199 resultados para PHYLOGENETIC SYSTEMATICS
Resumo:
The complete SSU rDNA was sequenced for 10 individuals of Cladophora vagabunda collected along the coast of Brazil. For C. rupestris (L.) Kütz. a partial SSU rDNA sequence (1634 bp) was obtained. Phylogenetic trees indicate that Cladophora is paraphyletic, but the section Glomeratae sensu lato including C. vagabunda from Brazil, Japan and France, C. albida (Nees) Kütz., C. sericea (Hudson) Kütz., and C. glomerata (L.) Kütz. is monophyletic. Within this group C. vagabunda is paraphyletic. The sequence identity for the SSU rDNA varied from 98.9% to 100% for the Brazilian C. vagabunda, and from 98.3% to 99.7% comparing the Brazilian individuals to the ones from France and Japan. Sequence identity of the Brazilian C. vagabunda to C. albida and C. sericea vary from 98.0% to 98.6%. The SSU rDNA phylogeny support partially the morphological characteristics presented by Brazilian populations of C. vagabunda. On the other hand, C. rupestris from Brazil does not group with C. rupestris from France, both sequences presenting only 96.9% of identity. The inclusion of sequences of individuals from Brazil reinforces the need of taxonomical revision for the genus Cladophora and for the complex C. vagabunda.
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We present a molecular phylogenetic analysis of caenophidian (advanced) snakes using sequences from two mitochondrial genes (12S and 16S rRNA) and one nuclear (c-mos) gene (1681 total base pairs), and with 131 terminal taxa sampled from throughout all major caenophidian lineages but focussing on Neotropical xenodontines. Direct optimization parsimony analysis resulted in a well-resolved phylogenetic tree, which corroborates some clades identified in previous analyses and suggests new hypotheses for the composition and relationships of others. The major salient points of our analysis are: (1) placement of Acrochordus, Xenodermatids, and Pareatids as successive outgroups to all remaining caenophidians (including viperids, elapids, atractaspidids, and all other "colubrid" groups); (2) within the latter group, viperids and homalopsids are sucessive sister clades to all remaining snakes; (3) the following monophyletic clades within crown group caenophidians: Afro-Asian psammophiids (including Mimophis from Madagascar), Elapidae (including hydrophiines but excluding Homoroselaps), Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae, and Xenodontinae. Homoroselaps is associated with atractaspidids. Our analysis suggests some taxonomic changes within xenodontines, including new taxonomy for Alsophis elegans, Liophis amarali, and further taxonomic changes within Xenodontini and the West Indian radiation of xenodontines. Based on our molecular analysis, we present a revised classification for caenophidians and provide morphological diagnoses for many of the included clades; we also highlight groups where much more work is needed. We name as new two higher taxonomic clades within Caenophidia, one new subfamily within Dipsadidae, and, within Xenodontinae five new tribes, six new genera and two resurrected genera. We synonymize Xenoxybelis and Pseudablabes with Philodryas; Erythrolamprus with Liophis; and Lystrophis and Waglerophis with Xenodon.
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It is presented a cladistic analysis of the Dicrepidiina aiming to test the monophyletism of the subtribe and to establish the relationships among the genera. The subtribe is composed by 36 genera and all of them, except Asebis, Lamononia, Neopsephus, Semiotopsis and Spilomorphus were included in the analysis. Fifty two species, especially the type-species of each genus were studied: Achrestus flavocinctus (Candèze, 1859), A. venustus Champion, 1895, Adiaphorus gracilis Schwarz, 1901, A. ponticerianus Candèze, 1859, Anoplischiopsis bivittatus Champion, 1895, Anoplischius bicarinatus Candèze, 1859, A. conicus Candèze, 1900, A. haematopus Candèze, 1859, A. pyronotus Candèze, 1859, Atractosomus flavescens (Germar, 1839), Blauta cribraria (Germar, 1844), Calopsephus apicalis (Schwarz, 1903), Catalamprus angustus (Fleutiaux, 1902), Crepidius flabellifer (Erichson, 1847), C. resectus Candèze, 1859, Cyathodera auripilosus Costa, 1968, C. lanugicollis (Candèze, 1859), C. longicornis Blanchard, 1843, Dayakus angularis Candèze, 1893, Dicrepidius ramicornis (Palisot de Beauvois, 1805), Dipropus brasilianus (Germar, 1824), D. factuellus Candèze, 1859, D. laticollis (Eschscholtz, 1829), D. pinguis (Candèze, 1859), D. schwarzi (Becker, 1961), Elius birmanicus Candèze, 1893, E. dilatatus Candèze, 1878, Heterocrepidius gilvellus Candèze, 1859, H. ventralis Guérin-Méneville, 1838, Lampropsephus cyaneus (Candèze, 1878), Loboederus appendiculatus (Perty, 1830), Olophoeus gibbus Candèze, 1859, Ovipalpus pubescens Solier, 1851, Pantolamprus ligneus Candèze, 1896, P. mirabilis Candèze, 1896, P. perpulcher Westwood, 1842, Paraloboderus glaber Golbach, 1990, Proloboderus crassipes Fleutiaux, 1912, Propsephus beniensis (Candèze, 1859), P. cavifrons (Erichson, 1843), Pseudolophoeus guineensis (Candèze, 1881), Rhinopsephus apicalis (Schwarz, 1903), Sephilus formosanus Schwarz, 1912, S. frontalis Candèze, 1878, Singhalenus gibbus Candèze, 1892, S. taprobanicus Candèze, 1859, Sphenomerus antennalis Candèze, 1859, S. brunneus Candèze, 1865, Spilus atractomorphus Candèze, 1859, S. nitidus Candèze, 1859, Stenocrepidius simonii Fleutiaux, 1891 and Trielasmus varians Blanchard, 1846. Chalcolepidius zonatus (Hemirhipini, Agrypninae), Ctenicera silvatica (Prosternini, Prosterninae), and species of the other subtribes of Ampedini (Elaterinae): Ampedus sanguineus (Ampedina), Melanotus spernendus (Melanotina) and Anchastus digittatus and Physorhinus xanthocephalus (Physorhinina) were used as outgroups. The results of the phylogenetic analysis demonstrated that Dicrepidiina, as formerly defined, does not form a monophyletic group. One genus, represented by Ovipalpus pubescens, was removed from the subtribe. The subtribe is characterized by presence of lamella under 2nd and 3rd tarsomeres of all legs. Also, it was revealed that the genera Achrestus, Anoplischius, Dipropus and Propsephus are not monophyletic. Due to the scarcity of information, all the studied species are redescribed and illustrated.
Resumo:
Description and phylogenetic analysis of the Calycopidina (Lepidoptera, Lycaenidae, Theclinae, Eumaeini): a subtribe of detritivores. The purpose of this paper is to establish a phylogenetic basis for a new Eumaeini subtribe that includes those lycaenid genera in which detritivory has been recorded. Morphological characters were coded for 82 species of the previously proposed "Lamprospilus Section" of the Eumaeini (19 of these had coding identical to another species), and a phylogenetic analysis was performed using the 63 distinct ingroup terminal taxa and six outgroups belonging to four genera. Taxonomic results include the description in the Eumaeini of Calycopidina Duarte & Robbins new subtribe (type genus Calycopis Scudder, 1876), which contains Lamprospilus Geyer, Badecla Duarte & Robbins new genus (type species Thecla badaca Hewitson), Arzecla Duarte & Robbins new genus (type species Thecla arza Hewitson), Arumecla Robbins & Duarte, Camissecla Robbins & Duarte, Electrostrymon Clench, Rubroserrata K. Johnson & Kroenlein revalidated status, Ziegleria K. Johnson, Kisutam K. Johnson & Kroenlein revalidated status, and Calycopis. Previous "infratribe" names Angulopina K. Johnson & Kroenlein, 1993, and Calycopina K. Johnson & Kroenlein, 1993, are nomenclaturally unavailable and polyphyletic as proposed. New combinations include Badecla badaca (Hewitson), Badecla picentia (Hewitson), Badecla quadramacula (Austin & K. Johnson), Badecla lanckena (Schaus), Badecla argentinensis (K. Johnson & Kroenlein), Badecla clarissa (Draudt), Arzecla arza (Hewitson), Arzecla tarpa (Godman & Salvin), Arzecla canacha (Hewitson), Arzecla calatia (Hewitson), Arzecla tucumanensis (K. Johnson & Kroenlein), Arzecla sethon (Godman & Salvin), Arzecla nubilum (H. H. Druce), Arzecla paralus (Godman & Salvin), Arzecla taminella (Schaus), Arzecla albolineata (Lathy), Electrostrymon denarius (Butler & H.Druce), Electrostrymon guzanta (Schaus), Electrostrymon perisus (H. H. Druce), Rubroserrata mathewi (Hewitson), Rubroserrata ecbatana (Hewitson), Kisutam micandriana (K. Johnson), and Kisutam syllis (Godman & Salvin). The structure of the male genitalia lateral window, labides, and brush organs are described and discussed, as are the female genitalia signa of the corpus bursae and 8th abdominal tergum. Widespread wing pattern sexual dimorphism in the Calycopidina is noted and illustrated, and the presence of alternating dark and light bands on the ventral wings of both sexes is discussed. The evidence for detritivory in Lamprospilus, Badecla, Arzecla, Arumecla, Camissecla, Electrostrymon, Ziegleria, Kisutam, and Calycopis is summarized using the new classification.
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Background: Polypodium hydriforme is a parasite with an unusual life cycle and peculiar morphology, both of which have made its systematic position uncertain. Polypodium has traditionally been considered a cnidarian because it possesses nematocysts, the stinging structures characteristic of this phylum. However, recent molecular phylogenetic studies using 18S rDNA sequence data have challenged this interpretation, and have shown that Polypodium is a close relative to myxozoans and together they share a closer affinity to bilaterians than cnidarians. Due to the variable rates of 18S rDNA sequences, these results have been suggested to be an artifact of long-branch attraction ( LBA). A recent study, using multiple protein coding markers, shows that the myxozoan Buddenbrockia, is nested within cnidarians. Polypodium was not included in this study. To further investigate the phylogenetic placement of Polypodium, we have performed phylogenetic analyses of metazoans with 18S and partial 28S rDNA sequences in a large dataset that includes Polypodium and a comprehensive sampling of cnidarian taxa. Results: Analyses of a combined dataset of 18S and partial 28S sequences, and partial 28S alone, support the placement of Polypodium within Cnidaria. Removal of the long-branched myxozoans from the 18S dataset also results in Polypodium being nested within Cnidaria. These results suggest that previous reports showing that Polypodium and Myxozoa form a sister group to Bilateria were an artifact of long-branch attraction. Conclusion: By including 28S rDNA sequences and a comprehensive sampling of cnidarian taxa, we demonstrate that previously conflicting hypotheses concerning the phylogenetic placement of Polypodium can be reconciled. Specifically, the data presented provide evidence that Polypodium is indeed a cnidarian and is either the sister taxon to Hydrozoa, or part of the hydrozoan clade, Leptothecata. The former hypothesis is consistent with the traditional view that Polypodium should be placed in its own cnidarian class, Polypodiozoa.
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The availaibilty of chloroplast genome (cpDNA) sequences of Atropa belladonna, Nicotiana sylvestris, N tabacum, N tomentosiformis, Solanum bulbocastanum, S lycopersicum and S tuberosum, which are Solanaceae species, allowed us to analyze the organization of cpSSRs in their genic and intergenic regions In general, the number of cpSSRs in cpDNA ranged from 161 in S tuberosum to 226 in N tabacum, and the number of intergenic cpSSRs was higher than genic cpSSRs The mononucleotide repeats were the most frequent in studied species, but we also identified di-, tri-, tetra-, penta- and hexanucleotide repeats Multiple alignments of all cpSSRs sequence from Solanaceae species made the identification of nucleotide variability possible and the phylogeny was estimated by maximum parsimony Our study showed that the plastome database can be exploited for phylogenetic analyses and biotechnological approaches
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Background: Polymorphisms of the mannose-binding lectin gene (MBL2) affect the concentration and functional efficiency of the protein. We recently used haplotype-specific sequencing to identify 23 MBL2 haplotypes, associated with enhanced susceptibility to several diseases. Results: In this work, we applied the same method in 288 and 470 chromosomes from Gabonese and European adults, respectively, and found three new haplotypes in the last group. We propose a phylogenetic nomenclature to standardize MBL2 studies and found two major phylogenetic branches due to six strongly linked polymorphisms associated with high MBL production. They presented high Fst values and were imbedded in regions with high nucleotide diversity and significant Tajima's D values. Compared to others using small sample sizes and unphased genotypic data, we found differences in haplotyping, frequency estimation, Fu and Li's D* and Fst results. Conclusion: Using extensive testing for selective neutrality, we confirmed that stochastic evolutionary factors have had a major role in shaping this polymorphic gene worldwide.
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Background: The thin-spined porcupine, also known as the bristle-spined rat, Chaetomys subspinosus (Olfers, 1818), the only member of its genus, figures among Brazilian endangered species. In addition to being threatened, it is poorly known, and even its taxonomic status at the family level has long been controversial. The genus Chaetomys was originally regarded as a porcupine in the family Erethizontidae, but some authors classified it as a spiny-rat in the family Echimyidae. Although the dispute seems to be settled in favor of the erethizontid advocates, further discussion of its affinities should be based on a phylogenetic framework. In the present study, we used nucleotide-sequence data from the complete mitochondrial cytochrome b gene and karyotypic information to address this issue. Our molecular analyses included one individual of Chaetomys subspinosus from the state of Bahia in northeastern Brazil, and other hystricognaths. Results: All topologies recovered in our molecular phylogenetic analyses strongly supported Chaetomys subspinosus as a sister clade of the erethizontids. Cytogenetically, Chaetomys subspinosus showed 2n = 52 and FN = 76. Although the sexual pair could not be identified, we assumed that the X chromosome is biarmed. The karyotype included 13 large to medium metacentric and submetacentric chromosome pairs, one small subtelocentric pair, and 12 small acrocentric pairs. The subtelocentric pair 14 had a terminal secondary constriction in the short arm, corresponding to the nucleolar organizer region (Ag-NOR), similar to the erethizontid Sphiggurus villosus, 2n = 42 and FN = 76, and different from the echimyids, in which the secondary constriction is interstitial. Conclusion: Both molecular phylogenies and karyotypical evidence indicated that Chaetomys is closely related to the Erethizontidae rather than to the Echimyidae, although in a basal position relative to the rest of the Erethizontidae. The high levels of molecular and morphological divergence suggest that Chaetomys belongs to an early radiation of the Erethizontidae that may have occurred in the Early Miocene, and should be assigned to its own subfamily, the Chaetomyinae.
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Marinussaurus curupira, a new genus and species of Gymnophthalmidae lizard is described from Iranduba, state of Amazonas, Brazil. The genus is characterized by an elongate body; short and stout pentadactyl limbs; all digits clawed; single frontonasal; two prefrontals; absence of frontoparietals; interparietal and parietals forming a straight posterior margin, with interparietal shorter than parietals; distinctive ear opening and eyelid; few temporals; three pairs of chin shields; nasal divided; a distinct collar; smooth, mainly hexagonal, dorsal scales; smooth quadrangular ventral scales; two precloacal and three femoral pores on each side in males; pores between three or four scales. Parsimony (PAR) and partitioned Bayesian (BA) phylogenetic analyses with morphological and molecular data recovered the new genus as a member of the Ecpleopodini radiation of the Cercosaurinae. A close relationship of the new genus with Arthrosaura is postulated.
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Background: Mites (Acari) have traditionally been treated as monophyletic, albeit composed of two major lineages: Acariformes and Parasitiformes. Yet recent studies based on morphology, molecular data, or combinations thereof, have increasingly drawn their monophyly into question. Furthermore, the usually basal (molecular) position of one or both mite lineages among the chelicerates is in conflict to their morphology, and to the widely accepted view that mites are close relatives of Ricinulei. Results: The phylogenetic position of the acariform mites is examined through employing SSU, partial LSU sequences, and morphology from 91 chelicerate extant terminals (forty Acariformes). In a static homology framework, molecular sequences were aligned using their secondary structure as guide, whereby regions of ambiguous alignment were discarded, and pre-aligned sequences analyzed under parsimony and different mixed models in a Bayesian inference. Parsimony and Bayesian analyses led to trees largely congruent concerning infraordinal, well-supported branches, but with low support for inter-ordinal relationships. An exception is Solifugae + Acariformes (P. P = 100%, J. = 0.91). In a dynamic homology framework, two analyses were run: a standard POY analysis and an analysis constrained by secondary structure. Both analyses led to largely congruent trees; supporting a (Palpigradi (Solifugae Acariformes)) clade and Ricinulei as sister group of Tetrapulmonata with the topology (Ricinulei (Amblypygi (Uropygi Araneae))). Combined analysis with two different morphological data matrices were run in order to evaluate the impact of constraining the analysis on the recovered topology when employing secondary structure as a guide for homology establishment. The constrained combined analysis yielded two topologies similar to the exclusively molecular analysis for both morphological matrices, except for the recovery of Pedipalpi instead of the (Uropygi Araneae) clade. The standard (direct optimization) POY analysis, however, led to the recovery of trees differing in the absence of the otherwise well-supported group Solifugae + Acariformes. Conclusions: Previous studies combining ribosomal sequences and morphology often recovered topologies similar to purely morphological analyses of Chelicerata. The apparent stability of certain clades not recovered here, like Haplocnemata and Acari, is regarded as a byproduct of the way the molecular homology was previously established using the instrumentalist approach implemented in POY. Constraining the analysis by a priori homology assessment is defended here as a way of maintaining the severity of the test when adding new data to the analysis. Although the strength of the method advocated here is keeping phylogenetic information from regions usually discarded in an exclusively static homology framework; it still has the inconvenience of being uninformative on the effect of alignment ambiguity on resampling methods of clade support estimation. Finally, putative morphological apomorphies of Solifugae + Acariformes are the reduction of the proximal cheliceral podomere, medial abutting of the leg coxae, loss of sperm nuclear membrane, and presence of differentiated germinative and secretory regions in the testis delivering their products into a common lumen.
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It has been known for decades that some insect-infecting trypanosomatids can survive in culture without heme supplementation while others cannot, and that this capability is associated with the presence of a betaproteobacterial endosymbiont in the flagellate's cytoplasm. However, the specific mechanisms involved in this process remained obscure. In this work, we sequence and phylogenetically analyze the heme pathway genes from the symbionts and from their hosts, as well as from a number of heme synthesis-deficient Kinetoplastida. Our results show that the enzymes responsible for synthesis of heme are encoded on the symbiont genomes and produced in close cooperation with the flagellate host. Our evidence suggests that this synergistic relationship is the end result of a history of extensive gene loss and multiple lateral gene transfer events in different branches of the phylogeny of the Trypanosomatidae.
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The paired fronto-lateral gland pores and lattice organs (LO1, 2, 3, 4, and 5) of seven species of pedunculate barnacles belonging to two thoracican suborders, Heteralepadomorpha (family Heteralepadidae: Heteralepas sp. 1 and 2) and Lepadomorpha (families Poecilasmatidae: Poecilasma inaequilaterale and Octolasmis aymonini geryonophila and Lepadidae: Lepas pacifica, Dosima fascicularis, and Conchoderma virgatum), were investigated by scanning electron microscopy (SEM). While the fronto-lateral gland pores exhibit slight variation among species, with only L. pacifica showing a different morphology, the variations in the arrangement of LOs are phylogenetically instructive. The lattice organs in the foregoing species correspond in general to the inferred advanced type (Type C), but the distinct keel in the pore field in P. inaequilaterale and L. pacifica is reminiscent of, but not necessarily identical with the less advanced Type B. The arrangement of the anterior LOs (1-2) is rhomboidal in the two heteralepadomorph species, the two poecilasmatid species, and two of the three lepadid species, as it is in all previously and presently known lepadomorph cyprids except D. fascicularis. In this last species, they are deployed linearly along the hinge line. A linear arrangement of all the lattice organs is presumably the plesiomorphic condition for the Thoracica; an obvious exception being the pattern seen in Ibla cumingi. The arrangement of the first two pairs of posterior LOs (3-4) in O. a. geryonophila and C. virgatum differs from that of all previously described Lepadomorpha in being rhomboidal rather than aligned linearly along the hinge line. This same arrangement of LOs 3 and 4 in the two heteralepadomorph species is notable since it is not known in other thoracicans. Our results concerning variation in lattice organs of the lower Pedunculata are more or less consistent with current phylogenetic speculations and genetic information that ally Heteralepadomorpha with Lepadomorpha. Significance of this variation at lower taxonomic levels is also evident in the two similar forms of Heteralepas.
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The Neotropical lycaenid hairstreak genus Thepytus Robbins and its eight species are revised. Species treatments summarize nomenclature, distribution, habitat, behavior, and diagnostic traits, as well as noting why each species is considered distinct under a biological species concept. An identification key for males and a checklist are included. Beatheclus Balint & Dahners new synonym is synonymized with Thepytus, and Theppus beatrizae (Balint & Dahners) is a new combination. Other nomenclatural actions include the description of Thepytus jennifer Busby & Robbins new species. Thepytus nancyana Busby & Robbins new species, and Thepytus carmen Robbins & Duarte new species. A lectotype is designated or Thecla thyrea Hewitson, 1867, to ensure stability of this name. A phylogenetic analysis based on 22 coded morphological characters yields one equal weight most parsimonious 39-step tree. Implied weighting does not change the tree topology. Unambiguous changes in elevation optimized on the cladogram show that a montane lineage of Thepytus colonized the lowlands in at least one instance. The use of T. echelta (Hewitson) as a biological control agent for Psittacanthus (Loranthaceae) is discussed.
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Medusae and polyps of Clytia are abundantly found in coastal marine environments and one species in the genus-Clytia hemisphaerica (Linnaeus, 1767)-has become an important experimental model. Yet, only 10 species in the genus have had their life cycle investigated. Most species of Clytia are also poorly described, and detailed life cycle and morphological studies are needed for accurate species-level identifications. Here, we investigated the life cycle of Clytia elsaeoswaldae Stechow, 1914, a species described for the tropical western Atlantic and subsequently considered conspecific to the nearly-cosmopolitan species Clytia gracilis (Sars, 1850) and Clytia hemisphaerica, originally described for the temperate North Atlantic. Based on observations of mature medusae and multiple colonies from southeastern Brazil and the U. S. Virgin Islands (type locality), our results show that C. elsaeoswaldae is morphologically distinct from C. gracilis and C. hemisphaerica. The morphological results are corroborated by a multigene phylogenetic analysis of the genus Clytia, which shows that C. gracilis-like species form a polyphyletic group of several species. These results suggest that the nearly-cosmopolitan distribution attributed to some species of Clytia may be due to the non-recognition of morphologically similar species with more restricted ranges.
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The cuticular surfaces of Cyphophthalmi (Opiliones) were studied in detail, covering a wide range of their taxonomic diversity. Previously unknown structures are described, including a sexually dimorphic row of spines and glandular openings on leg I of Fangensis cavernarum. Scanning electron micrographs of the prosomal paired hairs and the subapical process are provided for the first time. Evidence for the multi-pored nature of the shaft of solenidia as well as the hollowed nature and absence of wall pores of sensilla chaetica are also shown for the first time using scanning electron microscopy. The prosomal paired hairs may constitute a novel autapomorphy for Cyphophthalmi, as they are absent in all studied members of the other species of Opiliones. Finally, the variation in shape of some of the structures examined may be of great taxonomic value.