Mutagênese em Petunia x hybrida Vilm. e isolamento de um novo mutante morfológico

Traditionally, mutagenesis has been used to introduce novel genetic variability in ornamental crops. More recently, it has become a powerful tool in gene discovery and functional analyses in reverse genetics approaches. The present work aimed to compare the efficiency of physical and chemical agents in generating mutant populations of petunia. We have indirectly evaluated the genomic damage by analyzing developmental characteristics of the plantlets derived from treated seeds employing gamma radiation at 0, 20, 40, 60, 80 and 100 Gy and the alkylating agent ethyl-methanesulfonate (EMS) at 0, 0.05, 0.1, 0.15, 0.2 and 0.25% (v/v). Gamma rays and EMS caused developmental defects and decreased seedling viability in plants obtained from the mutagenized seeds. High mutagen doses reduced in approximately 44% the number of plants with primary leaves at 15 days after sowing (DAS) and decreased seedling survival rates to 55% (gamma) and 28% (EMS), in comparison to untreated controls. Seedling height decrease was proportional to increasing EMS dosage, whereas 40 and 60 Gy of gamma irradiation caused the most significant reduction in height. Moderate DNA damage allowing a high saturation of mutant alleles in the genome and the generation of viable plants for reverse genetics studies was correlated to the biological parameter LD50, the dose required to kill half of the tested population. It corresponded to 100 Gy for gamma radiation and 0.1% for EMS treatment. The optimized mutagen treatments were used to develop petunia mutant populations (M1 and M2) and novel morphological mutants were identified.A mutagênese tem sido tradicionalmente usada para gerar variabilidade genética em plantas ornamentais. Recentemente, tornou-se uma ferramenta poderosa na descoberta e análise da função gênica em genética reversa. Este trabalho objetivou comparar a eficiência da mutagênese física e química na geração de populações mutantes de petúnia. O dano genômico foi avaliado indiretamente por características de desenvolvimento de plântulas após o tratamento com doses de radiação gama de 0, 20, 40, 60, 80 e 100 Gy e do agente alquilante etil-metanossulfonato (EMS) de 0; 0,05; 0,1; 0,15; 0,2 e 0,25% (v/v). Radiação gama e EMS causaram danos ao desenvolvimento e reduziram a viabilidade das plântulas derivadas das sementes tratadas. As maiores doses de mutagênico diminuíram o número de plantas com folhas primárias aos 15 dias após a semeadura (DAS) em aproximadamente 44% e reduziram as taxas de sobrevivência a 55% (gama) e 28% (EMS) em relação aos controles. A redução na altura das plântulas foi proporcional ao aumento das dosagens de EMS, enquanto 40 e 60 Gy de radiação gama provocaram a redução mais significativa na altura de plantas. Abordagens de genética reversa requerem danos genômicos moderados, que permitam alta saturação de alelos mutantes com pequena redução no número de plantas viáveis, relacionados ao parâmetro biológico DL50, dosagem de mutagênico necessária para eliminar metade da população. Este valor correspondeu a 100 Gy de radiação gama e 0,1% de EMS. Os tratamentos foram empregados para a geração de populações mutantes de petúnia (M1 e M2) e novos mutantes morfológicos foram isolados.FAPES

Assessing the Role of Carbonyl Adducts, Particularly Malondialdehyde Adducts, in the Development of Dermis Yellowing Occurring during Skin Photoaging

Solar elastosis is associated with a diffuse yellow hue of the skin. Photoaging is related to lipid peroxidation leading to the formation of carbonyl groups. Protein carbonylation can occur by addition of reactive aldehydes, such as malondialdehyde (MDA), 4-hydroxy-nonenal (4-HNE), and acrolein. All the proteins concerned with this modification, and the biological consequences of adduct formation, are not completely identified. The link between yellowish skin and dermal carbonylated proteins induced by aldehyde adducts was investigated. The study was carried out on ex vivo skin samples from sun-exposed or sun-protected areas and on in vitro dermal equivalent models incubated with 5 mM MDA, 4-HNE, or acrolein. The yellow color and the level of MDA, 4-HNE, and acrolein adducts were evaluated. Yellowish color differences were detected in the dermis of sun-exposed skin compared to sun-protected skin and in in vitro models following addition of MDA, 4-HNE, or acrolein. The yellowing was correlated with the carbonyl adducts increasing in the dermis and in in vitro models incubated with aldehydes. The stronger yellowing seemed to be mediated more by MDA than 4-HNE and acrolein. These observations suggest that dermal carbonylation especially induced by MDA result in the yellow hue of dermis and is involved, in part, in the yellowing observed during skin photoaging

Genetic diversity in soybean germplasm identified by SSR and EST-SSR markers.

Os objetivos deste trabalho foram avaliar a diversidade genética de 79 acessos de soja de diferentes regiões do mundo, agrupá-los de acordo com a similaridade e testar a correlação entre os dois tipos de marcadores utilizados. Foram utilizados marcadores microssatélites genômicos (SSR) e funcionais (EST-SSR). Trinta pares de primers SSR foram selecionados (20 genômicos e 10 EST-SSR) de acordo com sua distribuição nos 20 grupos de ligação da soja, com sua unidade de repetição trinucleotídica e com seu conteúdo de informação polimórfica. Todos os lócus analisados foram polimórficos, e 259 alelos foram encontrados. O número de alelos por lócus variou entre 2?21, com média de 8,63. Os acessos possuem uma quantidade significativa de alelos raros, sendo os acessos 19, 35, 63 e 65 os que apresentaram maior número de alelos exclusivos. Os acessos 75 e 79 são os mais similares e os acessos 31 e 35, e 40 e 78 são os mais divergentes. Foi observada baixa correlação entre resultados de SSR e EST-SSR. Portanto, uma análise adequada de diversidade em soja deve ser feita utilizando-se tanto marcadores microssatélites genômicos como funcionais. A diversidade genética dos acessos selecionados é alta, tendo sido encontrados cinco grupos e vários subgrupos. Observou-se moderada relação entre divergência genética e origem geográfica dos acessos

Neurofilaments in motor neuron disorders: towards promising diagnostic and prognostic biomarkers

Motor neuron diseases (MNDs) are etiologically and biologically heterogeneous diseases. The pathobiology of motor neuron degeneration is still largely unknown, and no effective therapy is available. Heterogeneity and lack of specific disease biomarkers have been appointed as leading reasons for past clinical trial failure, and biomarker discovery is pivotal in today’s MND research agenda. In the last decade, neurofilaments (NFs) have emerged as promising biomarkers for the clinical assessment of neurodegeneration. NFs are scaffolding proteins with predominant structural functions contributing to the axonal cytoskeleton of myelinated axons. NFs are released in CSF and peripheral blood as a consequence of axonal degeneration, irrespective of the primary causal event. Due to the current availability of highly-sensitive automated technologies capable of precisely quantify proteins in biofluids in the femtomolar range, it is now possible to reliably measure NFs not only in CSF but also in blood. In this review, we will discuss how NFs are impacting research and clinical management in ALS and other MNDs. Besides contributing to the diagnosis at early stages by differentiating between MNDs with different clinical evolution and severity, NFs may provide a useful tool for the early enrolment of patients in clinical trials. Due to their stability across the disease, NFs convey prognostic information and, on a larger scale, help to stratify patients in homogenous groups. Shortcomings of NFs assessment in biofluids will also be discussed according to the available literature in the attempt to predict the most appropriate use of the biomarker in the MND clinic

The landscape of cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis

Although mutations in the superoxide dismutase 1 gene account for only a minority of total amyotrophic lateral sclerosis cases, the discovery of this gene has been crucial for amyotrophic lateral sclerosis research. Since the identification of superoxide dismutase 1 in 1993, the field of amyotrophic lateral sclerosis genetics has considerably widened, improving our understanding of the diverse pathogenic basis of amyotrophic lateral sclerosis. In this review, we focus on cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis patients. Literature has mostly reported that cognition remains intact in superoxide dismutase 1-amyotrophic lateral sclerosis patients, but recent reports highlight frontal lobe function frailty in patients carrying different superoxide dismutase 1-amyotrophic lateral sclerosis mutations. We thoroughly reviewed all the various mutations reported in the literature to contribute to a comprehensive database of superoxide dismutase 1-amyotrophic lateral sclerosis genotype-phenotype correlation. Such a resource could ultimately improve our mechanistic understanding of amyotrophic lateral sclerosis, enabling a more robust assessment of how the amyotrophic lateral sclerosis phenotype responds to different variants across genes, which is important for the therapeutic strategy targeting genetic mutations. Cognition in superoxide dismutase 1-amyotrophic lateral sclerosis deserves further longitudinal research since this peculiar frailty in patients with similar mutations can be conditioned by external factors, including environment and other unidentified agents including modifier genes

Unraveling the variability and genetic structure of barker frog Physalaemus Cuvieri(Leiuperinae) populations from different regions of Brazil

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORThe barker frog Physalaemus cuvieri is widely distributed in South America and is found in all regions of Brazil. Significant intraspecific morphological variation in this species has been reported. To determine the genetic structure of the natural Brazilian populations of P. cuvieri, 10 different populations geographically separated by 99.41 to 2936.75 km were evaluated using 10 polymorphic microsatellite loci. In addition, mitochondrial DNA data were analyzed to determine genetic distance between the populations. The genetic variation was found to be significant in most of the populations (HE ranged from 0.40 to 0.59, and allelic richness ranged from 2.07 to 3.54). An FST value of 0.27 indicated that high genetic structure was present among the P. cuvieri populations. STRUCTURE analyses grouped the 10 populations into nine clusters and indicated that only two of the populations were not genetically differentiated. The genetic distance calculated from the mitochondrial DNA data showed values <0.03 for seven of the populations.The barker frog Physalaemus cuvieriis widely distributed in South America and is found in all regions of Brazil. Significant intraspecific morphological variation in this species has been reported. To determine the genetic structure of the natural Brazili13380558065FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR06/59697-7sem informaçã

Study Of Closely Related Species Within The Physalaemus Cuvieri Group (anura): Contribution Of Microsatellite Markers.

Various species of the Physalaemus cuvieri group of frogs are difficult to distinguish morphologically, making molecular analysis an attractive alternative for indentifying members of this group, which is considered to be at risk because of loss of habitat. The genetic structure of natural populations of P. ephippifer and P. albonotatus species was investigated and analyzed, together with that of five previously studied populations of P. cuvieri. Nine microsatellite loci were used in the analyses. The overall G(ST) value (0.46) revealed high genetic variation among the populations, as expected for different species. Bayesian analysis implemented by the STRUCTURE software clustered the seven populations into seven groups (K = 7). All the P. albonotatus and P. ephippifer specimens were grouped into a single cluster, both species showing clear differentiation from P. cuvieri. The different grouping based on these microsatellites of some P. cuvieri individuals from Porto Nacional and from Passo Fundo suggests that they could be a new species, indicating a necessity for taxonomic reevaluation. Despite the intrinsic difficulties in analyzing closely related species, the nine microsatellite loci were found to be adequate for distinguishing these three species of the P. cuvieri group and their populations.101434-4

Population structures of Brazilian tall coconut ( Cocos nuciferaL.) by microsatellite markers.

In this study we investigated the genetic diversity of 10 populations of Brazilian Tall coconut trees, employing 13 SSR loci to characterize their genetic variability, population structure, and reproductive system

Genetic structure and molecular variability of Spodoptera frugiperda (Lepidoptera: Noctuidae) collected in maize and cotton fields in Brazil

The purpose of this research was to evaluate the genetic similarity and structure of the fall armyworm, Spodoptera frugiperda (J.E. Smith), populations associated with maize and cotton crops in Brazil using amplified fragment length polymorphisms. Mean genetic similarity among populations was 0.45. The unweighted pair group method with arithmetic mean analysis dendrograms did not separate populations of S. frugiperda into clusters related to the host plant in which the insects were collected. No genetic variation was observed among maize and cotton populations of S. frugiperda, suggesting that the same populations are injuring both crops in Brazil. This research validates the need for stewardship of crop-protection methods for managing S. frugiperda to reduce the incidence of pesticide resistance, due to the spatial and temporal overlapping of maize and cotton crops in some regions in Brazil