78 research outputs found
Eight new Halophytophthora species from marine and brackish-water ecosystems in Portugal and an updated phylogeny for the genus
During an oomycete survey in December 2015, 10 previously unknown Halophytophthora taxa were isolated from marine and brackish water of tidal ponds and channels in saltmarshes, lagoon ecosystems and river estuaries at seven sites along the Algarve coast in the South of Portugal. Phylogenetic analyses of LSU and ITS datasets, comprising all described Halophytophthora species, the 10 new Halophytophthora taxa and all relevant and distinctive sequences available from GenBank, provided an updated phylogeny of the genus Halophytophthora s.str. showing for the first time a structure of 10 clades designated as Clades 1-10. Nine of the 10 new Halophytophthora taxa resided in Clade 6 together with H. polymorphica and H. vesicula. Based on differences in morphology and temperature-growth relations and a multigene (LSU, ITS, Btub, hsp90, rpl10, tigA, cox1, nadh1, rps10) phylo-geny, eight new Halophytophthora taxa from Portugal are described here as H. brevisporangia, H. cele-ris, H. frigida, H. lateralis, H. lusitanica, H. macrosporangia, H. sinuata and H. thermoambigua. Three species, H. frigida, H. macrosporangia and H. sinuata, have a homothallic breeding system while the remaining five species are sterile. Pathogenicity and litter decomposition tests are underway to clarify their pathological and ecological role in the marine and brackish-water ecosystems. More oomycete surveys in yet undersurveyed regions of the world and population genetic or phylogenomic analyses of global populations are needed to clarify the origin of the new Halophytophthora species.info:eu-repo/semantics/publishedVersio
Development of microsatellite and mating type markers for the pine needle pathogen Lecanosticta acicola
Lecanosticta acicola is an ascomycete that causes brown spot needle blight of pine species
in many regions of the world. This pathogen is responsible for a major disease of Pinus
palustris in the USA and is a quarantine organism in Europe. In order to study the genetic
diversity and patterns of spread of L. acicola, eleven microsatellite markers and two
mating type markers were developed. An enrichment protocol was used to isolate
microsatellite-rich DNA regions and 18 primer pairs were designed to flank these regions,
of which eleven were polymorphic. A total of 93 alleles were obtained across all loci from
forty isolates of L. acicola from the USA with an allelic diversity range of 0.095 to 0.931
per locus. Cross-species amplification with some of the markers was obtained with L.
gloeospora, L. guatemalensis and Dothistroma septosporum, but not with D. pini. Mating
type (MAT) markers amplifying both idiomorphs were also developed to determine mating
type distribution in populations. These markers were designed based on alignments of both
idiomorphs of nine closely related plant pathogens and a protocol for multiplex PCR
amplification of the MAT loci was optimised. The MAT markers are not species specific
and also amplify the MAT loci in Dothistroma septosporum, D. pini, L. gloeospora and L.
guatemalensis. Both types of genetic markers developed in this study will be valuable for
future investigations of the population structure, genetic diversity and invasion history of
L. acicola on a global scale.Financial support to Josef Janoušek from the AKTION Czech Republic – Austria (project 58p23), the Scholarship Foundation of the Republic of Austria (OeAD-GmbH, Austria),theHlavka Foundation (Czech Republic; for internship at Massey University, New Zealand) and the Intern Grant Agency of the Faculty of Forestry and Wood Technology (Mendel University in Brno, Czech Republic).The project was supported financially by COST CZ LD12031 (DIAROD), the FPS COST Action FP1102 (DIAROD) and the European Union’s Seventh Framework Programme FP7 2007–2013 (KBBE 2009–3) under grant agreement 245268 ISEFOR.http://link.springer.com/journal/13313hb201
Population genomics of speciation and admixture
The application of population genomics to the understanding of speciation has led to the emerging field of speciation genomics. This has brought new insight into how divergence builds up within the genome during speciation and is also revealing the extent to which species can continue to exchange genetic material despite reproductive barriers. It is also providing powerful new approaches for linking genotype to phenotype in admixed populations. In this chapter, we give an overview of some of the methods that have been used and some of the novel insights gained. We also outline some of the pitfalls of the most commonly used methods and possible problems with interpretation of the results
Evolution of sex determination and heterogamety changes in section Otites of the genus Silene
Abstract Switches in heterogamety are known to occur in both animals and plants. Although plant sex determination systems probably often evolved more recently than those in several well-studied animals, including mammals, and have had less time for switches to occur, we previously detected a switch in heterogamety in the plant genus Silene: section Otites has both female and male heterogamety, whereas S. latifolia and its close relatives, in a different section of the genus, Melandrium (subgenus Behenantha), all have male heterogamety. Here we analyse the evolution of sex chromosomes in section Otites, which is estimated to have evolved only about 0.55 MYA. Our study confirms female heterogamety in S. otites and newly reveals female heterogamety in S. borysthenica. Sequence analyses and genetic mapping show that the sex-linked regions of these two species are the same, but the region in S. colpophylla, a close relative with male heterogamety, is different. The sex chromosome pairs of S. colpophylla and S. otites each correspond to an autosome of the other species, and both differ from the XY pair in S. latifolia. Silene section Otites species are suitable for detailed studies of the events involved in such changes, and our phylogenetic analysis suggests a possible change from female to male heterogamety within this section. Our analyses suggest a possibility that has so far not been considered, change in heterogamety through hybridization, in which a male-determining chromosome from one species is introgressed into another one, and over-rides its previous sex-determining system
A new approach for enhancing eddy-current non-destructive evaluation
The paper proposes a new approach for enhancing depth evaluation in eddy-current non-destructive testing. A
detected crack is inspected using several probes. The crack’s signals gained using the probes are linearly
superposed and unique feature values of the ratio of superposition are extracted from the resulting signals.
Numerical investigations as well as experimental verification reveal that the feature values provide clear
indication about the depth of the detected crack. In addition, the depth of a defect that is much deeper than the
standard depth of penetration can also be evaluated using the proposed approach
Simultaneous Surgical Repair of Abdominal Aortic Aneurysm Using Fresh Arterial Allograft and Renal Transplantation
Co-Cultivation of Human Aortic Smooth Muscle Cells With Epicardial Adipocytes Affects Their Proliferation Rate
Summary The abnormal proliferation of vascular smooth muscle cells (VSMC) is thought to play a role in the pathogenesis of atherosclerosis. Adipocytes produce several bioactive paracrine substances that can affect the growth and migration of VSMCs. Our study focuses on the direct effect of the bioactive substances in conditioned media (CM) that was obtained by incubation with primary adipocyte-derived cell lines, including cell lines derived from both preadipocytes and from more mature cells, on the proliferation rate of human aortic smooth muscle cells (HAoSMCs). We used a Luminex assay to measure the adipokine content of the CM and showed that there was a highe
Sperm divergence in a passerine contact zone: Indication of reinforcement at the gametic level
Simultaneous Surgical Repair of Abdominal Aortic Aneurysm Using Fresh Arterial Allograft and Renal Transplantation
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