인공고관절의 세라믹 볼 헤드의 기계적 안정성 평가를 위한 3 차원 유한요소 해석

Advanced Statistical Methods in Biometric Research.

Mitochondrial DNA (mtDNA) sequences were used to infer the phylogenetic relationships of Prochilodus species in the Parana, Amazonas, Orinoco, and Magdalena basins. Sequences of ATPase subunits 6 and 8 (total 840 bp) were obtained for 21 Prochilodus specimens from the four river systems. Using Semaprochilodus as an outgroup, phylogenetic analyses showed that: (i) each river basin contains a monophyletic group of mtDNA lineages; and (ii) the branching order places Magdalena in a basal position with subsequent branching of Orinoco, Amazon and Parana. The mitochondrial control region was sequenced for 26 P. lineatus (from the Parana basin) and six other Prochilodus specimens from the Magdalena, Orinoco and Amazon. All 26 control region haplotypes were unique with sequence divergence ranging from 0.3 to 3.6%. The control region phylogeny is well resolved but phylogenetic structure is not associated with geography. For example, mtDNA haplotypes from the upper Parana (Mogui Guassu) and the upper Bermejo, separated by at least 2600 km, have close genealogical ties. Phylogeographic analyses, including nested clade analysis, suggest high levels of gene flow within this basin.

Population structure and biogeography of migratory freshwater fishes (Prochilodus: Characiformes) in major South American rivers.

Epigenome manipulation as a pathway to new natural product scaffolds and their congeners

Laboratory Protocols CIMMYT Applied Molecular Genetics Laboratory

Os estudos dos metabolitos secundarios de plantas se desenvolveram aceleradamente nos ultimos 50 anos. Estes compostos sao conhecidos por desempenharem um papel importante na adaptacao das plantas aos seus ambientes e tambem representam uma fonte importante de substâncias farmacologicamente ativas. As tecnicas de cultura de celulas de plantas iniciaramse na decada de 1960 como uma possivel ferramenta para estudar e produzir os metabolitos secundarios de plantas. O uso de cultura de celulas de planta para a producao de substâncias de interesse contribuiu grandemente para avancos em diversas areas da fisiologia e bioquimica vegetal. Diferentes estrategias, usando sistemas de cultura in vitro, foram estudadas com o objetivo de aumentar a producao de metabolitos secundarios. As plantas dos generos Aspidosperma e Tabernaemontana sao importantes fontes de alcaloides indolicos biologicamente ativos, sendo que no Brasil existe um numero consideravel de especies destes generos. As culturas de celulas de Aspidosperma e Tabernaemontana foram iniciadas ha pelo menos 16 anos, as quais produzem um grande numero de alcaloides, o que estimulou o desenvolvimento de diversas tecnicas para sua producao, extracao e identificacao.

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Produção de metabólitos secundários em cultura de células e tecidos de plantas: o exemplo dos gêneros Tabernaemontana e Aspidosperma

Cereus peruvianus seedlings were used as a source of stem explants to determine the effective conditions for inducing and maintaining callus tissues in a state of rapid growth, as well as to obtain plants regenerated from callus cultures. Factorial combinations of 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin in MS medium were tested, and we concluded that the 18.1µM 2,4-D and 18.6 or 27.9µM kinetin combinations were suitable for callus induction. The cactus shoots were produced from the friable callus; root elongation occurred within 2 wk in medium without 2,4-D and with 18.6µM kinetin. This method can be used to rapidly produce manyC. peruvianus plants.

In vitro propagation ofCereus peruvianus mill. (cactaceae)

The genetic variability of the "curimba", Prochilodus lineatus, from three locations in the Parana river basin, was investigated by starch gel electrophoresis. A total of 160 specimens were analyzed for 19 enzymes, 12 of which permitted successful interpretation of electrophoretic patterns. Eighteen loci were identified and six of them proved to be polymorphic (EST-1*, EST-2*, IDH-1*, PGM-1*, PGM-2*, LDH-2*). Mean heterozygosity was considered high (13%) by comparison with the literature. A low level of differentiation was found among subpopulations, with mean FST = 0.018. Values of genetic distance and genetic identity suggest that, at least along this stretch of the river, P. lineatus comprises a single breed with high gene flow. This analysis has important implications for fishery management, aquaculture, and conservation of the stocks

Genetic variability of Prochilodus lineatus (Characiformes, Prochilodontidae) in the upper Paraná river

Currently,Cereus peruvianus plants can be rapidly clonedin vitro via adventitious organogenesis using callus cultures; however, somaclonal variation is a problem. A method is described herein using lateral bud explants to produce multiple shoots for clonal propagation. Apical and lateral explants were cultured on MS (Murashige and Skoog, 1962) media with factorial combinations of the auxins indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (NAA), and cytokinins 6-ben-zyladenine (BA) and N-(2-furanyl-methyl)-1-purine-6 amine (kinetin) at the concentrations 0.0, 0.01, 0.1, 1.0 mg“l−1. Positive results were obtained from the lateral explants in all conditions tested, but apical explants did not respond toin vitro multiplication ofC. peruvianus cactus at all growth regulator combinations tested. Formation of axillary shoots inC. peruvianus seems most frequent in medium containing BA at 1.0 mg·l−1 (4.44 μM) and IAA or NAA at 1.0 mg·l−1 (5.71 μM or 5.37 μM respectively), but the frequency of shoot formation in the BA or kinetin and NAA or IAA combinations indicated that any of the combinations tested can be used for multiplication ofC. peruvianus plants regenerated from callus tissue culture. Root formation occurred in all (100%) of the cactus shoots after 9 wk in the same culture medium. All the cacti that developed at the different auxin and cytokin combinations continued growth after transfer to a potting mix of red earth (Paleudult) and ground river sand (1∶1).

Micropropagation of Cereus peruvianus mill. (cactaceae) by areole activation

The morphologically undifferentiated cells of nonregenerant callous tissue of Cereus peruvianus cultured in the original medium and in medium supplemented with tyrosine were used as an alkaloid source. Comparison of alkaloid production by C. peruvianus plants and by callous tissues indicated that alkaloid levels were almost twice as high in callous tissues as in shoots of C. peruvianus plants. The ratio of alkaloid concentration between mature plant and morphologically undifferentiated cells of callous tissue was 1:1.7. A relationship between culture medium containing tyrosine and alkaloid production was also observed in the callous tissues of C. peruvianus. Since increased alkaloid production may be induced by additional factors such as tyrosine, increasing levels of tyrosine or other conditions of the culture medium may be considered factors for inducing higher alkaloid production by C. peruvianus callous tissues.

Maria de Fátima Pires da Silva Machado

Papers

Produção de metabólitos secundários em cultura de células e tecidos de plantas: o exemplo dos gêneros Tabernaemontana e Aspidosperma

In vitro propagation ofCereus peruvianus mill. (cactaceae)

Genetic variability of Prochilodus lineatus (Characiformes, Prochilodontidae) in the upper Paraná river

Micropropagation of Cereus peruvianus mill. (cactaceae) by areole activation

Alkaloid production by callous tissue cultures of Cereus peruvianus (Cactaceae).