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Registros recuperados: 176 | |
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Torres García, Jesús Rubén. |
Las malezas compiten intensamente con los cultivos, por lo cual, los agricultores emplean prácticas de control (manual, mecánico y químico) para eliminarlas. Los herbicidas ejercen una presión de selección extrema (99.99%) sobre las poblaciones. Como consecuencia, en unas pocas generaciones se observan individuos resistentes (R) en las poblaciones de maleza. La resistencia a herbicidas es un proceso evolutivo causado por cambios metabólicos o genéticos. En algunas especies la resistencia va acompañada de una disminución en la aptitud competitiva (fitness). Esto puede ocasionar que las plantas resistentes sean desplazadas cuando el factor de selección se retire de las poblaciones. Phalaris minor (Poaceae) es una maleza que evolucionó hacia la adquisición de... |
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Palavras-chave: Fitness; Costo de la resistencia; Evolución; Ecología evolutiva; Doctorado; Botánica; Cost of resistance; Evolution; Evolutionary ecology. |
Ano: 2012 |
URL: http://hdl.handle.net/10521/1778 |
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Ruiz,Eduardo; Toro,Oscar; Crawford,Daniel J; Stuessy,Tod F; Negritto,María A; Baeza,Carlos; Becerra,José. |
Phylogenetic relationships among Chilean species of Drimys as well asD. granadensis from Central America andD. angustifolia from Brazil were reconstructed using internal transcribed spacers (ITS) of nuclear ribosomal DNA and a parsimony analysis. Our results at the family level were congruent with previous phylogenetic hypotheses. Molecular data indicate that the Juan Fernandez Island endemic D. confertifolia diverged early in the evolution of the genus, and it is not closely related to the continental species D. winteri, as might be expected on the basis of morphology and biogeography. The ITS phytogeny also provides general support for a recent distribution of species on the western side of the Andes Mountains; the only exception is D. andina, which may... |
Tipo: Journal article |
Palavras-chave: Drimys; Evolution; ITS; Indels; Winteraceae. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432008000200008 |
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Loss-Morais,Guilherme; Turchetto-Zolet,Andreia Carina; Etges,Matheus; Cagliari,Alexandro; Körbes,Ana Paula; Maraschin,Felipe dos Santos; Margis-Pinheiro,Márcia; Margis,Rogério. |
Ribosome-inactivating proteins (RIPs) are enzymes that inhibit protein synthesis after depurination of a specific adenine in rRNA. The RIP family members are classified as type I RIPs that contain an RNA-N-glycosidase domain and type II RIPs that contain a lectin domain (B chain) in addition to the glycosidase domain (A chain). In this work, we identified 30 new plant RIPs and characterized 18 Ricinus communis RIPs. Phylogenetic and functional divergence analyses indicated that the emergence of type I and II RIPs probably occurred before the monocot/eudicot split. We also report the expression profiles of 18 castor bean genes, including those for ricin and agglutinin, in five seed stages as assessed by quantitative PCR. Ricin and agglutinin were the most... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agglutinin; Evolution; Lipase; Ricinus communis; Ricin; RIPs. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572013000100011 |
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Lanna,Emilio. |
The non-bilaterian animals comprise organisms in the phyla Porifera, Cnidaria, Ctenophora and Placozoa. These early-diverging phyla are pivotal to understanding the evolution of bilaterian animals. After the exponential increase in research in evolutionary development (evo-devo) in the last two decades, these organisms are again in the spotlight of evolutionary biology. In this work, I briefly review some aspects of the developmental biology of nonbilaterians that contribute to understanding the evolution of development and of the metazoans. The evolution of the developmental genetic toolkit, embryonic polarization, the origin of gastrulation and mesodermal cells, and the origin of neural cells are discussed. The possibility that germline and stem cell... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Early-diverging metazoans; BMP; FGF; Wnt; Stem cells; Evolution; Nervous system. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572015000300284 |
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Viscardi,Lucas Henriques; Paixão-Côrtes,Vanessa Rodrigues; Comas,David; Salzano,Francisco Mauro; Rovaris,Diego; Bau,Claiton Dotto; Amorim,Carlos Eduardo G.; Bortolini,Maria Cátira. |
Abstract Hominin evolution is characterized by adaptive solutions often rooted in behavioral and cognitive changes. If balancing selection had an important and long-lasting impact on the evolution of these traits, it can be hypothesized that genes associated with them should carry an excess of shared polymorphisms (trans- SNPs) across recent Homo species. In this study, we investigate the role of balancing selection in human evolution using available exomes from modern (Homo sapiens) and archaic humans (H. neanderthalensis and Denisovan) for an excess of trans-SNP in two gene sets: one associated with the immune system (IMMS) and another one with behavioral system (BEHS). We identified a significant excess of trans-SNPs in IMMS (N=547), of which six of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Human behavior; Evolution; Balancing selection; Immune genes; Behavioral genes. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000100067 |
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Carvalho,Margarida Lima; Oliveira,Claudio; Foresti,Fausto. |
The family Gasteropelecidae is composed of three genera and eight species. This study shows that Thoracocharax cf. stellatus has 2n = 52 chromosomes for both sexes. The five males studied showed 8 metacentric, 16 submetacentric, 4 subtelocentric, and 24 acrocentric chromosomes; the seven females showed only one submetacentric chromosome, belonging to pair 11, and one extra acrocentric chromosome, smaller than all the other chromosomes, characterizing the presence of a ZZ/ZW sex chromosome system in this species. Nucleolus organizing regions (NORs) were detected on the short arms of the subtelocentric chromosome pair 13. Constitutive heterochromatin was identified at pericentromeric and terminal positions in almost all chromosomes. The W chromosome was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sex chromosomes; ZW; DNA content; Fish; Evolution. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000300008 |
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Santos,Vanessa; Almeida,Cícero. |
Abstract This study reports the complete chloroplast sequences of three Spondias species. The genome sequences were obtained for Spondias tuberosa, Spondias bahienses, and Spondias mombin using the Illumina sequencing technology by a combination of de novo methods and a reference-guided assembly using Sapindus mukorossi as reference. The genomes of S. tuberosa, S. bahiensis, and S. mombin had 162,036, 162,218, and 162,302 bp, respectively. The coding regions exhibited 130 genes, including 34–35 tRNAs and 4 rRNAs. The results revealed synteny among the genomes, with high conservation in the gene order and content and CG content. The inverted repeat regions (IRA and IRB) and the large and small single copies were very similar among the three genomes. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Plastome; Evolution; Spondias. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000100132 |
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Souza,Marcelo Santos de; Barcellos,Suziane Alves; Costa,Alice Lemos; Kretschmer,Rafael; Garnero,Analía Del Valle; Gunski,Ricardo José. |
Abstract The Passeriformes is the most diverse and cytogenetically well-known clade of birds, comprising approximately 5,000 species. The sooty-fronted spinetail (Synallaxis frontalis Aves: Furnariidae) species, which belongs to the order Passeriformes, is typically found in South America, where it is widely distributed. Polymorphisms provide genetic variability, important for several evolutionary processes, including speciation and adaptation to the environment. The aim of this work was to analyze the possible cytotypes and systemic events involved in the species polymorphism. Of the sampled 19 individuals, two thirds were polymorphic, an event supposedly linked to mutations resulting from genomic evolution that can be transmitted hereditarily. A... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomal polymorphism; Evolution; Cytogenetics. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572019000100062 |
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Domingues,Alayne Magalhães Trindade; Waldschmidt,Ana Maria; Andrade,Sintia Emmanuelle; Andrade-Souza,Vanderly; Alves,Rogério Marco de Oliveira; Silva Junior,Juvenal Cordeiro da; Costa,Marco Antônio. |
Although many species of the genus Trigona have been taxonomically described, cytogenetic studies of these species are still rare. The aim of the present study was to obtain cytogenetic data by conventional staining, C banding and fluorochrome staining for the karyotype characterization of the species Trigona fulviventris. Cytogenetic analysis revealed that this species possesses a diploid chromosome number of 2n = 32, different from most other species of this genus studied so far. This variation was probably due to the centric fusion in a higher numbered ancestral karyotype, this fusion producing the large metacentric chromosome pair and the lower chromosome number observed in Trigona fulviventris. Heterochromatin was detected in the pericentromeric... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Cytogenetics; Heterochromatin; Evolution; Stingless bees. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000300009 |
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Nobre,Lydayanne Lilás de Melo; Santos,José Daniel Oliveira dos; Leite,Rychard; Almeida,Cícero. |
Abstract The genus Spondias (family Anacardiaceae) comprises 19 taxa, ten of which occur in Neotropical regions. Spondias bahiensis has been suggested to be a hybrid, although initial evidence does not support this hypothesis. The aim of this study was to test the hypothesis of the hybrid origin of S. bahiensis using high-throughput sequencing with single nucleotide polymorphism (SNP) analysis, characterization of intragenomic nuclear ribosomal DNA (nrDNA), and nuclear and chloroplast phylogenomic analyses. The SNP analysis revealed a high number of SNPs in the S. bahiensis genome, and with respect to nrDNA, S. bahiensis shared approximately half of the SNP alleles with S. tuberosa, but not with S. mombin. Combining the SNP analysis with nrDNA phylogeny... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: RDNA; Phylogenetics; Evolution; Hybrid offspring. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572018000500878 |
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Singarete,Marina E.; Grizante,Mariana B.; Milograna,Sarah R.; Nery,Mariana F.; Kin,Koryu; Wagner,Günter P.; Kohlsdorf,Tiana. |
Developmental processes and their results, morphological characters, are inherited through transmission of genes regulating development. While there is ample evidence that cis-regulatory elements tend to be modular, with sequence segments dedicated to different roles, the situation for proteins is less clear, being particularly complex for transcription factors with multiple functions. Some motifs mediating protein-protein interactions may be exclusive to particular developmental roles, but it is also possible that motifs are mostly shared among different processes. Here we focus on HoxA13, a protein essential for limb development. We asked whether the HoxA13 amino acid sequence evolved similarly in three limbless clades: Gymnophiona, Amphisbaenia and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Development; Evolution; HoxA13; Molecular signatures; Limblessness. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572015000300255 |
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Santos,Carlos A.F.; Simon,Philipp W.. |
Amplified fragment length polymorphism (AFLP) is a fast and reliable tool to generate a large number of DNA markers. In two unrelated F2 populations of carrot (Daucus carota L.), Brasilia x HCM and B493 x QAL (wild carrot), it was hypothesized that DNA 1) digested with the same restriction endonuclease enzymes and amplified with the same primer combination and 2) sharing the same position in polyacrylamide gels should be conserved sequences. To test this hypothesis AFLP fragments from polyacrylamide gels were eluted, reamplified, separated in agarose gels, purified, cloned and sequenced. Among thirty-one paired fragments from each F2 population, twenty-six had identity greater than 91% and five presented identity of 24% to 44%. Among the twenty-six... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Daucus carota; Evolution; Molecular markers; SCAR. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000200013 |
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Registros recuperados: 176 | |
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