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排序方式: 共有727条查询结果,搜索用时 31 毫秒
711.
Clérison R. Perini Verónica I. Sosa Vicente E. Koda Horacio Silva Andrés A. Risso Wanessa N. F. Vasconcelos Carolina F. Gonçalves Gustavo A. Ugalde Dayanna N. Machado Caroline B. Bevilacqua Daniel M. P. Ardisson-Araújo Kevin Maebe Guy Smagghe Ivair Valmorbida Jerson C. Guedes 《Agricultural and Forest Entomology》2021,23(3):250-260
- The Plusiinae subfamily has many polyphagous species, many of which occur in South America. Chrysodeixis includens and Rachiplusia nu are two representatives that mainly occurs in soybeans, cotton, common beans, sunflower and alfalfa.
- A population genetic study of C. includens and R. nu collected in the Southern Cone of America was performed using a partial COI gene sequencing data and compared with specimens from other American countries.
- Six haplotypes were identified in C. includens populations of Brazil, Argentina, Paraguay and Uruguay, organized within a star-like haplotype network, with the most common haplotype identified as Chin_MC.
- R. nu populations are more diverse and stable in comparison to C. includens. Populations from Argentina and Uruguay had the highest haplotype diversity, sharing five haplotypes and putatively indicating haplotype exchange.
- Demographic change analysis suggested a recent population expansion of C. includens over the American continent.
- Some C. includens haplotypes were country-specific, suggesting population expansion in the countries where specimens were collected.
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DNA methylation of embryogenic carrot cell cultures and its variations as caused by mutation,differentiation, hormones and hypomethylating drugs 总被引:7,自引:0,他引:7
F. LoSchiavo L. Pitto G. Giuliano G. Torti V. Nuti-Ronchi D. Marazziti R. Vergara S. Orselli M. Terzi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,77(3):325-331
Summary The level of auxin - both natural and synthetic — in the medium has a strong effect on the level of 5-methyl-cytosine in the DNA of carrot cells in culture. This level may vary from approximately 15% to 70% of total cytosine without apparent effects on growth rate and cell morphology. No effect was seen with cytokinin. During somatic embryogenesis, in the absence of hormones, variations were seen in the level of methylation according to a characteristic pattern. If hypomethylation is induced with drugs such as azacytidine, ethionine or ethoxy-carbonyl-pyrimidine, embryogenesis is immediately blocked. A mutant was isolated which is resistant to the action of hypomethylating drugs. It shows variations in the methylation pattern and variations in indole-acetic acid metabolism. In addition its regeneration is often associated with the production of tumors.Deceased 相似文献
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Almanza-Alcalde Horacio Satyal Poshendra Corbera Esteve SotoSánchez Alma Patricia Pskowski Martha 《Human ecology: an interdisciplinary journal》2022,50(1):79-90
Human Ecology - Since 2007 many developing countries have laid groundwork for Reducing Emissions from Deforestation and forest Degradation and sustainable management and conservation of forests... 相似文献
718.
Molecular and plumage analyses indicate the incomplete separation of two woodpeckers (Aves,Picidae)
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Larissa Sampaio Alexandre Aleixo Horacio Schneider Iracilda Sampaio Juliana Araripe Péricles Sena do Rêgo 《Zoologica scripta》2018,47(4):418-427
We evaluated the relationship between Celeus undatus and Celeus grammicus, with the objective of clarifying their evolutionary history. We analysed fragments of the mitochondrial and nuclear genes of 57 specimens. For comparative purposes, we inspected the plumage patterns of 77 skins. Our findings highlight the absence of reciprocal monophyly between the two taxa, given their reduced genetic divergence, and the lack of any clear separation of the two forms in the haplotype networks. A similar situation was found in the STRUCTURE analysis, with reciprocal contributions from the two taxa to the respective clusters, indicating that C. grammicus and C. undatus cannot be differentiated using the molecular markers. Corroborating the genetic data, our plumage analyses also failed to find any clear diagnostic characters between the polytypic C. undatus and C. grammicus, as they are defined at present. The genetic profile is consistent with either extensive historical gene flow between the species or, alternatively, incomplete lineage sorting, rather than recent secondary contact. The lack of monophyly between the two taxa impeded subspecies‐level phylogeographic inferences, with the subspecific variation being interpreted as a probable artefact of the phenotypic plasticity of the two forms. These findings indicate clearly that the two taxa form a single evolutionary unit, in which the morphological differentiation used to diagnose the species, combined with their geographic distribution, is at odds with the incomplete separation of the taxa. This may reflect disparities in the rates of differentiation between molecular and phenotypic markers, which is possibly due to the variation in selection pressures along a humidity gradient in Amazonia. 相似文献
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Ol’ha O. Brovarets’ Ivan S. Voiteshenko Horacio Pérez-Sánchez Dmytro M. Hovorun 《Journal of biomolecular structure & dynamics》2018,36(7):1649-1665
This work is devoted to the careful QM/QTAIM analysis of the evolution of the basic physico-chemical parameters along the intrinsic reaction coordinate (IRC) of the biologically important 2AP·T(WC)?2AP·T*(w) and 2AP·C*(WC)?2AP·C(w) Watson–Crick(WC)?wobble(w) tautomeric transformations obtained at each point of the IRC using original authors’ methodology. Established profiles reflect the high similarity between the courses of these processes. Basing on the scrupulous analysis of the profiles of their geometric and electron-topological parameters, it was established that the dipole-active WC?w tautomerizations of the Watson–Crick-like 2AP·T(WC)/2AP·C*(WC) mispairs, stabilized by the two classical N3H?N1, N2H?O2 and one weak C6H?O4/N4 H-bonds, into the wobble 2AP·T*(w)/2AP·C(w) base pairs, respectively, joined by the two classical N2H?N3 and O4/N4H?N1 H-bonds, proceed via the concerted stepwise mechanism through the sequential intrapair proton transfer and subsequent large-scale shifting of the bases relative each other, through the planar, highly stable, zwitterionic transition states stabilized by the participation of the four H-bonds – N1+H?O4–/N4–, N1+H?N3–, N2+H?N3–, and N2+H?O2–. Moreover, it was found out that the 2AP·T(WC)?2AP·T*(w)/2AP·C*(WC)?2AP·C(w) tautomerization reactions occur non-dissociatively and are accompanied by the consequent replacement of the 10 unique patterns of the specific intermolecular interactions along the IRC. Obtained data are of paramount importance in view of their possible application for the control and management of the proton transfer, e.g. by external electric or laser fields. 相似文献