, but it barely increased after Late Cretaceous. Disparity-through-time analyses support a fast increase in diversity until the Middle Triassic (c. 250 Ma), after which phenotypic evolution slows down considerably. Incorporating fossils in analyses challenges previous assumptions on the affinities of extinct taxa and indicates that complex thalloid liverworts radiated c. 125 Ma earlier than previously inferred.


Assuntos
Briófitas , Hepatófitas , Filogenia , Hepatófitas/genética , Fósseis , Plastídeos/genética , Evolução Biológica
2.
J Exp Bot ; 73(13): 4273-4290, 2022 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-35394022

RESUMO

Systematics reconstructs tempo and mode in biological evolution by resolving the phylogenetic fabric of biodiversity. The staggering duration and complexity of evolution, coupled with loss of information (extinction), render exhaustive reconstruction of the evolutionary history of life unattainable. Instead, we sample its products-phenotypes and genotypes-to generate phylogenetic hypotheses, which we sequentially reassess and update against new data. Current consensus in evolutionary biology emphasizes fossil integration in total-evidence analyses, requiring in-depth understanding of fossils-age, phenotypes, and systematic affinities-and a detailed morphological framework uniting fossil and extant taxa. Bryophytes present a special case: deep evolutionary history but sparse fossil record and phenotypic diversity encompassing small dimensional scales. We review how these peculiarities shape fossil inclusion in bryophyte systematics. Paucity of the bryophyte fossil record, driven primarily by phenotypic (small plant size) and ecological constraints (patchy substrate-hugging populations), and incomplete exploration, results in many morphologically isolated, taxonomically ambiguous fossil taxa. Nevertheless, instances of exquisite preservation and pioneering studies demonstrate the feasibility of including bryophyte fossils in evolutionary inference. Further progress will arise from developing extensive morphological matrices for bryophytes, continued exploration of the fossil record, re-evaluation of previously described fossils, and training specialists in identification and characterization of bryophyte fossils, and in bryophyte morphology.


Assuntos
Briófitas , Fósseis , Biodiversidade , Evolução Biológica , Briófitas/genética , Filogenia
3.
Cladistics ; 37(3): 231-247, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34478198

RESUMO

In recent years, the use of extensive molecular and morphological datasets has clarified the phylogenetic relationships among the orders of complex thalloid liverworts (Marchantiidae). However, previous studies excluded extinct taxa; thereby, undersampling the actual taxonomic diversity of the group. Here, we conducted a total-evidence analysis of Marchantiidae incorporating fossils. The combined dataset consisted of 11 genes-sampled from the nuclear, mitochondrial and plastid genomes-and 128 morphological characters. Sixty-two species, representing all classes and orders within Marchantiophyta and genera within Marchantiidae were included in the analyses. Six fossils were scored from literature: two assigned to the outgroup (Metzgeriothallus sharonae and Pallaviciniites sandaolingensis) and four to the ingroup (Marchantites cyathodoides, M. huolinhensis, Ricciopsis ferganica and R. sandaolingensis). Tree searches were conducted using parsimony as the optimality criterion. Clade sensitivity was assessed across a wide range of weighting regimes. Also, we evaluated the influence of fossils on the inferred topologies and branch support. Our results were congruent with previously inferred clades above the order level: Neohodgsoniales was sister to a clade formed by Sphaerocarpales and Marchantiales. However, relationships among families within Marchantiales contradicted recent studies. For instance, a clade consisting of Monosoleniaceae, Wiesnerellaceae and Targioniaceae was sister to the morphologically simple taxa instead of being nested within them as in previous studies. Novel synapomorphies were found for several clades within Marchantiales. Outgroup fossils were more influential than Marchantiidae fossils on overall topologies and branch support values. Except for a single weighting scheme, sampling continuous characters and down-weighting characters improved fossil stability. Ultimately, our results challenge the widespread notion that bryophyte fossils are problematic for phylogenetic inference.


Assuntos
Biodiversidade , Fósseis , Genoma de Planta , Genomas de Plastídeos , Hepatófitas/fisiologia , Filogenia , Hepatófitas/classificação , Hepatófitas/genética , Humanos
4.
J Plant Res ; 134(1): 55-76, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33251557

RESUMO

Microsoroideae is the third largest of the six subfamilies of Polypodiaceae, containing over 180 species. These ferns are widely distributed in the tropical and subtropical regions of the Old World and Oceania. We documented the spore ornamentation and integrated these data into the latest phylogenetic hypotheses, including a sampling of 100 taxa representing each of 17 major lineages of microsoroid ferns. This enabled us to reconstruct the ancestral states of the spore morphology. The results show verrucate ornamentation as an ancestral state for Goniophlebieae and Lecanoptereae, globular for Microsoreae, and rugulate surface for Lepisoreae. In addition, spore ornamentation can be used to distinguish certain clades of the microsoroid ferns. Among all five tribes, Lecanoptereae show most diversity in spore surface ornamentation.


Assuntos
Gleiquênias , Polypodiaceae , Gleiquênias/genética , Filogenia , Esporos
5.
Mol Phylogenet Evol ; 143: 106665, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31704235

RESUMO

The microsoroid ferns are one of the largest subfamilies of the Polypodiaceae with over 180 species mainly found in the humid forests of tropical Australasia. The phylogenetic relationships are still unclear, especially the delimitation of the genus Microsorum which has been recognized to be non-monophyletic. We analysed the microsoroid ferns using six chloroplast DNA regions (rbcL, rps4+rps4-trnS, trnL+trnL-trnF, atpA, atpB and matK) in order to present a robust hypothesis of their phylogeny. Our results suggest that they comprise up to 17 genera; of them, 12 agree with a previously accepted generic classification. Five tribes are proposed based on the phylogenetic relationships. Most of the species traditionally included in the genus Microsorum are found in six genera belonging to two tribes. In addition to the commonly used DNA markers, the additional atpA and matK are helpful to provide information about the phylogenetic relationships of the microsoroid ferns.


Assuntos
DNA de Cloroplastos , Polypodiaceae/classificação , Marcadores Genéticos , Filogenia , Polypodiaceae/genética
6.
Mol Phylogenet Evol ; 143: 106662, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31676419

RESUMO

Morphological data has gained renewed attention and has been shown to be crucial in clarifying the phylogenetic relationship in a wide range of taxa. In the last decades, phylogenetic analyses of sequence-level data have radically modified the systematic schemes within bryophytes (early non-vascular land plants) and have revealed a widespread pattern of conflict with morphology-based classifications. Yet, a comprehensive evaluation of character conflict has not yet been performed in the context of combined matrices. In this study, we evaluate the impact of morphology on bryophyte phylogeny following a total-evidence approach across 10 published matrices. The analysed matrices span a wide range of bryophytes, taxonomic levels, gene sampling and number of morphological characters and taxa. Data conflict was addressed by measuring: (i) the topological congruence between individual partitions, (ii) changes in support values of the combined data relative to the molecular partition and (iii) clade stability. The association between these measures and the number of morphological characters per taxon (Nc/T ratio) and the proportion of non-fixed characters (i.e., inapplicable, polymorphic and missing data) was explored. In the individual partition analyses, the Nc/T ratio correlated positively with the topological congruence in six to seven datasets depending on the weighting scheme. The proportion of non-fixed cells had a minor influence on congruence between data partitions. The number of characters and proportion of non-fixed data varied significantly between morphological datasets that improved congruence between data types. This variation suggests that morphological datasets affect the results of combined analyses in different ways, depending on the taxa studied. Combined analyses revealed that, despite the low congruence values between partitions, integrating data types improves support values and stability. However, while non-fixed data had no negative effect on support values, stability was reduced as the proportion of non-fixed cells increased. Nc/T ratio was negatively associated with support values and it showed ambiguous responses in stability evaluations. Overall, the results indicate that adding morphology may contribute to the inference of phylogenetic relationships of bryophytes despite character conflict. Our findings suggest that merely comparing (a) morphology-based classifications with molecular phylogenies or (b) the outcome from individual data partitions can misestimate data conflict. These findings imply that analyses of combined data may provide conservative assessments of data conflict and, eventually, lead to an improved sampling of morphological characters in large-scale analyses of bryophytes.


Assuntos
Briófitas/anatomia & histologia , Briófitas/classificação , Filogenia , Animais , Briófitas/genética
7.
Cladistics ; 36(6): 569-593, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34618987

RESUMO

The eusporangiate marattialean ferns represent an ancient radiation with a rich fossil record but limited modern diversity in the tropics. The long evolutionary history without close extant relatives has confounded studies of the phylogenetic origin, rooting and timing of marattialean ferns. Here we present new complete plastid genomes of six marattialean species and compiled a plastid genome dataset representing all of the currently accepted marattialean genera. We further supplemented this dataset by compiling a large dataset of mitochondrial genes and a phenotypic data matrix covering both extant and extinct representatives of the lineage. Our phylogenomic and total-evidence analyses corroborated the postulated position of marattialean ferns as the sister to leptosporangiate ferns, and the position of Danaea as the sister to the remaining extant marattialean genera. However, our results provide new evidence that Christensenia is sister to Marattia and that M. cicutifolia actually belongs to Eupodium. The apparently highly reduced rate of molecular evolution in marattialean ferns provides a challenge for dating the key phylogenetic events with molecular clock approaches. We instead applied a parsimony-based total-evidence dating approach, which suggested a Triassic age for the extant crown group. The modern distribution can best be explained as mainly resulting from vicariance following the breakup of Pangaea and Gondwana. We resolved the fossil genera Marattiopsis, Danaeopsis and Qasimia as members of the monophyletic family Marattiaceae, and the Carboniferous genera Sydneia and Radstockia as the monophyletic sister of all other marattialean ferns.

8.
Bioinformatics ; 34(17): 3030-3031, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29659705

RESUMO

Motivation: Genome plotting is performed using a wide range of visualizations tools each with emphasis on a different informative dimension of the genome. These tools can provide a deeper insight into the genomic structure of the organism. Results: Here, we announce a new visualization tool that is specifically designed for chloroplast genomes. It allows the users to depict the genetic architecture of up to ten chloroplast genomes in the vicinity of the sites connecting the inverted repeats to the short and long single copy regions. The software and its dependent libraries are fully coded in R and the reflected plot is scaled up to realistic size of nucleotide base pairs in the vicinity of the junction sites. We introduce a website for easier use of the program and R source code of the software to be used in case of preferences to be changed and integrated into personal pipelines. The input of the program is an annotation GenBank (.gb) file, the accession or GI number of the sequence or a DOGMA output file. The software was tested using over a 100 embryophyte chloroplast genomes and in all cases a reliable output was obtained. Availability and implementation: Source codes and the online suit available at https://irscope.shinyapps.io/irapp/ or https://github.com/Limpfrog/irscope.


Assuntos
Genoma de Cloroplastos , Software , Internet
9.
Cladistics ; 35(4): 351-384, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34633698

RESUMO

Cladoniaceae is a family of lichenized fungi that belongs to the Lecanorales, Ascomycota. The family is distributed widely, although several genera are restricted to the Southern Hemisphere. The circumscriptions of the genera and species in the family have traditionally been based on thallus morphology, the type of vegetative propagules and the secondary metabolites. However, numerous species are highly variable phenotypically, making their delimitation problematic. In the present study a new phylogeny of Cladoniaceae is constructed using five loci (ITS rDNA, IGS rDNA, RPB2, RPB1, EF-1a) from a worldwide sample of 643 specimens representing 304 species. Cladoniaceae was resolved as a monophyletic group. The circumscription of the genera and the relationships among them are discussed. Pycnothelia, Carassea and Metus are closely related, forming a sister clade to the larger genus Cladonia. Cladia in its recent wide sense turned out to be paraphyletic, including species that have been recognized in Thysanothecium and Notocladonia. Cladonia was resolved as monophyletic, with C. wainioi as the earliest diverging lineage. Eleven major clades were resolved in Cladonia. No synapomorphies were found for most of them. We propose the new genera Pulchrocladia and Rexia, as segregates of Cladia, five new combinations, and the resurrection of the genus Heterodea.

10.
PLoS Biol ; 12(1): e1001772, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24465180

RESUMO

Contemporary science thrives on collaborative networks, but these can also be found elsewhere in the history of science in unexpected places. When Mendel turned his attention to inheritance in peas he was not an isolated monk, but rather the latest in a line of Moravian researchers and agriculturalists who had been thinking about inheritance for half a century. Many of the principles of inheritance had already been sketched out by Imre Festetics, a Hungarian sheep breeder active in Brno. Festetics, however, was ultimately hindered by the complex nature of his study traits, aspects of wool quality that we now know to be polygenic. Whether or not Mendel was aware of Festetics's ideas,both men were products of the same vibrant milieu in 19th-century Moravia that combined theory and agricultural practice to eventually uncover the rules of inheritance.


Assuntos
Cruzamento/história , Genética/história , Ovinos/genética , Lã/história , Animais , República Tcheca , Feminino , Hereditariedade , História do Século XVIII , História do Século XIX , Humanos , Hungria , Masculino , Modelos Genéticos , Pisum sativum/genética , Lã/química
11.
BMC Genomics ; 15: 383, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-24884426

RESUMO

BACKGROUND: Mosses are the largest of the three extant clades of gametophyte-dominant land plants and remain poorly studied using comparative genomic methods. Major monophyletic moss lineages are characterised by different types of a spore dehiscence apparatus called the peristome, and the most important unsolved problem in higher-level moss systematics is the branching order of these peristomate clades. Organellar genome sequencing offers the potential to resolve this issue through the provision of both genomic structural characters and a greatly increased quantity of nucleotide substitution characters, as well as to elucidate organellar evolution in mosses. We publish and describe the chloroplast and mitochondrial genomes of Tetraphis pellucida, representative of the most phylogenetically intractable and morphologically isolated peristomate lineage. RESULTS: Assembly of reads from Illumina SBS and Pacific Biosciences RS sequencing reveals that the Tetraphis chloroplast genome comprises 127,489 bp and the mitochondrial genome 107,730 bp. Although genomic structures are similar to those of the small number of other known moss organellar genomes, the chloroplast lacks the petN gene (in common with Tortula ruralis) and the mitochondrion has only a non-functional pseudogenised remnant of nad7 (uniquely amongst known moss chondromes). CONCLUSIONS: Structural genomic features exist with the potential to be informative for phylogenetic relationships amongst the peristomate moss lineages, and thus organellar genome sequences are urgently required for exemplars from other clades. The unique genomic and morphological features of Tetraphis confirm its importance for resolving one of the major questions in land plant phylogeny and for understanding the evolution of the peristome, a likely key innovation underlying the diversity of mosses. The functional loss of nad7 from the chondrome is now shown to have occurred independently in all three bryophyte clades as well as in the early-diverging tracheophyte Huperzia squarrosa.


Assuntos
Briófitas/genética , Genoma de Planta , Sequência de Bases , Briófitas/classificação , Mapeamento Cromossômico , Genoma de Cloroplastos , Genoma Mitocondrial , Dados de Sequência Molecular , Filogenia , Análise de Sequência de RNA
12.
Biotechnol Lett ; 34(6): 1059-65, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22395478

RESUMO

Viscum album (European mistletoe), a perennial, evergreen, hemiparasitic shrub, infects a wide range of woody species. It adversely affects the height and diameter of growth and it is associated with increased mortality of its hosts. There is no effective control methods against it. We have found a specific hyperparasitic fungus, which can completely destroy European mistletoe by infecting its branches, leaves and berries. Both morphological and molecular identification, based on ribosomal internal transcribed spacer sequences (rDNA-ITS), established its identity as Phaeobotryosphaeria visci. Our analysis also revealed unexpected ITS variability, as compared to the previous studies, that needs to be considered in identifying of this pathogen. Because of its efficient pathogenicity this fungus might be a good candidate for biological control of mistletoe.


Assuntos
Ascomicetos/isolamento & purificação , Ascomicetos/patogenicidade , Doenças das Plantas/microbiologia , Viscum album/microbiologia , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Frutas/microbiologia , Filogenia , Folhas de Planta/microbiologia , Análise de Sequência de DNA
13.
Mol Biol Rep ; 38(2): 1171-85, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20574711

RESUMO

Black nightshades are a group of species best known for their 'poisonous' or noxious weedy reputation. It is not so well known that species of this group serve as emerging food source in many countries worldwide especially in the African continent. Despite the fact that the section has recently been studied extensively, taxonomy is still unsettled and debated because of inter- and intraspecific hybridization, phenotypic plasticity and polyploidization. In this study we analyze the genetic relationships among diploid, tetraploid and hexaploid species of sect. Solanum, which have possibly taken part in the formation of Solanum nigrum, utilizing multi-locus (SCoT, ISSR) markers combined with chloroplast trnL-F sequence data and morphological characters. We scored 51 morphological characters united with SCoT (171), ISSR (224) and trnL-F (1042), for simultaneous analysis of 49 terminals and 1488 characters. The topology of the tree is concordant with the results of the network analysis. In the phylogenetic networks, all the accessions of the diploid species shared a split with all of the polyploid species. This reflected a high portion of shared ISSR and SCoT bands between diploids and polyploids. In addition, a strong split divided the diploid species. The history of S. nigrum might be reticulate with hybrid speciation playing an important rule. Genetically differentiated diploids in few combinations have created a series of genetically distinct polyploid populations. The insufficient isolation that permitted further recombination between ancient polyploids and diploids have resulted in high level of genotypic and phenotypic polymorphism. This high level of novel genomic variability obviously enabled species to succeed in their new environment.


Assuntos
Solanum nigrum/metabolismo , Cloroplastos/metabolismo , Códon , Biologia Computacional/métodos , Diploide , Marcadores Genéticos , Genoma de Planta , Genótipo , Modelos Genéticos , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , Folhas de Planta , Polimorfismo Genético , Poliploidia
14.
Mol Biol Rep ; 38(8): 5243-59, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21258867

RESUMO

Kangaroo apples, subgenus Archaesolanum, are a unique and still poorly known group within the genus Solanum. Here we aimed to reveal phylogeny, historical biogeography and age of diversification of Archaesolanum. We sampled all recognized species of the group and sequenced three chloroplast regions, the trnT-trnL spacer, trnL intron and trnL-trnF spacer to calibrate a molecular clock to estimate the age of the group. Distributional data were combined with the results of phylogenetic analysis to track the historical processes responsible for the current range of the group. Our analysis supported the monophyly of the kangaroo apples and the biogeographical disjunction between the two subclades within the group. Based on the divergence time estimates the most recent common ancestor of kangaroo apples is from the late Miocene age (~9 MYA). Based on the age estimate the common ancestors of the kangaroo apples are presumed to have arrived in Australia by long-distance dispersal. The two distinct lineages within the group have separated during the aridification of the continent and further speciated in the brief resurgence of rainforests during the Pliocene.


Assuntos
Malus/genética , Filogenia , Austrália , Teorema de Bayes , Sequência Consenso/genética , Flores/anatomia & histologia , Flores/genética , Geografia , Fatores de Tempo
15.
Biotechnol Lett ; 33(11): 2317-23, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21833547

RESUMO

Non-functional trnF pseudogenes that rarely occur in embryophytes have been found in Solanaceae. We have sequenced the trnL-F intergenic spacer of four species of Solanum, and found duplicated regions of the original trnF gene. These repeats were 94-260 bp long causing large length variation in the trnL-F intergenic spacer resulting from differences in pseudogene copy number (2-4). The duplicated trnF regions are comprised of several highly structured motifs, which were partial residues, or entire parts of the Anticodon, T- and D-domains of the original gene, but all lacked the acceptor stems at the 5'- or 3'-end. Pseudogenes included several transitions and transversions in their sequences compared to the original trnF gene. Among pseudogene copies, T-domains were more frequent and fragmented than D-domain elements. Our results demonstrate that although chloroplast evolution is uniform such structural duplications in the sequences used for phylogenetic reconstructions should be treated with great caution.


Assuntos
Plastídeos/genética , Pseudogenes , Solanum/genética , DNA de Cloroplastos/química , DNA de Cloroplastos/genética , DNA Intergênico , DNA de Plantas/química , DNA de Plantas/genética , Dosagem de Genes , Dados de Sequência Molecular , Mutação , Análise de Sequência de DNA
16.
Mol Phylogenet Evol ; 55(2): 381-98, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20152915

RESUMO

Analysis of an extensive new molecular dataset for the moss class Polytrichopsida provides convincing support for many traditionally recognised genera and identifies higher level phylogenetic structure with a strong geographic component. A large apical clade that is most diverse in the northern hemisphere is subtended by a grade of southern temperate and tropical genera, while the earliest diverging lineages have widely separated relictual distributions. However, there is strongly supported topological incongruence between the nuclear 18S rRNA gene tree and the chloroplast and mitochondrial data for the positions of some taxa and notably for the status of Pogonatum. While Pogonatum is unambiguously paraphyletic in the 18S tree, it is well supported as monophyletic by the combined chloroplast and mitochondrial data, this being corroborated by several distinctive morphological synapomorphies and a 51-53 bp deletion in the rps4-trnS spacer. We explore various reticulate historical processes and methodological issues as possible explanations for incongruence, and suggest that either (1) the 18S topology is an artefact created by convergence of substitutions at specific sites due to functional and/or molecular-structural constraints not accounted for by the model, or (2) the incongruence is a product of ancient hybridization events. Under the latter scenario, incongruent topologies for Pogonatum are parsimoniously explained if Polytrichum (including Polytrichastrum sect. Aporotheca) is ultimately descended from a hybridization event involving an extinct maternal taxon derived from the branch ancestral to the combined Pogonatum/Polytrichum s.l. clade, and a paternal taxon belonging to (or ancestral to) the apical Pogonatum group to which the majority of extant species belong. Numerous novel relationships of taxonomic and evolutionary significance are supported. Notably, both Polytrichastrum and Oligotrichum are polyphyletic. While Polytrichastrum sect. Aporotheca is closely related to Polytrichum, other species, including the type, are not. The large majority of Oligotrichum species sampled occur in one of two distantly related clades with predominantly northern and southern hemisphere distributions, respectively, implying convergent evolution of this morphology in each of the two temperate zones.


Assuntos
Briófitas/genética , Evolução Molecular , Modelos Genéticos , Filogenia , Teorema de Bayes , Briófitas/classificação , Núcleo Celular/genética , DNA Mitocondrial/genética , DNA de Plantas/genética , Geografia , RNA Ribossômico 18S/genética , Alinhamento de Sequência , Análise de Sequência de DNA
17.
Cladistics ; 26(3): 281-300, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34875784

RESUMO

Numerous species of microscopic fungi inhabit mosses and hepatics. They are severely overlooked and their identity and nutritional strategies are mostly unknown. Most of these bryosymbiotic fungi belong to the Ascomycota. Their fruit-bodies are extremely small, often reduced and simply structured, which is why they cannot be reliably identified and classified by their morphological and anatomical characters. A phylogenetic hypothesis of bryosymbiotic ascomycetes is presented. New sequences of 78 samples, including 61 bryosymbionts, were produced, the total amount of terminals being 206. Of these, 202 are Ascomycetes. Sequences from the following five gene loci were used: rDNA SSU, rDNA LSU, RPB2, mitochondrial rDNA SSU, and rDNA 5.8S. The program TNT was used for tree search and support value estimation. We show that bryosymbiotic fungi occur in numerous lineages, one of which represents a newly discovered lineage among the Ascomycota and exhibits a tripartite association with cyanobacteria and sphagna. A new genus Trizodia is proposed for this basal clade. Our results demonstrate that even highly specialized life strategies can be adopted multiple times during evolution, and that in many cases bryosymbionts appear to have evolved from saprobic ancestors. © The Willi Hennig Society 2009.

18.
Mol Biol Rep ; 37(4): 1897-912, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19626457

RESUMO

The nuclear ribosomal locus coding for the large subunit is represented in tandem arrays in the plant genome. These consecutive gene blocks, consisting of several regions, are widely applied in plant phylogenetics. The regions coding for the subunits of the rRNA have the lowest rate of evolution. Also the spacer regions like the internal transcribed spacers (ITS) and external transcribed spacers (ETS) are widely utilized in phylogenetics. The fact, that these regions are present in many copies in the plant genome is an advantage for laboratory practice but might be problem for phylogenetic analysis. Beside routine usage, the rDNA regions provide the great potential to study complex evolutionary mechanisms, such as reticulate events or array duplications. The understanding of these processes is based on the observation that the multiple copies of rDNA regions are homogenized through concerted evolution. This phenomenon results to paralogous copies, which can be misleading when incorporated in phylogenetic analyses. The fact that non-functional copies or pseudogenes can coexist with ortholougues in a single individual certainly makes also the analysis difficult. This article summarizes the information about the structure and utility of the phylogenetically informative spacer regions of the rDNA, namely internal- and external transcribed spacer regions as well as the intergenic spacer (IGS).


Assuntos
Núcleo Celular/genética , DNA Espaçador Ribossômico/genética , Filogenia , Plantas/genética , DNA Espaçador Ribossômico/química , Evolução Molecular , Conformação de Ácido Nucleico , Sequências Repetitivas de Ácido Nucleico/genética , Homologia de Sequência do Ácido Nucleico
19.
Appl Plant Sci ; 8(1): e11313, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31993255

RESUMO

PREMISE: Plant invasions are increasing globally, and extensive study of the genetic background of the source and invading populations is needed to understand such biological processes. For this reason, chloroplast microsatellite markers were identified to explore the genetic diversity of the noxious weed Ambrosia trifida (Asteraceae). METHODS AND RESULTS: The complete chloroplast genome of A. trifida was mined for microsatellite loci, and 15 novel chloroplast primers were identified to assess the genetic diversity of 49 Ambrosia samples. The number of alleles amplified ranged from two to six, with an average of 3.2 alleles per locus. Shannon's information index varied from 0.305 and 1.467, expected heterozygosity ranged from 0.178 to 0.645, and the polymorphism information content value ranged from 0.211 to 0.675 (average 0.428). The cross-species transferability of the 15 microsatellite loci was also evaluated in four related Ambrosia species (A. artemisiifolia, A. maritima, A. psilostachya, and A. tenuifolia). CONCLUSIONS: The novel chloroplast microsatellite markers developed in the current study demonstrate substantial cross-species transferability and will be helpful in future genetic diversity studies of A. trifida and related species.

20.
Front Genet ; 11: 576124, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33101394

RESUMO

Understanding the complexity of genomic structures and their unique architecture is linked with the power of visualization tools used to represent these features. Such tools should be able to provide a realistic and scalable version of genomic content. Here, we present an online organelle plotting tool focused on chloroplasts, which were developed to visualize the exclusive structure of these genomes. The distinguished unique features of this program include its ability to represent the Single Short Copy (SSC) regions in reverse complement, which allows the depiction of the codon usage bias index for each gene, along with the possibility of the minor mismatches between inverted repeat (IR) regions and user-specified plotting layers. The versatile color schemes and diverse functionalities of the program are specifically designed to reflect the accurate scalable representation of the plastid genomes. We introduce a Shiny app website for easy use of the program; a more advanced application of the tool is possible by further development and modification of the downloadable source codes provided online. The software and its libraries are completely coded in R, available at https://irscope.shinyapps.io/chloroplot/.

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