Home About us Contact
|
Home About us Contact | ||
|
|
||
Taxonomic Relationships (taxonomic + relationships)
Selected AbstractsMolecular heterogeneity in Yersinia enterocolitica and ,Y. enterocolitica -like' species , Implications for epidemiology, typing and taxonomyFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2005Jugsharan S. Virdi Abstract Yersinia enterocolitica is an extremely heterogeneous species. Serotyping and biotyping have been used extensively, in the past, to study its heterogeneity and epidemiology. Application of methods like ribotyping, pulsed-field gel electrophoresis and a host of other genomic techniques have further revealed molecular heterogeneity in this species. Furthermore, these methods may be used effectively to supplement serotyping and biotyping schema for studying epidemiology of Y. enterocolitica. This is evident from the ability of some of these methods to subtype strains belonging to serogroups O:3, O:9 and O:8 , which are most commonly encountered in human Yersiniosis. Multilocus enzyme electrophoresis and nucleotide sequencing have reiterated the taxonomic relationships of this organism. However there is paucity of information about the molecular heterogeneity of ,Y. enterocolitica -like' species, which need to be addressed in the future. Also, newer techniques such as amplified fragment length polymorphism, VNTR-based typing and multilocus sequence typing should be applied to further understand epidemiology, population structure and evolutionary genetics of Y. enterocolitica and ,Y. enterocolitica -like' species. [source] Assessing the health of European rivers using functional ecological guilds of fish communities: standardising species classification and approaches to metric selectionFISHERIES MANAGEMENT & ECOLOGY, Issue 6 2007R. A. A. NOBLE Abstract, The functional ecological guild approach is the cornerstone for the development of Indices of Biotic Integrity and multi-metric indices to assess the ecological status of aquatic systems. These indices combine metrics (unit-specific measures of a functional component of the fish community known to respond to degradation) into a single measure of ecological assessment. The guild approach provides an operational unit linking individual species characteristics with the community as a whole. Species are grouped into guilds based on some degree of overlap in their ecological niches, regardless of taxonomic relationships. Despite European fish species having been classified into ecological guilds, classification has not been standardised Europe-wide or within the context of classifying species into guilds from which metrics can be developed for ecological assessment purposes. This paper examines the approach used by the EU project FAME to classify European fish species into consistent ecological guilds and to identify suitable metrics as basic tools for the development of a standardised ecological assessment method for European rivers to meet the requirements of the Water Framework Directive. [source] Complete sequences of small acid-soluble proteins from Bacillus globigiiJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 10 2004Jeffrey R. Whiteaker Abstract Three abundant small acid-soluble proteins (SASPs) from spores of Bacillus globigii were sequenced using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with post-source decay and nanoelectrospray collision-induced dissociation tandem mass spectrometry. The proteins were extracted from spores with 1 M HCl. Scanning electron micrographs of spores before and after acid extraction show that the spores retain their overall structure but have a shriveled texture following the acid treatment. Extracted SASPs were purified by high-performance liquid chromatography and molecular masses of the SASPs were identified at 7068 (SASP-1), 7332 (SASP-2), and 8889 (,-SASP). De novo peptide sequencing was used to determine the protein sequences. The correct ordering of peptide sequences was aided by mapping overlapping enzymatic digests and by comparison with homologous SASPs from Bacillus stearothermophilus. B. globigii is used in many field tests as a surrogate for B. anthracis. Thus complete SASP sequences from B. globigii will facilitate the development of methods for rapid identification of bacteria based on mass spectrometry and the examination of taxonomic relationships between Bacillus species. Copyright © 2004 John Wiley & Sons, Ltd. [source] 135 Life History and Ecology of Trentepohliaceae (Chlorophyta) in the West of IrelandJOURNAL OF PHYCOLOGY, Issue 2003F. Rindi Species of subaerial green algae of the family Trentepohliaceae are common in tropical and temperate regions. Despite nearly two centuries of investigations, several important aspects of their biology (such as life history and taxonomic relationships of some species) are still poorly understood. In western Ireland, the abundance of Trentepohliaceae is a peculiar feature of the subaerial algal vegetation. Six species are present (Phycopeltis arundinacea, Printzina lagenifera, Trentepohlia abietina, T. aurea, T. iolithus and T. umbrina). Life history and phenology of these were examined by extensive field and culture studies. In contrast to most other subaerial algae, the Trentepohliaceae show a generally strict substratum-specificity in western Ireland. T. iolithus, in particular, is remarkable for its occurrence on concrete walls, where it may produce extensive dark-red growths. Our observations suggest that general statements about the life history of Trentepohlia should be reconsidered critically. There is no evidence that in Irish populations a regular alternation of isomorphic gametophytes and sporophytes takes place; biflagellate swarmers (usually considered gametes) behave as asexual spores and reproduce the same morphological phase. No fusion of gametes was observed and a detailed examination of the literature concerning the genus shows that this phenomenon is extremely rare. A combination of studies based on different types of data (molecular data, examination of very large numbers of field samples, chromosome numbers, culture studies) is considered fundamental to any definitive clarification of the taxonomy and life history of Trentepohlia. [source] Molecular identification of some forensically important blowflies of southern Africa and AustraliaMEDICAL AND VETERINARY ENTOMOLOGY, Issue 4 2003M. L. Harvey Abstract., One major aspect of research in forensic entomology is the investigation of molecular techniques for the accurate identification of insects. Studies to date have addressed the corpse fauna of many geographical regions, but generally neglected the southern African calliphorid species. In this study, forensically significant calliphorids from South Africa, Swaziland, Botswana and Zimbabwe and Australia were sequenced over an 1167 base pair region of the COI gene. Phylogenetic analysis was performed to examine the ability of the region to resolve species identities and taxonomic relationships between species. Analyses by neighbour-joining, maximum parsimony and maximum likelihood methods all showed the potential of this region to provide the necessary species-level identifications for application to post-mortem interval (PMI) estimation; however, higher level taxonomic relationships did vary according to method of analysis. Intraspecific variation was also considered in relation to determining suitable maximum levels of variation to be expected during analysis. Individuals of some species in the study represented populations from both South Africa and the east coast of Australia, yet maximum intraspecific variation over this gene region was calculated at 0.8%, with minimum interspecific variation at 3%, indicating distinct ranges of variation to be expected at intra- and interspecific levels. This region therefore appears to provide southern African forensic entomologists with a new technique for providing accurate identification for application to estimation of PMI. [source] Dichotrachelus kahleni sp. n., a new weevil species from the Carnian Alps, north-eastern Italy (Coleoptera, Curculionidae, Entiminae)MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 2 2007Massimo Meregalli Abstract A new species of Dichotrachelus is described from the Carnian Alps, Friuli-Venezia Giulia, north-eastern Italy (type locality: Moggio Udinese, Mount Sernio). The new species belongs to the D. luzei species group, previously known from Mt. Pasubio, Veneto, and Mt. Grintavec, Slovenia; its discovery in the Carnian Alps fills thus a broad gap in the distribution of this group. It is associated with Saxifraga caesia in limestone habitats; imagoes, apparently hatching in late summer, live in the small clumps of the host plants; some larvae were found among the roots. Additional specimens moderately distinct were found in the Julian Alps: taxonomic relationships between these and the type specimens of D. kahleni are discussed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Historical male-mediated introgression in horseshoe bats revealed by multilocus DNA sequence dataMOLECULAR ECOLOGY, Issue 7 2010XIUGUANG MAO Abstract Instances of hybridization between mammalian taxa in the wild are rarely documented. To test for introgression between sibling species of horseshoe bat (Rhinolophus yunanensis and R. pearsoni) and two subspecies of the latter (R. p. pearsoni and R. p. chinensis), we sequenced two mtDNA and two ncDNA markers in individuals sampled from multiple localities within their overlapping ranges. The interspecific mtDNA gene tree corresponded to the expected taxonomic divisions, and coalescent-based analyses suggested divergence occurred around 4 MYA. However, these relationships strongly conflicted with those recovered from two independent nuclear gene trees, in which R. yunanensis clustered with R. p. pearsoni to the exclusion of R. p. chinensis. This geographically widespread discordance is best explained by large-scale historical introgression of ncDNA from R. yunanensis to R. pearsoni by male-mediated exchange in mixed species colonies during Pleistocene glacial periods, when ranges may have contracted and overlapped more than at present. Further species tree,gene tree conflicts were detected between R. p. pearsoni and R. p. chinensis, also indicating past and/or current introgression in their overlapping regions. However, here the patterns point to asymmetric mtDNA introgression without ncDNA introgression. Analyses of coalescence times indicate this exchange has occurred subsequent to the divergence of these subspecies from their common ancestor. Our work highlights the importance of using multiple data sets for reconstructing phylogeographic histories and resolving taxonomic relationships. [source] Microsatellite loci isolated from the Caribbean coral, Montastraea annularisMOLECULAR ECOLOGY RESOURCES, Issue 1 2004E. G. Severance Abstract We report the isolation and characterization of seven microsatellite loci from the Caribbean reef-building coral, Montastraea annularis. All loci are polymorphic with allele numbers ranging from five to 31 and observed heterozygosities from 0.17 to 0.89. These loci can be used in assessing gene flow patterns and diversity of this stony coral species both for local coral reef management purposes as well as for elucidating population connectivity within the greater Caribbean basin. These markers should also be applicable to other species of Montastraea and for resolving taxonomic relationships within the M. annularis species complex. [source] The fruit fly fauna (Diptera: Tephritidae: Dacinae) of Bougainville, the Solomon Islands and VanuatuAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 2 2001Richard Ai Drew Abstract The Bougainville, Solomon Islands and Vanuatu dacine fauna is revised and 12 new species are described: Bactrocera atrabifasciata, B. fuscipennula, B. hamaceki, B. hollingsworthi, B. naucleae, B. neoxanthodes, B. obliquivenosa, B. pacificae, B. parafroggatti, B. peneobscura, B. unitaeniola, Dacus taui. Two new synonymies are established: Bactrocera honiarae Drew = Bactrocera confluens (Drew); Dacus varipes Malloch = Bactrocera quadrisetosa (Bezzi). Information is given on attractant records, geographical distributions and taxonomic relationships. A key to species is also provided. [source] Taxonomical, nomenclatural and biogeographical revelations in the Zamia skinneri complex of Central America (Cycadales: Zamiaceae)BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2008ALBERTO S. TAYLOR B. Evidence is provided substantiating (1) a more taxonomically sound application of the name Zamia skinneri Warsz. ex A.Dietr. to populations of green-emergent, plicate-leaved plants from coastal mainland Bocas del Toro, Panama and (2) the lack of a formal name for the red-emergent, plicate-leaved plants from north-central Panama. Re-characterization of Z. skinneri is followed by a discussion of the status of Z. neurophyllidia D.W.Stev. and formal descriptions of three endemic, arborescent, plicate-leaved cycads from northwestern and central Atlantic Panama: Z. hamannii sp. nov., Z. imperialis sp. nov. and Z. nesophila sp. nov. Also included is a brief discussion of taxonomic relationships within the group, a key to the plicate-leaved cycads of Panama and a hypothesis for the historical biogeography and evolution of the skinneri complex. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 399,429. [source] | ||||||||||||||||||||||