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BERNARD SLIPPERS TREENA BURGESS BRENDA D. WINGFIELD PEDRO W. CROUS TERESA A. COUTINHO MICHAEL J. WINGFIELD 《Molecular ecology resources》2004,4(4):675-677
We report the development of eight sets of microsatellite markers for the ascomycete fungus and tree pathogen, Botryosphaeria parva. The primers were identified after cloning and sequencing of fragments amplified using simple sequence repeat (SSR) primers. Genome walking was used to determine unknown sequences on either side of new SSRs. The primers were tested and proved useful in nine other Botryosphaeria species that all have Fusicoccum anamorphs, similar to B. parva. 相似文献
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Moral status is a vexing topic. Linked for so long to the unending debates about ensoulment and the morality of abortion, it has recently resurfaced in the embryonic stem cell controversy. In this new context, it should benefit from new insights originating in recent scientific advances. We believe that the recently observed capability of somatic cells to return to a pluripotential state (a capability we propose to name 'reversed potency') in a controlled manner requires us to modify the traditional concept of moral status and to consider it as referring not only to intrinsic properties (like 'to possess reason' or 'to be a person'), but also to extrinsic or relational ones. 相似文献
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by MARC PHILIPPE JEAN-PAUL BILLON-BRUYAT† JOSE C. GARCIA-RAMOS‡ LOÏC BOCAT† BERNARD GOMEZ LAURA PIÑUELA‡ 《Palaeontology》2010,53(1):201-214
Abstract: Previously known from the Kimmeridgian–Portlandian of Dorset (UK) only, Protocupressinoxylon purbeckensis wood is reported here from the Kimmeridgian of Asturias (Spain) and Ajoie (Switzerland). The morphospecies taxonomy and nomenclature are discussed, and new supplementary illustrations are given. The P. purbeckensis tree was growing in dry strongly seasonal (tropophilous) environments, and the new occurrences suggest that such a climate prevailed on land all over southwestern Europe at the end of the Jurassic (Kimmeridgian sensu anglico – Portlandian). The review of fossil wood data indicates that such a stressful environment may have constrained terrestrial biocoenoses and their evolution at the Jurassic/Cretaceous boundary. But wood generic diversity curves are also strikingly similar to that drawn 20 years ago for nonmarine tetrapods, implying a fossil Lagerstätte effect. 相似文献
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BERNARD MICHAUX 《Biological journal of the Linnean Society. Linnean Society of London》2010,101(1):193-212
The concepts of biogeographical regions and areas of endemism are briefly reviewed prior to a discussion of what constitutes a natural biogeographical unit. It is concluded that a natural biogeographical unit comprises a group of endemic species that share a geological history. These natural biogeographical units are termed Wallacean biogeographical units in honour of the biogeographer A.R. Wallace. Models of the geological development of Indonesia and the Philippines are outlined. Areas of endemism within Wallacea are identified by distributional data, and their relationship to each other and to the adjacent continental regions are evaluated using molecular phylogenies from the literature. The boundaries of these areas of endemism are in broad agreement with earlier works, but it is argued that the Tanimbar Islands are biologically part of south Maluku, rather than the Lesser Sundas, and that Timor (plus Savu, Roti, Wetar, Damar, and Babar) and the western Lesser Sundas form areas of endemism in their own right. Wallacean biogeographical units within Wallacea are identified by congruence between areas of endemism and geological history. It is concluded that although Wallacea as a whole is not a natural biogeographical region, neither is it completely artificial as it is formed from a complex of predominantly Australasian exotic fragments linked by geological processes within a complex collision zone. The Philippines are argued to be an integral part of Wallacea, as originally intended. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 193–212. 相似文献
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BUTLER DECLAN M.; ?STGAARD KJETILL; BOYEN CATHERINE; EVANS LEONARD V.; JENSEN ARNE; KLOAREG BERNARD 《Journal of experimental botany》1989,40(11):1237-1246
In an investigation of the main factors determining protoplastyield in Laminaria saccharina and L. digitata, protoplasts wereisolated from epidermal, cortical and medullary cells of vegetativethallus by incubation with commercial cellulases, crude andpurified mannuronate lyases and purified guluronate lyases.Treatment of the tissue with the calcium chelator EGTA beforeenzymatic digestion greatly increased the protoplast yield.Preplasmolysis was also necessary to obtain large numbers ofhealthy protoplasts and this was most effective when carriedout during chelation with EGTA. Purification of the mannuronatelyases by ion exchange chromatography reduced the toxicity ofthe crude enzyme preparation. The activities of the wall degradingenzymes were differentially influenced by pH and the optimumfor alginate-lyase activity (8.0) was higher than that for cellulaseactivity (<6.0). Protoplast yield decreased linearly withincreasing pH in the enzyme medium over the range tested (6.08.0),and this suggests that cellulases are more critical to walldigestion than alginate-lyases. Ionic osmotica gave improvedyields compared with sugar alcohols or sugars. Increasing thecalcium concentration of the enzyme medium brought about anexponential decrease in protoplast yield and wall digestionwas almost completely inhibited at concentrations exceeding8.0 mol m3. However, low levels of calcium (<2.0 molm3) were beneficial to protoplast viability. Yields of107 to 108 protoplasts g1 fr. wt. were consistently obtainedand 20% to 30% of these regenerated new cell walls within 12d of culture. Key words: Laminaria protoplasts, cell wall, alginate-lyases 相似文献
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