Genome Sequence Of Streptomyces Wadayamensis Strain A23, An Endophytic Actinobacterium From Citrus Reticulata.

The actinobacterium Streptomyces wadayamensis A23 is an endophyte of Citrus reticulata that produces the antimycin and mannopeptimycin antibiotics, among others. The strain has the capability to inhibit Xylella fastidiosa growth. The draft genome of S. wadayamensis A23 has ~7.0 Mb and 6,006 protein-coding sequences, with a 73.5% G+C content.

Ophionereis reticulata (Echinodermata, Ophiuroidea)

This study compared the arm regeneration frequencies in two different populations of Ophionereis reticulata (Say, 1825) in São Sebastião, Southeast Brazil and observed arm regeneration between age classes (juvenile and adults) and sexes (male and female). From the 1,170 individuals sampled, 1,089 (92.2%) showed signs of arm regeneration. The relative frequencies of regenerating arms in the two areas were not different (Baleeiro Isthmus: 91.3% and Grande Beach: 99.5%). Both areas also presented similar values for the number of arms regenerating/individual and in the frequency of regenerating individuals. The major part of the regenerating scars was concentrated in the distal portion of the arm. Sub-lethal predation is most likely the cause to the high rates of arm regeneration in O. reticulata. There was no significant differences in the regeneration rates between females (3.57 ± 1.36 arms regenerating/individual) and males (3.47 ± 1.42).

Projections from the substantia nigra pars reticulata to the motor thalamus of the rat: Single axon reconstructions and immunohistochemical study

This is a study in the rat of the distribution of specific neurotransmitters in neurones projecting from the substantia nigra reticulata (SNR) to the ventrolateral (VL) and ventromedial (VM) thalamic nuclei. Individual axons projecting from the SNR to these thalamic nuclei have also been reconstructed following small injection of the anterograde tracer dextran biotin into the the SNR. Analysis of reconstructions revealed two populations of SNR neurones projecting onto the VL and VM thalamic nuclei. One group projects directly onto the VM and VL, and the other projects to the VM/VL and to the parafascicular nucleus. In another set of experiments Fluoro-Gold was injected into the VL/VM to label SNR projection neurones retrogradely, and immunohistochemistry was performed to determine the distribution of choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), gamma -aminobutyric acid (GABA), and glutamate in Fluoro-Gold-labelled SNR projection neurones. Most SNR-VL/VM thalamic projection neurones were immunoreactive to acetylcholine or glutamate, whereas only 25% of the projection neurones were found to be immunoreactive to GABA. (C) 2001 Wiley-Liss, Inc.

Diterpenos de Copaifera reticulata Ducke com atividade larvicida contra Aedes aegypti (L.) (Diptera, Culicidae)

The objective of this study was to evaluate the larvicidal activity of diterpenoids obtained from the oil-resin of Copaifera reticulata against Aedes aegypti larvae, the principal vector of dengue and urban yellow fever. Four diterpenes were obtained from oil-resin extraction with organic solvents and subsequent chromatographic and spectroscopic procedures allowed to isolation and identification of these compounds as 3-b-acetoxylabdan-8(17)-13-dien-15-oic acid (1), alepterolic acid (2), 3-b-hidroxylabdan-8(17)-en-15-oic acid (3), and ent-agatic acid (4). Each compound was previously dissolved in dimethylsulphoxide, and distilled water was added to obtain the desired concentrations. Twenty larvae of third instars were placed into plastic beckers, containing the solution test (25 mL), in a five repetitions scheme, and their mortality, indicated by torpor and darkening of the cephalic capsule, was recorded after 48h. Probit analyses were used to determine lethal concentrations (LC50 and LC90) and their respective 95% confidence intervals. This study showed that only diterpenoids 1 and 2 exhibited larvicidal properties with LC50 of 0.8 ppm and 87.3 ppm, respectively, revealing the former as the most toxic compound against third instars of Ae. aegypti. Therefore, this compound seems to be an interesting source for new metabolite to be exploited.

Larvicidal activity of oil-resin fractions from the Brazilian medicinal plant Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) against Aedes aegypti (Diptera, Culicidae)

Oil-resin fractions from Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) were evaluated for larvicidal activity on third larval instars of Aedes aegypti, in searching for alternative control methods for this mosquito. The bioactive fractions were chemically monitored by thin-layer chromatography, ¹H and 13C nuclear magnetic resonance and mass spectrometry. Bioassays were performed using five repetitions, at a temperature of 28 ± 1°C, relative humidity of 80 ± 5% and light and dark cycles of 12h. Mortality was indicated by darkening of the cephalic capsule after 24h of exposure of the larvae to the solutions. The most active fractions were CRM1-4 (sesquiterpenes) and CRM5-7 (labdane diterpenes), which showed LC50 values of 0.2 and 0.8ppm, respectively.

Alterações ultraestruturais em larvas de Aedes aegypti submetidas ao diterpeno labdano, isolado de Copaifera reticulata (Leguminosae), e à uma fração rica em taninos de Magonia pubescens (Sapindaceae)

INTRODUÇÃO: Dengue é um importante problema de saúde pública, em vários países, e tem como principal vetor o Aedes aegypti, mosquito mais adaptado às áreas urbanizadas. Apresenta-se, pela primeira vez, as alterações ultraestruturais em larvas de 3º estádio, desse mosquito, causadas pelos larvicidas naturais, um diterpeno labdano, extraído de Copaifera reticulata, e uma fração rica em taninos catéquicos, extraída de Magonia pubescens, evidenciando o mecanismo de ação dessas substâncias. MÉTODOS: Os experimentos foram realizados com larvas de 3º estádio em solução de 0,9ppm, do diterpeno (3-β-acetoxylabdan-8(17)-13-dien-15-óico) e de 3,7ppm, da fração majoritária de tanino catéquico de massa molecular 864Da. Obtiveram-se as substâncias através de fracionamentos cromatográficos sucessivos, identificadas por ressonância magnética nuclear de hidrogênio e espectrometria de massas. As larvas que atingiram estado letárgico foram coletadas e dissecadas e seus tubos digestórios fixados, desidratados, emblocados e polimerizados. Cortes ultrafinos foram feitos e contrastados com acetato de uranila 3% e citrato de chumbo, posteriormente, levados ao microscópio eletrônico. RESULTADOS: As principais alterações ultraestruturais provocadas pelos diterpeno e tanino sobre larvas de Aedes aegypti foram vacuolização citoplasmática, desorganização e degeneração celular, mudança estrutural dos microvilos e deslocamento das células da lâmina basal. CONCLUSÕES: O diterpeno e a fração rica em taninos catéquicos provocaram a morte das larvas de Aedes aegypti através da destruição celular no intestino médio.

FOOD CONCENTRATION AND TEMPERATURE EFFECTS ON LIFE CYCLE CHARACTERISTICS OF TROPICAL CLADOCERA (Daphnia gessneri Herbst, Diaphanosoma sarsi Richard, Moina reticulata (Daday)): I. DEVELOPMENT TIME

The effects of food concentration and temperature on embryonic and postem-bryonic duration of three tropical species, Daphnia gessneri(1.5mm), Diaphanosoma sarsi(1.2mm) and Moina reticulata(0.8mm), were investigated as part of life cycle studies which included growth, body size and reproduction. These are the very first experimental studies undertaken on these species. The long-term growth experiments were performed under controlled laboratory conditions at all combinations of temperature (22"C, 27"C and 32"C) and constant food concentration (0.03, 0.05, 0.10, 0.25, 0.50 and 1.00 mgC/L) of the unicellular green alga Scenedesmus acutus.Animals were examined twice daily throughout their life cycle from the neonate to third adult instar. In all three species, temperature exerted the most powerful influence on embryonic duration but there was also a smaller food effect. In D. gessneri,postembry-onic durations remained more or less the same at food levels 0.25 mgC/L but were influenced by temperature. At food concentrations of 0.1 mgC/L or lower, postembryonic durations became increasingly prolonged, particularly at high temperatures. This threshold concentration is affected by temperature: in D. gessneri,it was 0.1 mgC/L at 22oC and 27oC but higher at 32oC (between 0.25 and 0.50 mgC/L). At the same temperature of 27oC, the food threshold level varied between species: it was higher (0.25 mgC/L) for D. sarsiand lower (0.05 mgC/L) for M. reticulatacompared with D. gessneri(0.1 mgC/L). In both embryonic and postembryonic durations there is a body size effect as the absolute durations were longest in the largest species and shortest in the smallest species In all three species, prolongation of postembryonic duration at combinations of high temperature and lowered food levels was accompanied by increased number of juvenile instars.

Ophionereis reticulata (Echinodermata, Ophiuroidea)

This study compared the arm regeneration frequencies in two different populations of Ophionereis reticulata (Say, 1825) in São Sebastião, Southeast Brazil and observed arm regeneration between age classes (juvenile and adults) and sexes (male and female). From the 1,170 individuals sampled, 1,089 (92.2%) showed signs of arm regeneration. The relative frequencies of regenerating arms in the two areas were not different (Baleeiro Isthmus: 91.3% and Grande Beach: 99.5%). Both areas also presented similar values for the number of arms regenerating/individual and in the frequency of regenerating individuals. The major part of the regenerating scars was concentrated in the distal portion of the arm. Sub-lethal predation is most likely the cause to the high rates of arm regeneration in O. reticulata. There was no significant differences in the regeneration rates between females (3.57 ± 1.36 arms regenerating/individual) and males (3.47 ± 1.42).

Monophyletic origin of multiple clonal lineages in an asexual fish (Poecilia formosa).

Despite the advantage of avoiding the costs of sexual reproduction, asexual vertebrates are very rare and often considered evolutionarily disadvantaged when compared to sexual species. Asexual species, however, may have advantages when colonizing (new) habitats or competing with sexual counterparts. They are also evolutionary older than expected, leaving the question whether asexual vertebrates are not only rare because of their 'inferior' mode of reproduction but also because of other reasons. A paradigmatic model system is the unisexual Amazon molly, Poecilia formosa, that arose by hybridization of the Atlantic molly, Poecilia mexicana, as the maternal ancestor, and the sailfin molly, Poecilia latipinna, as the paternal ancestor. Our extensive crossing experiments failed to resynthesize asexually reproducing (gynogenetic) hybrids confirming results of previous studies. However, by producing diploid eggs, female F(1) -hybrids showed apparent preadaptation to gynogenesis. In a range-wide analysis of mitochondrial sequences, we examined the origin of P. formosa. Our analyses point to very few or even a single origin(s) of its lineage, which is estimated to be approximately 120,000 years old. A monophyletic origin was supported from nuclear microsatellite data. Furthermore, a considerable degree of genetic variation, apparent by high levels of clonal microsatellite diversity, was found. Our molecular phylogenetic evidence and the failure to resynthesize the gynogenetic P. formosa together with the old age of the species indicate that some unisexual vertebrates might be rare not because they suffer the long-term consequences of clonal reproduction but because they are only very rarely formed as a result of complex genetic preconditions necessary to produce viable and fertile clonal genomes and phenotypes ('rare formation hypothesis').

Efficacy of Citrus reticulata and Mirazid in treatment of Schistosoma mansoni

This work has been carried out to investigate the effect of Schistosoma mansoni infection on mice livers after treatment with the ethanolic extract of Citrus reticulata root or the oleo-resin extract from Myrrh of Commiphora molmol tree (Mirazid), as a new antishistosomal drug. Marker enzymes for different cell organelles were measured; succinate dehydrogenase (SDH); lactate dehydrogenase (LDH) and its isoenzymes; glucose-6-phosphatase (G-6-Pase); acid phosphatase (AP) and 5'- nucleotidase. Liver function enzymes; aspartate aminotransferase (AST); alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were also estimated. Parasitological studies through ova count and worm burden will also be taken into consideration. The results showed a marked reduction in SDH, LDH, AST, and ALT enzyme activities and a significant increase in G-6-Pase, AP, 5'- nucleotidase, and ALP after S. mansoni infection. A noticeable alteration in LDH subunits were also noticed. Treatment with C. reticulata or Mirazid improved all the previous enzyme activities with a noticeable reduction in ova count and worm burden.

The life history of Pygidiopsis macrostomum Travassos, 1928 (Digenea: Heterophyidae)

The life history of the trematode Pygidiopsis macrostomum Travassos, 1928 is described for the first time. Rediae and cercariae were obtained from naturally infected snails Heleobia australis (d´Orbigny), a new first intermediate host. Metacercariae were found encysted in the mesenteries of three naturally infected guppies, Phalloptychus januarius (Hensel), Jenynsia multidentata (Jenyns) (new host records) and Poecilia vivipara Bloch and Schneider. Experimental infections were successfully completed in the intermediate hosts H. australis and Poe. vivipara reared in the laboratory and hamsters Mesocricetus auratus Waterhouse were utilised as a definitive host.

Morphology, testes development and behaviour of unusual triploid males in microchromosome-carrying clones of Poecilia formosa.

In a microchromosome-carrying laboratory stock of the normally all-female Amazon molly Poecilia formosa triploid individuals were obtained, all of which spontaneously developed into males. A comparison of morphology of the external and internal insemination apparatus and the gonads, sperm ploidy and behaviour, to laboratory-bred F(1) hybrids revealed that the triploid P. formosa males, though producing mostly aneuploid sperm, are partly functional males that differ mainly in sperm maturation and sexual motivation from gonochoristic P. formosa males.

CARACTERÍSTICAS DO FRUTO DA VARIEDADE SPAN AMERICANA (Citrus reticulata Blanco): UMA TANGERINA DO TIPO 'PONCÃ' DE MATURAÇÃO PRECOCE

A tangerina-'Poncã' é bastante apreciada pelo consumidor brasileiro. No Estado de São Paulo, a maturação de seus frutos ocorre nos meses de abril a agosto. Com o mercado ávido por frutas de mesa e agravado pelo problema da ocorrência da clorose variegada dos citros (CVC), que afeta principalmente as variedades de laranjas-doces, tem havido um aumento considerável no plantio dessa variedade. Dessa forma, um excesso de produção, num mesmo período, faz com que os preços caiam, desestimulando assim os produtores. O Centro de Citricultura Sylvio Moreira (CCSM) vem buscando outras alternativas no sentido de obter, durante o ano todo, esse tipo de tangerina. Assim sendo, foram realizados estudos de caracterização de frutos, em diversas épocas do ano, com o acompanhamento dos níveis de maturação, envolvendo acessos do Banco de Germoplasma do CCSM. Dentre as variedades estudadas, quanto à precocidade e qualidade dos frutos, destacou-se a Span Americana. A tangerina-'Poncã' tem seu período de maturação para as condições edafoclimáticas do CCSM, nos meses de maio e junho. Já a variedade Span Americana, que apresenta frutos similares à 'Poncã' tradicional, tem maturação bastante precoce, podendo ser iniciada a sua colheita no mês de março.

Indução do florescimento e crescimento de tangerineira 'Poncã' (Citrus reticulata Blanco) em função da irrigação e da aplicação de paclobutrazol

O experimento foi conduzido na Faculdade de Ciências Agronômicas - UNESP/Câmpus de Botucatu (SP), com o objetivo de avaliar o florescimento fora de época e o crescimento vegetativo da tangerineira 'Poncã'. Nesse contexto, adotou-se o delineamento estatístico em blocos casualizados, em parcelas subdivididas, com duas repetições, na instalação do ensaio. Os dois tratamentos de -0,03 e -0,05 MPa, como potenciais mínimos da água no solo, constituíram as parcelas e as quatro doses de paclobutrazol: 0; 4; 8 e 12 g por planta, nas subparcelas. No segundo ano de pesquisa, foram mantidas as mesmas parcelas e foram aplicadas nas plantas das subparcelas as doses de 0; 500; 1000 e 2000 mg l-1 de paclobutrazol, via foliar. Cada parcela foi constituída de 16 plantas, sendo oito destinadas à avaliação. Utilizou-se, em ambas as combinações, de um tratamento sem irrigação (-0,07 MPa) e sem aplicação de paclobutrazol, como testemunha. Foram avaliados parâmetros, como a altura, diâmetro médio, volume e área de projeção da copa e condutância estomática para caracterizar a resposta das plantas aos tratamentos empregados. Concluiu-se que a aplicação do paclobutrazol e a variação do potencial da água no solo não proporcionaram a indução do florescimento fora de época das tangerineiras, e que os níveis de paclobutrazol influenciaram no desenvolvimento das plantas.

Comportamento fisiológico de sementes de tangerina (Citrus reticulata Blanco) submetidas à desidratação

O objetivo desta pesquisa foi o de estudar os efeitos imediatos da desidratação sobre o comportamento fisiológico das sementes de tangerina (Citrus reticulata Blanco var. Cleópatra). Assim, sementes extraídas manualmente de frutos maduros foram lavadas em água corrente e drenadas à sombra. Em seguida, uma porção representativa de sementes foi removida a fim de constituir o tratamento com o maior grau de umidade (49%) a ser estudado. As sementes remanescentes foram submetidas à desidratação em equipamento com circulação forçada de ar (28±2°C), visando à obtenção dos tratamentos (39; 32; 24; 13; 10 e 7% H2O) referentes aos demais graus de umidade desejados. Foram realizadas avaliações do grau de umidade, da germinação, da taxa e da velocidade de emergência das plântulas, dos comprimentos da raiz, do hipocótilo e da plântula. Concluiu-se que o potencial fisiológico das sementes, considerando o intervalo de 49 a 7% para o grau de umidade, é favorecido pela desidratação até 39% H2O.