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61.
Pavel Trávní?ek Jana Jersáková Barbora Kubátová Jana Krej?íková Richard M. Bateman Magdalena Lu?anová Eva Krajníková Tamara Tě?itelová Zuzana ?típková Jean-Pierre Amardeilh Emilia Brzosko Edyta Jermakowicz Olivier Cabanne Walter Durka Peter Efimov Mikael Hedrén Carlos E. Hermosilla Karel Kreutz Tiiu Kull Kadri Tali Olivier Marchand Manel Rey Florian P. Schiestl Vladislav ?urn Jan Suda 《Annals of botany》2012,110(5):977-986
Background and Aims
Patterns of ploidy variation among and within populations can provide valuable insights into the evolutionary mechanisms shaping the dynamics of plant systems showing ploidy diversity. Whereas data on majority ploidies are, by definition, often sufficiently extensive, much less is known about the incidence and evolutionary role of minority cytotypes.Methods
Ploidy and proportions of endoreplicated genome were determined using DAPI (4'',6-diamidino-2-phenylindole) flow cytometry in 6150 Gymnadenia plants (fragrant orchids) collected from 141 populations in 17 European countries. All widely recognized European species, and several taxa of less certain taxonomic status were sampled within Gymnadenia conopsea sensu lato.Key Results
Most Gymnadenia populations were taxonomically and/or ploidy heterogeneous. Two majority (2x and 4x) and three minority (3x, 5x and 6x) cytotypes were identified. Evolution largely proceeded at the diploid level, whereas tetraploids were much more geographically and taxonomically restricted. Although minority ploidies constituted <2 % of the individuals sampled, they were found in 35 % of populations across the entire area investigated. The amount of nuclear DNA, together with the level of progressively partial endoreplication, separated all Gymnadenia species currently widely recognized in Europe.Conclusions
Despite their low frequency, minority cytotypes substantially increase intraspecific and intrapopulation ploidy diversity estimates for fragrant orchids. The cytogenetic structure of Gymnadenia populations is remarkably dynamic and shaped by multiple evolutionary mechanisms, including both the ongoing production of unreduced gametes and heteroploid hybridization. Overall, it is likely that the level of ploidy heterogeneity experienced by most plant species/populations is currently underestimated; intensive sampling is necessary to obtain a holistic picture. 相似文献62.
Ott Scheler Barry Glynn Sven Parkel Priit Palta Kadri Toome Lauris Kaplinski Maido Remm Majella Maher Ants Kurg 《BMC biotechnology》2009,9(1):45-6
Background
Here we present a novel promising microbial diagnostic method that combines the sensitivity of Nucleic Acid Sequence Based Amplification (NASBA) with the high information content of microarray technology for the detection of bacterial tmRNA molecules. The NASBA protocol was modified to include aminoallyl-UTP (aaUTP) molecules that were incorporated into nascent RNA during the NASBA reaction. Post-amplification labeling with fluorescent dye was carried out subsequently and tmRNA hybridization signal intensities were measured using microarray technology. Significant optimization of the labeled NASBA protocol was required to maintain the required sensitivity of the reactions. 相似文献63.
64.
Jakobson I Peusha H Timofejeva L Järve K 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(4):760-769
In the progeny of a cross between the common wheat cultivar Tähti and Triticum militinae, a member of the timopheevii group of tetraploid wheats, several hybrid lines were selected that are characterized by improved seedling and adult plant resistance (APR) to powdery mildew. An F2 single-seed descendant mapping population segregating for seedling resistance and APR to powdery mildew was analysed for the identification of quantitative trait loci (QTL). The main QTL responsible for APR was detected on the long arm of chromosome 4A tightly linked to the Xgwm160 locus on a T. militinae translocation explaining up to 54% of phenotypic variance. The same translocation influenced seedling resistance to powdery mildew upon inoculation of plants with a synthetic population of Blumeria graminis DC. f. sp. tritici, and explained 28–33% of the phenotypic variance. 相似文献
65.
Sylvia Cremer Line V. Ugelvig Falko P. Drijfhout Birgit C. Schlick-Steiner Florian M. Steiner Bernhard Seifert David P. Hughes Andreas Schulz Klaus S. Petersen Heino Konrad Christian Stauffer Kadri Kiran Xavier Espadaler Patrizia d'Ettorre Nihat Akta? J?rgen Eilenberg Graeme R. Jones David R. Nash Jes S. Pedersen Jacobus J. Boomsma 《PloS one》2008,3(12)
It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects. 相似文献
66.
67.
Lauris Kaplinski Ott Scheler Sven Parkel Priit Palta Kadri Toome Ants Kurg Maido Remm 《BMC biotechnology》2010,10(1):34
Background
The hybridization of synthetic Streptococcus pneumoniae tmRNA on a detection microarray is slow at 34°C resulting in low signal intensities. 相似文献68.
Anna Delprato Yasmine Al Kadri Natacha Pérébaskine Cécile Monfoulet Yves Henry Anthony K. Henras Sébastien Fribourg 《Nucleic acids research》2014,42(15):10161-10172
The essential Rcl1p and Bms1p proteins form a complex required for 40S ribosomal subunit maturation. Bms1p is a GTPase and Rcl1p has been proposed to catalyse the endonucleolytic cleavage at site A2 separating the pre-40S and pre-60S maturation pathways. We determined the 2.0 Å crystal structure of Bms1p associated with Rcl1p. We demonstrate that Rcl1p nuclear import depends on Bms1p and that the two proteins are loaded into pre-ribosomes at a similar stage of the maturation pathway and remain present within pre-ribosomes after cleavage at A2. Importantly, GTP binding to Bms1p is not required for the import in the nucleus nor for the incorporation of Rcl1p into pre-ribosomes, but is essential for early pre-rRNA processing. We propose that GTP binding to Bms1p and/or GTP hydrolysis may induce conformational rearrangements within the Bms1p-Rcl1p complex allowing the interaction of Rcl1p with its RNA substrate. 相似文献
69.
Three new species of ants (genus <Emphasis Type="Italic">Aphaenogaster</Emphasis>, Hymenoptera: Formicidae) from Turkey 总被引:1,自引:0,他引:1
Three new species of the ant genus Aphaenogaster (A. aktaci sp. n., A. maculifrons sp. n., A. radchenkoi sp. n.) are described from Turkey and their taxonomic positions are discussed. Aphaenogaster aktaci sp. n. belongs to the obsidiana group, A. maculifrons sp. n. to subterranea group and A. radchenkoi sp. n. to pallida group of the Attomyrma subgenus. Key characteristics for identification of the species and data on their ecology are given. 相似文献
70.
Fifteen patients having total occlusion of the proximal left anterior descending coronary artery were studied. All fifteen had normal left ventricular anterior walls. The electrocardiogram was normal in eight patients; old inferior wall infarction was evident in one; anterior ischemia in five; and left anterior hemiblock in one. Collateral circulation was found in twelve patients (80%). These findings suggest that an angiographically non-visualized left anterior descending (LAD) vessel is patent and bypassable in patients where the anterior ventricular wall is intact, thus representing an additional criterion for aortocoronary bypass surgery. 相似文献