Displaying publications 241 - 260 of 1820 in total

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  1. Phylogenetic relationships, morphological variation, and toxin patterns in the Alexandrium ostenfeldii (Dinophyceae) complex: implications for species boundaries and identities
    Kremp A, Tahvanainen P, Litaker W, Krock B, Suikkanen S, Leaw CP, et al.
    J Phycol, 2014 Feb;50(1):81-100.
    PMID: 26988010 DOI: 10.1111/jpy.12134
    Alexandrium ostenfeldii (Paulsen) Balech and Tangen and A. peruvianum (Balech and B.R. Mendiola) Balech and Tangen are morphologically closely related dinoflagellates known to produce potent neurotoxins. Together with Gonyaulax dimorpha Biecheler, they constitute the A. ostenfeldii species complex. Due to the subtle differences in the morphological characters used to differentiate these species, unambiguous species identification has proven problematic. To better understand the species boundaries within the A. ostenfeldii complex we compared rDNA data, morphometric characters and toxin profiles of multiple cultured isolates from different geographic regions. Phylogenetic analysis of rDNA sequences from cultures characterized as A. ostenfeldii or A. peruvianum formed a monophyletic clade consisting of six distinct groups. Each group examined contained strains morphologically identified as either A. ostenfeldii or A. peruvianum. Though key morphological characters were generally found to be highly variable and not consistently distributed, selected plate features and toxin profiles differed significantly among phylogenetic clusters. Additional sequence analyses revealed a lack of compensatory base changes in ITS2 rRNA structure, low to intermediate ITS/5.8S uncorrected genetic distances, and evidence of reticulation. Together these data (criteria currently used for species delineation in dinoflagellates) imply that the A. ostenfeldii complex should be regarded a single genetically structured species until more material and alternative criteria for species delimitation are available. Consequently, we propose that A. peruvianum is a heterotypic synonym of A. ostenfeldii and this taxon name should be discontinued.
    Matched MeSH terms: Phylogeny
  2. Resolving phenotypic plasticity and species designation in the morphologically challenging Caulerpa racemosa-peltata complex (Chlorophyta, Caulerpaceae)
    Belton GS, van Reine WF, Huisman JM, Draisma SG, D Gurgel CF
    J Phycol, 2014 Feb;50(1):32-54.
    PMID: 26988007 DOI: 10.1111/jpy.12132
    Although recent molecular studies have indicated the presence of a number of distinct species within the Caulerpa racemosa-peltata complex, due to the difficulties presented by high levels of phenotypic plasticity and the large number of synonyms, infra-specific taxa, and names of uncertain affinity, taxonomic proposals are yet to be made. In this study, we aimed to resolve the taxonomy of the complex and provide an example of how historical nomenclature can best be integrated into molecular based taxonomies. We accomplished this by first determining the number of genetic species within our globally sampled data set through a combination of phylogenetic and species-delimitation approaches of partial elongation factor TU and RUBISCO large subunit gene sequences. Guided by these results, comparative morphological examinations were then undertaken to gauge the extent of phenotypic plasticity within each species, as well as any morphological overlap between them. Our results revealed the presence of 11 distinct species within the complex, five of which showed high levels of phenotypic plasticity and partial overlap with other species. On the basis of observations of a large number of specimens, including type specimens/descriptions, and geographic inferences, we were able to confidently designate names for the lineages. Caulerpa peltata, C. imbricata and C. racemosa vars. laetevirens, occidentalis and turbinata were found to represent environmentally induced forms of a single species, for which the earlier-described C. chemnitzia, previously regarded as a synonym of C. racemosa var. turbinata, is reinstated. C. cylindracea, C. lamourouxii, C. macrodisca, C. nummularia and C. oligophylla are also reinstated and two new species, C. macra stat. nov. and C. megadisca sp. nov., are proposed.
    Matched MeSH terms: Phylogeny
  3. First record of the tree-frog genus Chiromantis from Borneo with the description of a new species (Amphibia: Rhacophoridae)
    Matsui M, Shimada T, Sudin A
    Zoolog Sci, 2014 Jan;31(1):45-51.
    PMID: 24410495 DOI: 10.2108/zsj.31.45
    We record a tree frog of the genus Chiromantis for the first time from outside the Southeast Asian continent and describe it as a new species, Chiromantis inexpectatus. The new species from the Malaysian state of Sabah, Borneo, is a small-sized Chiromantis (male snout-vent length ca. 22 mm), and is distinguished from all other members of the genus by the combination of the following morphological characteristics: dark stripes absent, but dark spots present on dorsum; a dark-brown lateral band present from snout tip to half of body, bordered ventrally by white stripe; third and fourth fingers less than half webbed; third finger disk wider than tympanum diameter; and inner metatarsal tubercle present. Significance of findings of this species from Borneo Island, as well as phylogeny and breeding habit of the genus Chiromantis, are briefly discussed.
    Matched MeSH terms: Phylogeny
  4. Autecology and phylogeny of Coolia tropicalis and Coolia malayensis (Dinophyceae), with emphasis on taxonomy of C. tropicalis based on light microscopy, scanning electron microscopy and LSU rDNA(1)
    Mohammad-Noor N, Moestrup Ø, Lundholm N, Fraga S, Adam A, Holmes MJ, et al.
    J Phycol, 2013 Jun;49(3):536-45.
    PMID: 27007042 DOI: 10.1111/jpy.12062
    Coolia is a widespread and ecologically important genus of benthic marine dinoflagellates found in tropical regions. Historically, there has been taxonomic confusion about the taxonomy and toxicity of this group. The goal of this study was to resolve morphological questions concerning Coolia tropicalis and determine the taxonomic identity of the Australian Coolia isolate which has been reported to produce cooliatoxins. To accomplish this, the morphology of tropical strains from Belize (the type locality of C. tropicalis), Malaysia, Indonesia, and Australia were examined and compared to published reports. The morphological analysis showed that C. tropicalis differs from the original description in that it has a slightly larger size (35-47 μm long by 30-45 μm wide versus 23-40 μm long by 25-39 μm wide), and the shape of fourth apical plate, and the length of Po plate (7.4-12 μm versus 7 μm). Based on both morphology and phylogenetic analysis using LSU D1- D3 rDNA sequences, the clones of C. tropicalis from Malaysia, Indonesia, and Belize were found to form a monophyletic clade within the genus. The strain producing cooliatoxin was found to be C. tropicalis, not Coolia monotis as originally assumed. To explore the factors influencing the growth of Coolia species, the growth rates of C. tropicalis and Coolia malayensis were determined at different temperatures and salinities. Both species tolerated a wide range of temperatures, but cannot survive at temperatures <20°C or >35°C. C. monotis, the dominant species reported in the literature, probably does not produce toxins.
    Matched MeSH terms: Phylogeny
  5. Fulltext Genetic diversity of upland rice germplasm in Malaysia based on quantitative traits
    Sohrabi M, Rafii MY, Hanafi MM, Siti Nor Akmar A, Latif MA
    ScientificWorldJournal, 2012;2012:416291.
    PMID: 22654604 DOI: 10.1100/2012/416291
    Genetic diversity is prerequisite for any crop improvement program as it helps in the development of superior recombinants. Fifty Malaysian upland rice accessions were evaluated for 12 growth traits, yield and yield components. All of the traits were significant and highly significant among the accessions. The higher magnitudes of genotypic and phenotypic coefficients of variation were recorded for flag leaf length-to-width ratio, spikelet fertility, and days to flowering. High heritability along with high genetic advance was registered for yield of plant, days to flowering, and flag leaf length-to-width ratio suggesting preponderance of additive gene action in the gene expression of these characters. Plant height showed highly significant positive correlation with most of the traits. According to UPGMA cluster analysis all accessions were clustered into six groups. Twelve morphological traits provided around 77% of total variation among the accessions.
    Matched MeSH terms: Phylogeny
  6. A TAXONOMIC STUDY OF THE GENUS PADINA (DICTYOTALES, PHAEOPHYCEAE) INCLUDING THE DESCRIPTIONS OF FOUR NEW SPECIES FROM JAPAN, HAWAII, AND THE ANDAMAN SEA(1)
    Win NN, Hanyuda T, Arai S, Uchimura M, Prathep A, Draisma SG, et al.
    J Phycol, 2011 Oct;47(5):1193-209.
    PMID: 27028247 DOI: 10.1111/j.1529-8817.2011.01054.x
    A taxonomic study of the genus Padina from Japan, Southeast Asia, and Hawaii based on morphology and gene sequence data (rbcL and cox3) resulted in the recognition of four new species, that is, Padina macrophylla and Padina ishigakiensis from Ryukyu Islands, Japan; Padina maroensis from Hawaii; and Padina usoehtunii from Myanmar and Thailand. All species are bistratose and morphologically different from one another as well as from any known taxa by a combination of characters relating to degree of calcification; the structure, position, and arrangement of hairlines (HLs) and reproductive sori; and the presence or absence of rhizoid-like groups of hairs and an indusium. Molecular phylogenetic analyses demonstrated a close relationship between P. ishigakiensis, P. macrophylla, P. maroensis, and Padina australis Hauck. The position of P. usoehtunii, however, was not fully resolved, being either sister to a clade comprising the other three new species and P. australis in the rbcL tree or more closely related to a clade comprising several other recently described species in the cox3 tree. The finding of the four new species demonstrates high species diversity particularly in southern Japan. The following characters were first recognized here to be useful for species delimitation: the presence or absence of small rhizoid-like groups of hairs on the thallus surface, structure and arrangement of HLs on both surfaces either alternate or irregular, and arrangement of the alternating HLs between both surfaces in equal or unequal distance. The evolutionary trajectory of these and six other morphological characters used in species delineation was traced on the phylogenetic tree.
    Matched MeSH terms: Phylogeny
  7. [A redescription of Macrostylophora borneensis (Jordan, 1926) (Siphonaptera-Ceratophyllidae-Ceratophyllinae), a flea of the Malaysian sub-region and description of an allied species]
    Beaucournu JC, Wells K
    Parasite, 2005 Dec;12(4):293-8.
    PMID: 16402560
    This note redescribes M. borneensis and describes M. traubi n. sp. based on the known specimens from the two sampling localities (holotype from Mount Murud and further recorded from Mount Kinabalu by Traub). The clearly allied, but clearly distinct species for the two localities, were recorded.
    Matched MeSH terms: Phylogeny
  8. Ciimaerocyon gen. nov., a morphologically aberrant myrmecophilous genus of water scavenger beetle (Coleoptera: Hydrophilidae: Sphaeridiinae)
    Fikáček M, Maruyama M, Vondráček D, Short AE
    Zootaxa, 2013;3716:277-88.
    PMID: 26106776
    Anew hydrophilid genus Chimaerocyon gen. nov. containing two species, C. shimadai sp. nov. (Malaysia: Pahang) and C. sumatranus sp. nov. (Indonesia: Sumatra), is described. Specimens of C. shimadai were collected from brood cells in anest of Pheidole singaporensis Özdikmen, 2010. The biology of C. sumatranus remains unknown. A molecular phylogeny based on four genes (cox1, cox2, 18S and 28S) supports the placement of the genus as deeply nested within the Cercyon-group of the tribe Megasternini. This position is supported by the subdistal position of the median spur in the hind wing (unique to Megasternini) and the presence of sucking disc on male maxilla (unique for Megastemini+Sphaeridiini). The remaining external morphology differs substantially from other representatives of Megasternini. The hypothesis that the aberrant morphology of Chimaerocyon gen. nov. is a consequence of myrmecophily is discussed.
    Matched MeSH terms: Phylogeny
  9. Discovery of a new polyhydroxyalkanoate synthase from limestone soil through metagenomic approach
    Tai YT, Foong CP, Najimudin N, Sudesh K
    J Biosci Bioeng, 2016 Apr;121(4):355-64.
    PMID: 26467694 DOI: 10.1016/j.jbiosc.2015.08.008
    PHA synthase (PhaC) is the key enzyme in the production of biodegradable plastics known as polyhydroxyalkanoate (PHA). Nevertheless, most of these enzymes are isolated from cultivable bacteria using traditional isolation method. Most of the microorganisms found in nature could not be successfully cultivated due to the lack of knowledge on their growth conditions. In this study, a culture-independent approach was applied. The presence of phaC genes in limestone soil was screened using primers targeting the class I and II PHA synthases. Based on the partial gene sequences, a total of 19 gene clusters have been identified and 7 clones were selected for full length amplification through genome walking. The complete phaC gene sequence of one of the clones (SC8) was obtained and it revealed 81% nucleotide identity to the PHA synthase gene of Chromobacterium violaceum ATCC 12472. This gene obtained from uncultured bacterium was successfully cloned and expressed in a Cupriavidus necator PHB(-)4 PHA-negative mutant resulting in the accumulation of significant amount of PHA. The PHA synthase activity of this transformant was 64 ± 12 U/g proteins. This paper presents a pioneering study on the discovery of phaC in a limestone area using metagenomic approach. Through this study, a new functional phaC was discovered from uncultured bacterium. Phylogenetic classification for all the phaCs isolated from this study has revealed that limestone hill harbors a great diversity of PhaCs with activities that have not yet been investigated.
    Matched MeSH terms: Phylogeny
  10. Fulltext Dormant phages of Helicobacter pylori reveal distinct populations in Europe
    Vale FF, Vadivelu J, Oleastro M, Breurec S, Engstrand L, Perets TT, et al.
    Sci Rep, 2015;5:14333.
    PMID: 26387443 DOI: 10.1038/srep14333
    Prophages of Helicobacter pylori, a bacterium known to co-evolve in the stomach of its human host, were recently identified. However, their role in the diversity of H. pylori strains is unknown. We demonstrate here and for the first time that the diversity of the prophage genes offers the ability to distinguish between European populations, and that H. pylori prophages and their host bacteria share a complex evolutionary history. By comparing the phylogenetic trees of two prophage genes (integrase and holin) and the multilocus sequence typing (MLST)-based data obtained for seven housekeeping genes, we observed that the majority of the strains belong to the same phylogeographic group in both trees. Furthermore, we found that the Bayesian analysis of the population structure of the prophage genes identified two H. pylori European populations, hpNEurope and hpSWEurope, while the MLST sequences identified one European population, hpEurope. The population structure analysis of H. pylori prophages was even more discriminative than the traditional MLST-based method for the European population. Prophages are new players to be considered not only to show the diversity of H. pylori strains but also to more sharply define human populations.
    Matched MeSH terms: Phylogeny
  11. Fulltext Complete genome sequencing of Pandoraea pnomenusa RB38 and Molecular Characterization of Its N-acyl homoserine lactone synthase gene ppnI
    Lim YL, Ee R, How KY, Lee SK, Yong D, Tee KK, et al.
    PeerJ, 2015;3:e1225.
    PMID: 26336650 DOI: 10.7717/peerj.1225
    In this study, we sequenced the genome of Pandoraea pnomenusa RB38 using Pacific Biosciences RSII (PacBio) Single Molecule Real Time (SMRT) sequencing technology. A pair of cognate luxI/R homologs was identified where the luxI homolog, ppnI, was found adjacent to a luxR homolog, ppnR1. An additional orphan luxR homolog, ppnR2, was also discovered. Multiple sequence alignment and phylogenetic analysis revealed that ppnI is an N-acyl homoserine lactone (AHL) synthase gene that is distinct from those of the nearest phylogenetic neighbor viz. Burkholderia spp. High resolution tandem mass spectrometry (LC-MS/MS) analysis showed that Escherichia coli BL21 harboring ppnI produced a similar AHL profile (N-octanoylhomoserine lactone, C8-HSL) as P. pnomenusa RB38, the wild-type donor strain, confirming that PpnI directed the synthesis of AHL in P. pnomenusa RB38. To our knowledge, this is the first documentation of the luxI/R homologs of the genus Pandoraea.
    Matched MeSH terms: Phylogeny
  12. Fulltext Breakdown of coevolution between symbiotic bacteria Wolbachia and their filarial hosts
    Lefoulon E, Bain O, Makepeace BL, d'Haese C, Uni S, Martin C, et al.
    PeerJ, 2016;4:e1840.
    PMID: 27069790 DOI: 10.7717/peerj.1840
    Wolbachia is an alpha-proteobacterial symbiont widely distributed in arthropods. Since the identification of Wolbachia in certain animal-parasitic nematodes (the Onchocercidae or filariae), the relationship between arthropod and nematode Wolbachia has attracted great interest. The obligate symbiosis in filariae, which renders infected species susceptible to antibiotic chemotherapy, was held to be distinct from the Wolbachia-arthropod relationship, typified by reproductive parasitism. While co-evolutionary signatures in Wolbachia-arthropod symbioses are generally weak, reflecting horizontal transmission events, strict co-evolution between filariae and Wolbachia has been reported previously. However, the absence of close outgroups for phylogenetic studies prevented the determination of which host group originally acquired Wolbachia. Here, we present the largest co-phylogenetic analysis of Wolbachia in filariae performed to date including: (i) a screening and an updated phylogeny of Wolbachia; (ii) a co-phylogenetic analysis; and (iii) a hypothesis on the acquisition of Wolbachia infection. First, our results show a general overestimation of Wolbachia occurrence and support the hypothesis of an ancestral absence of infection in the nematode phylum. The accuracy of supergroup J is also underlined. Second, although a global pattern of coevolution remains, the signal is derived predominantly from filarial clades associated with Wolbachia in supergroups C and J. In other filarial clades, harbouring Wolbachia supergroups D and F, horizontal acquisitions and secondary losses are common. Finally, our results suggest that supergroup C is the basal Wolbachia clade within the Ecdysozoa. This hypothesis on the origin of Wolbachia would change drastically our understanding of Wolbachia evolution.
    Matched MeSH terms: Phylogeny
  13. Preface and Constitution of the Asian Society of Ichthyologists
    Page LM, Nor SA
    Zootaxa, 2015;3962(1):5-9.
    PMID: 26249377 DOI: 10.11646/zootaxa.3962.1.3
    The U.S. National Science Foundation-funded (DEB 1022720) 'All Cypriniformes Species Inventory' was initiated in 2010 and will be completed in 2015.  It has accelerated the rate of discovery and description of cypriniform fishes, expanded our knowledge of the phylogenetic relationships of cypriniforms, increased the capacity for systematic research in other countries through student training and establishing long-term collaborations, including conferences in Thailand in 2012, Brunei in 2013, Burundi in 2013, and Malaysia in 2014, led to the formation of the Asian Society of Ichthyologists, and made available large numbers of specimens and tissues of freshwater fishes, including many species never before collected, in permanent collections in foreign and U.S. institutions.
    Matched MeSH terms: Phylogeny
  14. Fulltext Mitochondrial Genome Supports Sibling Species of Angiostrongylus costaricensis (Nematoda: Angiostrongylidae)
    Yong HS, Song SL, Eamsobhana P, Goh SY, Lim PE, Chow WL, et al.
    PLoS One, 2015;10(7):e0134581.
    PMID: 26230642 DOI: 10.1371/journal.pone.0134581
    Angiostrongylus costaricensis is a zoonotic parasitic nematode that causes abdominal or intestinal angiostrongyliasis in humans. It is endemic to the Americas. Although the mitochondrial genome of the Brazil taxon has been published, there is no available mitochondrial genome data on the Costa Rica taxon. We report here the complete mitochondrial genome of the Costa Rica taxon and its genetic differentiation from the Brazil taxon. The whole mitochondrial genome was obtained from next-generation sequencing of genomic DNA. It had a total length of 13,652 bp, comprising 36 genes (12 protein-coding genes-PCGs, 2 rRNA and 22 tRNA genes) and a control region (A + T rich non-coding region). It is longer than that of the Brazil taxon (13,585 bp). The larger mitogenome size of the Costa Rica taxon is due to the size of the control region as the Brazil taxon has a shorter length (265 bp) than the Costa Rica taxon (318 bp). The size of 6 PCGs and the start codon for ATP6, CYTB and NAD5 genes are different between the Costa Rica and Brazil taxa. Additionally, the two taxa differ in the stop codon of 6 PCGs. Molecular phylogeny based on 12 PCGs was concordant with two rRNA, 22 tRNA and 36 mitochondrial genes. The two taxa have a genetic distance of p = 16.2% based on 12 PCGs, p = 15.3% based on 36 mitochondrial genes, p = 13.1% based on 2 rRNA genes and p = 10.7% based on 22 tRNA genes, indicating status of sibling species. The Costa Rica and Brazil taxa of A. costaricensis are proposed to be accorded specific status as members of a species complex.
    Matched MeSH terms: Phylogeny
  15. Complete mitochondrial genomes of the tooth of a poached Bornean banteng (Bos javanicus lowi; Cetartiodactyla, Bovidae)
    Ishige T, Gakuhari T, Hanzawa K, Kono T, Sunjoto I, Sukor JR, et al.
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016 Jul;27(4):2453-4.
    PMID: 26075477 DOI: 10.3109/19401736.2015.1033694
    Here we report the complete mitochondrial genome of the Bornean banteng Bos javanicus lowi (Cetartiodactyla, Bovidae), which was determined using next-generation sequencing. The mitochondrial genome is 16,344 bp in length containing 13 protein-coding genes, 21 tRNAs and 2 rRNAs. It shows the typical pattern of bovine mitochondrial arrangement. Phylogenetic tree analysis of complete mtDNA sequences showed that Bornean banteng is more closely related to gaur than to other banteng subspecies. Divergence dating indicated that Bornean banteng and gaur diverged from their common ancestor approximately 5.03 million years ago. These results suggest that Bornean banteng might be a distinct species in need of conservation.
    Matched MeSH terms: Phylogeny
  16. Molecular identification and phylogeny of Armillaria isolates from South America and Indo-Malaysia
    Coetzee MP, Wingfield BD, Bloomer P, Ridley GS, Wingfield MJ
    Mycologia, 2003 Mar-Apr;95(2):285-93.
    PMID: 21156614
    Armillaria root rot is a serious disease, chiefly of woody plants, caused by many species of Armillaria that occur in temperate, tropical and subtropical regions of the world. Very little is known about Armillaria in South America and Southeast Asia, although Armillaria root rot is well known in these areas. In this study, we consider previously unidentified isolates collected from trees with symptoms of Armillaria root rot in Chile, Indonesia and Malaysia. In addition, isolates from basidiocarps resembling A. novae-zelandiae and A. limonea, originating from Chile and Argentina, respectively, were included in this study because their true identity has been uncertain. All isolates in this study were compared, based on their similarity in ITS sequences with previously sequenced Armillaria species, and their phylogenetic relationship with species from the Southern Hemisphere was considered. ITS sequence data for Armillaria also were compared with those available at GenBank. Parsimony and distance analyses were conducted to determine the phylogenetic relationships between the unknown isolates and the species that showed high ITS sequence similarity. In addition, IGS-1 sequence data were obtained for some of the species to validate the trees obtained from the ITS data set. Results of this study showed that the ITS sequences of the isolates obtained from basidiocarps resembling A. novae-zelandiae are most similar to those for this species. ITS sequences for isolates from Indonesia and Malaysia had the highest similarity to A. novae-zelandiae but were phylogenetically separated from this species. Isolates from Chile, for which basidiocarps were not found, were similar in their ITS and IGS-1 sequences to the isolate from Argentina that resembled A. limonea. These isolates, however, had the highest ITS and IGS-1 sequence similarity to authentic isolates of A. luteobubalina and were phylogenetically more closely related to this species than to A. limonea.
    Matched MeSH terms: Phylogeny
  17. Fulltext Biotic and abiotic variables influencing plant litter breakdown in streams: a global study
    Boyero L, Pearson RG, Hui C, Gessner MO, Pérez J, Alexandrou MA, et al.
    Proc Biol Sci, 2016 Apr 27;283(1829).
    PMID: 27122551 DOI: 10.1098/rspb.2015.2664
    Plant litter breakdown is a key ecological process in terrestrial and freshwater ecosystems. Streams and rivers, in particular, contribute substantially to global carbon fluxes. However, there is little information available on the relative roles of different drivers of plant litter breakdown in fresh waters, particularly at large scales. We present a global-scale study of litter breakdown in streams to compare the roles of biotic, climatic and other environmental factors on breakdown rates. We conducted an experiment in 24 streams encompassing latitudes from 47.8° N to 42.8° S, using litter mixtures of local species differing in quality and phylogenetic diversity (PD), and alder (Alnus glutinosa) to control for variation in litter traits. Our models revealed that breakdown of alder was driven by climate, with some influence of pH, whereas variation in breakdown of litter mixtures was explained mainly by litter quality and PD. Effects of litter quality and PD and stream pH were more positive at higher temperatures, indicating that different mechanisms may operate at different latitudes. These results reflect global variability caused by multiple factors, but unexplained variance points to the need for expanded global-scale comparisons.
    Matched MeSH terms: Phylogeny
  18. Fulltext Comprehensive genome analysis of a pangolin-associated Paraburkholderia fungorum provides new insights into its secretion systems and virulence
    Tan KY, Dutta A, Tan TK, Hari R, Othman RY, Choo SW
    PeerJ, 2020;8:e9733.
    PMID: 32953261 DOI: 10.7717/peerj.9733
    Background: Paraburkholderia fungorum (P. fungorum) is a Gram-negative environmental species that has been commonly used as a beneficial microorganism in agriculture as an agent for biocontrol and bioremediation. Its use in agriculture is controversial as many people believe that it could harm human health; however, there is no clear evidence to support.

    Methodology: The pangolin P. fungorum (pangolin Pf) genome has a genomic size of approximately 7.7 Mbps with N50 of 69,666 bps. Our study showed that pangolin Pf is a Paraburkholderia fungorum supported by evidence from the core genome SNP-based phylogenetic analysis and the ANI analysis. Functional analysis has shown that the presence of a considerably large number of genes related to stress response, virulence, disease, and defence. Interestingly, we identified different types of secretion systems in the genome of pangolin Pf, which are highly specialized and responsible for a bacterium's response to its environment and in physiological processes such as survival, adhesion, and adaptation. The pangolin Pf also shared some common virulence genes with the known pathogenic member of the Burkholderiales. These genes play important roles in adhesion, motility, and invasion.

    Conclusion: This study may provide better insights into the functions, secretion systems and virulence of this pangolin-associated bacterial strain. The addition of this genome sequence is also important for future comparative analysis and functional work of P. fungorum.

    Matched MeSH terms: Phylogeny
  19. Fulltext Taxonomy and phylogeny of the genus Gastrocentrum Gorham (Coleoptera, Cleridae, Tillinae), with the description of five new species
    Yang G, Yang X, Shi H
    Zookeys, 2020;979:99-132.
    PMID: 33192133 DOI: 10.3897/zookeys.979.53765
    The genus Gastrocentrum Gorham, 1876 is revised to include nine species. Five new species are described in this genus: G. magnumsp. nov. (NE India), G. regularesp. nov. (Cameron Highlands, Malaysia), G. xiaodongisp. nov. (Gyirong, Xizang, China), G. zayuensesp. nov. (Zayü, Xizang, China), and G. gaoligongensesp. nov. (Fugong, Yunnan, China). Gastrocentrum nitidum Schenkling, 1916 is transferred to the genus Tillus as a new combination. All the species in this genus are described (except G. brevicolle), and a key is provided for their identification. Illustrations of male genitalia, female reproductive organs, and other important structures are provided. An interspecific phylogeny-estimate of Gastrocentrum is presented based on morphological data, with two main clades recognized: a clade containing G. unicolor and G. laterimaculatum, and a clade containing the remaining six species (the latter a polytomy consisting of G. magnumsp. nov., G. dux, and G. regularesp. nov., and a well-supported sub-clade representing the remaining species). Additionally, the taxonomic and phylogenetic importance of female reproductive organs is discussed.
    Matched MeSH terms: Phylogeny
  20. Fulltext Geographical structure, narrow species ranges, and Cenozoic diversification in a pantropical clade of epiphyllous leafy liverworts
    Bechteler J, Schäfer-Verwimp A, Lee GE, Feldberg K, Pérez-Escobar OA, Pócs T, et al.
    Ecol Evol, 2017 01;7(2):638-653.
    PMID: 28116059 DOI: 10.1002/ece3.2656
    The evolutionary history and classification of epiphyllous cryptogams are still poorly known. Leptolejeunea is a largely epiphyllous pantropical liverwort genus with about 25 species characterized by deeply bilobed underleaves, elliptic to narrowly obovate leaf lobes, the presence of ocelli, and vegetative reproduction by cladia. Sequences of three chloroplast regions (rbcL, trnL-F, psbA) and the nuclear ribosomal ITS region were obtained for 66 accessions of Leptolejeunea and six outgroup species to explore the phylogeny, divergence times, and ancestral areas of this genus. The phylogeny was estimated using maximum-likelihood and Bayesian inference approaches, and divergence times were estimated with a Bayesian relaxed clock method. Leptolejeunea likely originated in Asia or the Neotropics within a time interval from the Early Eocene to the Late Cretaceous (67.9 Ma, 95% highest posterior density [HPD]: 47.9-93.7). Diversification of the crown group initiated in the Eocene or early Oligocene (38.4 Ma, 95% HPD: 27.2-52.6). Most species clades were established in the Miocene. Leptolejeunea epiphylla and L. schiffneri originated in Asia and colonized African islands during the Plio-Pleistocene. Accessions of supposedly pantropical species are placed in different main clades. Several monophyletic morphospecies exhibit considerable sequence variation related to a geographical pattern. The clear geographic structure of the Leptolejeunea crown group points to evolutionary processes including rare long-distance dispersal and subsequent speciation. Leptolejeunea may have benefitted from the large-scale distribution of humid tropical angiosperm forests in the Eocene.
    Matched MeSH terms: Phylogeny
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