231 research outputs found

    Burying behaviour in the bobtail squid Sepiola atlantica (Cephalopoda: Sepiolidae)

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    5 páginas, 1 figura, 1 tablaThe burying behavioural pattern of the small Atlantic bobtail squid (Sepiola atlantica) in natural substrate is described, quantitatively differentiating the movements in different phases and the chromatic changes associated with this behaviour. All specimens showed the same two-part sequence of burying, which triggered a display of colour changes peculiar to this species. Our results suggested that this was a consistent behaviour during burial. The mean latency time in the alert posture was 9.55 ± 5.49 s. The mean duration of the first phase was 12.2 ± 4.37 s. The mean duration of the second phase was 10.2 ± 2.95 s. The average time spent completing the behavioural pattern was 21.9 ± 4.93 s. Burying time was not related to size. Differences observed between individuals were associated with the number of movements in each phase. However, these movements were not significantly related to the size of the animals. A comparison of the burying pattern of this species with other members of the family Sepiolidae is madePeer reviewe

    Parâmetros morfométricos e desempenho fotossintético de abacaxis propagados in vitro

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    Pineapple (Ananas comosus) is a horticultural species of the Bromeliaceae family of high socioeconomic interest, widely cultivated around the world. The multiplication of pineapple seedlings in the field can be time-consuming, requiring a significant labor investment. The objective of this study was to evaluate the performance of continuous and temporary immersion systems in the micropropagation scale-up of the species. Shoots were obtained from explants subcultured in flasks with gelled culture medium and without gas exchange. The shoots were transferred to liquid MS medium supplemented with 2mM NAA, and 4mM BAP, and cultivated in four different devices: sealed flasks, flasks with semipermeable gas membranes, RITA®, and twin-flasks. After 45 days of cultivation, plant growth, fresh mass increment, the stomatal density of the abaxial surface of the leaves, the maximum quantum yield of the photosystem II, and contents of chlorophyll and carotenoids were analyzed. Significant differences were observed in plant growth, stomatal density, and contents of chlorophyll and carotenoids. The twin-flasks and RITA® devices revealed better results in morphological parameters, such as plant growth and stomatal density, while the treatments in sealed flasks and with membrane stood out in the chlorophyll content.O abacaxi (Ananas comosus) é uma espécie hortícola da família Bromeliaceae de alto interesse socioeconômico, amplamente cultivada em todo o mundo. A multiplicação de mudas de abacaxi no campo pode ser demorada, exigindo um investimento significativo de mão-de-obra. O objetivo deste estudo foi avaliar o desempenho de sistemas de imersão contínua e temporária na ampliação da escala de micropropagação da espécie. As brotações foram obtidas de explantes sub-cultivados em frascos com meio de cultura gelificado e sem troca gasosa. Os brotos foram transferidos para meio líquido MS suplementado com 2mM ANA e 4mM BAP e cultivados em quatro diferentes dispositivos: frascos selados, frascos com membranas gasosas semipermeáveis, RITA® e frascos duplos. Após 45 dias de cultivo, foram analisados o crescimento das plantas, o incremento de massa fresca, a densidade estomática da superfície abaxial das folhas, o rendimento quântico máximo do fotossistema II e os teores de clorofila e carotenoides. Diferenças significativas foram observadas no crescimento das plantas, densidade estomática e teores de clorofila e carotenóides. Os frascos duplos e os dispositivos RITA® revelaram resultados superiores em parâmetros morfológicos, como crescimento vegetal e densidade estomática, enquanto os tratamentos em frascos selados e com membrana se destacaram no teor de clorofila.Facultad de Ciencias Agrarias y Forestale

    The karyotype of Nothoscordum arenarium Herter (Gilliesioideae, Alliaceae): A populational and cytomolecular analysis

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    The genus Nothoscordum Kunth comprises approximately 20 species native to South America. Karyologically, the genus is remarkable for its large chromosomes and Robertsonian translocations. Variation in chromosome number has been recorded in a few polyploid species and it is unknown among diploids. This study presents the chromosome number and morphology of 53 individuals of seven populations of N. arenarium Herter (2n = 10). In addition, karyotype analyses after C-banding, staining with CMA and DAPI, and in situ hybridization with 5S and 45S rDNA probes were performed in six individuals from one population. All individuals exhibited 2n = 10 (6M + 4A), except for one tetraploid (2n = 20, 12M + 8A) and one triploid (2n = 15, 9M + 6A) plant. C-banding revealed the presence of CMA+ /DAPI - heterochromatin in the short arm and in the proximal region of the long arm of all acrocentric chromosomes. The 45S rDNA sites co-localized with the CMA + regions of the acrocentrics short arms, while the 5S rDNA probe only hybridized with the subterminal region of a pair of metacentric chromosomes. A change in the pattern of CMA bands and rDNA sites was observed in only one individual bearing a reciprocal translocation involving the long arm of a metacentric and the long arm of an acrocentric chromosome. These data suggest that, despite isolated cases of polyploidy and translocation, the karyotype of N. arenarium is very stable and the karyotypic instability described for other species may be associated with their polyploid condition

    Identification and characterization of Tc1/mariner-like DNA transposons in genomes of the pathogenic fungi of the Paracoccidioides species complex

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    <p>Abstract</p> <p>Background</p> <p><it>Paracoccidioides brasiliensis </it>(Eukaryota, Fungi, Ascomycota) is a thermodimorphic fungus, the etiological agent of paracoccidioidomycosis, the most important systemic mycoses in Latin America. Three isolates corresponding to distinct phylogenetic lineages of the <it>Paracoccidioides </it>species complex had their genomes sequenced. In this study the identification and characterization of class II transposable elements in the genomes of these fungi was carried out.</p> <p>Results</p> <p>A genomic survey for DNA transposons in the sequence assemblies of <it>Paracoccidioides</it>, a genus recently proposed to encompass species <it>P. brasiliensis </it>(harboring phylogenetic lineages S1, PS2, PS3) and <it>P. lutzii </it>(<it>Pb01-like </it>isolates), has been completed. Eight new <it>Tc1/mariner </it>families, referred to as Trem (<b>Tr</b>ansposable <b>e</b>lement <b>m</b>ariner), labeled A through H were identified. Elements from each family have 65-80% sequence similarity with other <it>Tc1/mariner </it>elements. They are flanked by 2-bp TA target site duplications and different termini. Encoded DDD-transposases, some of which have complete ORFs, indicated that they could be functionally active. The distribution of Trem elements varied between the genomic sequences characterized as belonging to <it>P. brasiliensis </it>(S1 and PS2) and <it>P. lutzii</it>. TremC and H elements would have been present in a hypothetical ancestor common to <it>P. brasiliensis </it>and <it>P. lutzii</it>, while TremA, B and F elements were either acquired by <it>P. brasiliensis </it>or lost by <it>P. lutzii </it>after speciation. Although TremD and TremE share about 70% similarity, they are specific to <it>P. brasiliensis </it>and <it>P. lutzii</it>, respectively. This suggests that these elements could either have been present in a hypothetical common ancestor and have evolved divergently after the split between <it>P. brasiliensis </it>and <it>P. Lutzii</it>, or have been independently acquired by horizontal transfer.</p> <p>Conclusions</p> <p>New families of <it>Tc1/mariner </it>DNA transposons in the genomic assemblies of the <it>Paracoccidioides </it>species complex are described. Families were distinguished based on significant BLAST identities between transposases and/or TIRs. The expansion of Trem in a putative ancestor common to the species <it>P. brasiliensis </it>and <it>P. lutzii </it>would have given origin to TremC and TremH, while other elements could have been acquired or lost after speciation had occurred. The results may contribute to our understanding of the organization and architecture of genomes in the genus <it>Paracoccidioides</it>.</p

    Antimicrobial, Antiproliferative and Proapoptotic Activities of Extract, Fractions and Isolated Compounds from the Stem of Erythroxylum caatingae Plowman

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    In the study, we have examined the antitumor and antimicrobial activities of the methanol extract, the fractions, a fraction of total alkaloids and two alkaloids isolated from the stem of Erythroxylum caatingae Plowman. All test fractions, except the hexane fractions, showed antimicrobial activity on gram-positive bacteria and fungi. The acetate: methanol (95:5), acetate, chloroform and hexane fractions show the highest cytotoxicity activity against the NCI-H292, HEp-2 and K562 cell lines using MTT. The absence of hemolysis in the erythrocytes of mice was observed in these fractions and 6β-Benzoyloxy-3α-(3,4,5- trimethoxybenzoyloxy) tropane (catuabine B). Staining with Annexin V-FITC and JC-1 was used to verify the mechanism of action of the compounds of E. caatingae that showed cytotoxicity less than 30 μg/mL in leukemic cells. After 48 h of incubation, we observed that the acetate: methanol (95:5), acetate, and chloroform fractions, as well as the catuabine B, increased in the number of cells in early apoptosis, from 53.0 to 74.8%. An analysis of the potential of the mitochondrial membrane by incorporation of JC-1 showed that most cells during incubation of the acetate: methanol (95:5) and acetate fractions (63.85 and 59.2%) were stained, suggesting the involvement of an intrinsic pathway of apoptosis

    Karyotype differentiation in three species of Tripogandra Raf. (Commelinaceae) with different ploidy levels

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    Most species of the genus Tripogandra (Commelinaceae) are taxonomically poorly circumscribed, in spite of having a relatively stable basic number x = 8. Aiming to estimate the cytological variation among Tripogandra species carrying this base number, several structural karyotypic characters were investigated in the diploid T. glandulosa, the hexaploid T. serrulata, and the octoploid T. diuretica. A careful evaluation of chromosome size and morphology did not reveal clear chromosome homeologies among karyotypes. The mean chromosome size was strongly reduced in the octoploid species, but not in the hexaploid species. They also differed largely in the CMA+ banding pattern and in the number of 5S and 45S rDNA sites per monoploid chromosome complement. All three species showed proximal DAPI + heterochromatin, although in T. serrulata this kind of heterochromatin was only visible after FISH. Further, the meiosis in T. serrulata was highly irregular, suggesting that this species has a hybrid origin. The data indicate that, in spite of the conservation of the base number, these species are karyologically quite different from each other

    Dietary sulfur amino acid restriction upregulates DICER to confer beneficial effects

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    Dietary restriction (DR) improves health and prolongs lifespan in part by upregulating type III endoribonuclease DICER in adipose tissue. In this study, we aimed to specifically test which missing dietary component was responsible for DICER upregulation. Methods: We performed a nutrient screen in mouse preadipocytes and validated the results in vivo using different kinds of dietary interventions in wild type or genetically modified mice and worms, also testing the requirement of DICER on the effects of the diets. Results: We found that sulfur amino acid restriction (i.e., methionine or cysteine) is sufficient to increase Dicer mRNA expression in preadipocytes. Consistently, while DR increases DICER expression in adipose tissue of mice, this effect is blunted by supplementation of the diet with methionine, cysteine, or casein, but not with a lipid or carbohydrate source. Accordingly, dietary methionine or protein restriction mirrors the effects of DR. These changes are associated with alterations in serum adiponectin. We also found that DICER controls and is controlled by adiponectin. In mice, DICER plays a role in methionine restriction-induced upregulation of Ucpl in adipose tissue. In C. elegans, DR and a model of methionine restriction also promote DICER expression in the intestine (an analog of the adipose tissue) and prolong lifespan in a DICER-dependent manner. Conclusions: We propose an evolutionary conserved mechanism in which dietary sulfur amino acid restriction upregulates DICER levels in adipose tissue leading to beneficial health effects29124135CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP305069/2015-2; 304995/2014-288887.143923/2017-002017/01184-9; 2017/07975-8; 2017/22057-5; 2015/03292-8; 2012/07259-7; 2016/02207-0; 2010/52557-0; 2015/01316-7; 2012/50558-5; 2015/19530-5We thank Elzira Elisabeth Saviani and Emanoel Cabral for valuable technical support. We thank the National Institute of Science and Technology on Photonics Applied to Cell Biology (INFABIC) at the Universidade Estadual de Campinas to provide access to microscopes, the Caenorhabditis Genetics Center (CGC) for worms and Dr. Amy Pasquinelli for the dcr-1 RNAi clone. CGC is funded by NIH Office of Research Infrastructure Programs ( P40 OD010440 ). We thank Carmen Perrone for sharing the composition of the methionine restriction diet, for valuable discussion and for sharing samples of rats exposed to methionine restriction. This study was funded by grants of the Fundação de Amparo à Pesquisa do Estado de São Paulo ( 2017/01184-9 , 2017/07975-8 , 2017/22057-5 , 2015/03292-8 , 2012/07259-7 , 2016/02207-0 , 2010/52557-0 , 2015/01316-7 , 2012/50558-5 and 2015/19530-5 ), Conselho Nacional de Desenvolvimento Científico e Tecnológico ( 305069/2015-2 and 304995/2014-2 ) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - German Academic Exchange Service ( PROBRAL - 88887.143923/2017-00 )

    Entomopathogenic nematology in Latin America: A brief history, current research and future prospects

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    Since the 1980s, research into entomopathogenic nematodes (EPNs) in Latin America has produced many remarkable discoveries. In fact, 16 out of the 117 recognized species of EPNs have been recovered and described in the subcontinent, with many more endemic species and/or strains remaining to be discovered and identified. In addition, from an applied perspective, numerous technological innovations have been accomplished in relation to their implementation in biocontrol. EPNs have been evaluated against over 170 species of agricultural and urban insects, mites, and plant-parasitic nematodes under laboratory and field conditions. While much success has been recorded, many accomplishments remain obscure, due to their publication in non-English journals, thesis dissertations, conference proceedings, and other non-readily available sources. The present review provides a brief history of EPNs in Latin America, including current findings and future perspectives.Fil: San Blas, Ernesto. Instituto Venezolano de Investigaciones Científicas; VenezuelaFil: Campos Herrera, Raquel. Consejo Superior de Investigaciones Científicas; EspañaFil: Dolinski, Claudia. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; BrasilFil: Monteiro, Caio. Universidade Federal de Goiás; BrasilFil: Andaló, Vanessa. Universidade Federal de Uberlandia; BrasilFil: Leite, Luis Garrigós. Universidade Estadual de Campinas; BrasilFil: Rodríguez, Mayra G.. Centro Nacional de Sanidad Agropecuaria; CubaFil: Morales Montero, Patricia. Instituto Venezolano de Investigaciones Científicas; VenezuelaFil: Sáenz Aponte, Adriana. Pontificia Universidad Javeriana; ColombiaFil: Cedano, Carolina. Universidad Nacional de Trujillo; PerúFil: López Nuñez, Juan Carlos. Centro Nacional de Investigaciones del Café; ColombiaFil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Doucet, Marcelo Edmundo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Lax, Paola. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Navarro, Patricia D.. Instituto de Investigaciones Agropecuarias; ChileFil: Báez, Francisco. Instituto Nacional Autonomo de Investigaciones Agropecuarias; EcuadorFil: Llumiquinga, Pablo. Instituto Nacional Autonomo de Investigaciones Agropecuarias; EcuadorFil: Ruiz Vega, Jaime. Instituto Politécnico Nacional ; MéxicoFil: Guerra Moreno, Abby. Laboratorio de Biotecnología; PanamáFil: Stock, S. Patricia. University of Arizona; Estados Unido
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