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Identification of Schistosoma mansoni microRNAs
Mariana C Sim?es, Jonathan Lee, Appolinaire Djikeng, Gustavo C Cerqueira, Adhemar Zerlotini, Rosiane A da Silva-Pereira, Andrew R Dalby, Philip LoVerde, Najib M El-Sayed, Guilherme Oliveira
BMC Genomics , 2011, DOI: 10.1186/1471-2164-12-47
Abstract: Homology search using the high-throughput pipeline was performed with all known miRNAs in miRBase. A total of 6,211 mature miRNAs were used as reference sequences and 110 unique S. mansoni sequences were returned by BLASTn analysis. The existing mature miRNAs that produced these hits are reported, as well as the locations of the homologous sequences in the S. mansoni genome. All BLAST hits aligned with at least 95% of the miRNA sequence, resulting in alignment lengths of 19-24 nt. Following several filtering steps, 15 potential miRNA candidates were identified using this approach. By sequencing small RNA cDNA libraries from adult worm pairs, we identified 211 novel miRNA candidates in the S. mansoni genome. Northern blot analysis was used to detect the expression of the 30 most frequent sequenced miRNAs and to compare the expression level of these miRNAs between the lung stage schistosomula and adult worm stages. Expression of 11 novel miRNAs was confirmed by northern blot analysis and some presented a stage-regulated expression pattern. Three miRNAs previously identified from S. japonicum were also present in S. mansoni.Evidence for the presence of miRNAs in S. mansoni is presented. The number of miRNAs detected by homology-based computational methods in S. mansoni is limited due to the lack of close relatives in the miRNA repository. In spite of this, the computational approach described here can likely be applied to the identification of pre-miRNA hairpins in other organisms. Construction and analysis of a small RNA library led to the experimental identification of 14 novel miRNAs from S. mansoni through a combination of molecular cloning, DNA sequencing and expression studies. Our results significantly expand the set of known miRNAs in multicellular parasites and provide a basis for understanding the structural and functional evolution of miRNAs in these metazoan parasites.Small non-coding RNAs are increasingly providing insights into important aspects of the bi
Protein tyrosine kinases in Schistosoma mansoni
Bahia, Diana;Andrade, Luiza Freire;Ludolf, Fernanda;Mortara, Renato Arruda;Oliveira, Guilherme;
Memórias do Instituto Oswaldo Cruz , 2006, DOI: 10.1590/S0074-02762006000900022
Abstract: the identification and description of signal transduction molecules and mechanisms are essential to elucidate schistosoma mansoni host-parasite interactions and parasite biology. this mini review focuses on recent advancements in the study of signalling molecules and transduction mechanisms in s. mansoni, drawing special attention to the recently identified and characterised protein tyrosine kinases of s. mansoni.
Nuevas especies de Malvaceae
Antonio Krapovickas
Bonplandia , 2008,
Abstract: Se describen seis especies nuevas de Malvaceae: Abutilon heterochros, Gaya ibitipocana, Sida itaparicana, Sida Arboae y Sida Meloana de Brasil e Hibiscus manuripiensis de Bolivia
Experimental models of Schistosoma mansoni infection
Cheever, Allen W;Lenzi, Jane A;Lenzi, Henrique L;Andrade, Zilton A;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000700002
Abstract: experimental models of schistosoma mansoni infections in mammals have contributed greatly to our understanding of the pathology and pathogenesis of infection. we consider here hepatic and extrahepatic disease in models of acute and chronic infection. experimental schistosome infections have also contributed more broadly to our understanding of granulomatous inflammation and our understanding of th1 versus th2 related inflammation and particularly to th2-mediated fibrosis of the liver.
Experimental models of Schistosoma mansoni infection  [cached]
Cheever Allen W,Lenzi Jane A,Lenzi Henrique L,Andrade Zilton A
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: Experimental models of Schistosoma mansoni infections in mammals have contributed greatly to our understanding of the pathology and pathogenesis of infection. We consider here hepatic and extrahepatic disease in models of acute and chronic infection. Experimental schistosome infections have also contributed more broadly to our understanding of granulomatous inflammation and our understanding of Th1 versus Th2 related inflammation and particularly to Th2-mediated fibrosis of the liver.
NUEVAS ESPECIES DE MALVACEAE New species of Malvaceae
Antonio Krapovickas
Bonplandia , 2010,
Abstract: Se describen seis especies nuevas de Malvaceae: Abutilon heterochros, Gaya ibitipocana, Sida itaparicana, Sida Arboae y Sida Meloana de Brasil e Hibiscus manuripiensis de Bolivia Six new species of Malvaceae are described: Abutilon heterochros, Gaya ibitipocana, Sida itaparicana, Sida Arboae and Sida Meloana from Brasil and Hibiscus manuripiensis from Bolivia
Control of calcium homeostasis in Schistosoma mansoni
No?l, F;Cunha, VMN;Silva, CLM;Mendon?a-Silva, DL;
Memórias do Instituto Oswaldo Cruz , 2001, DOI: 10.1590/S0074-02762001000900012
Abstract: calcium signalling is fundamental for muscular contractility of schistosoma mansoni. we have previously described the presence of transport atpases (na+,k+-atpase and (ca2+-mg2+)-atpase) and calcium channels (ryanodine receptors - ryr) involved in control of calcium homeostasis in this worm. here we briefly review the main technics (atpase activity, binding with specific radioligands, fluxes of 45ca2+ and whole worm contractions) and results obtained in order to compare the distribution patterns of these proteins: thapsigargin-sensitive (ca2+-mg2+)-atpase activity and ryr co-purified in p1 and p4 fractions mainly, which is compatible with a sarcoplasmic reticulum localization, while basal atpase (along with na+,k+-atpase) and thapsigargin-resistant (ca2+-mg2+)-atpase have a distinct distribution, indicative of their plasma membrane localization. finally we attempt to integrate these contributions with data from other groups in order to propose the first synoptic model for control of calcium homeostasis in s. mansoni.
Control of calcium homeostasis in Schistosoma mansoni  [cached]
No?l F,Cunha VMN,Silva CLM,Mendon?a-Silva DL
Memórias do Instituto Oswaldo Cruz , 2001,
Abstract: Calcium signalling is fundamental for muscular contractility of Schistosoma mansoni. We have previously described the presence of transport ATPases (Na+,K+-ATPase and (Ca2+-Mg2+)-ATPase) and calcium channels (ryanodine receptors - RyR) involved in control of calcium homeostasis in this worm. Here we briefly review the main technics (ATPase activity, binding with specific radioligands, fluxes of 45Ca2+ and whole worm contractions) and results obtained in order to compare the distribution patterns of these proteins: thapsigargin-sensitive (Ca2+-Mg2+)-ATPase activity and RyR co-purified in P1 and P4 fractions mainly, which is compatible with a sarcoplasmic reticulum localization, while basal ATPase (along with Na+,K+-ATPase) and thapsigargin-resistant (Ca2+-Mg2+)-ATPase have a distinct distribution, indicative of their plasma membrane localization. Finally we attempt to integrate these contributions with data from other groups in order to propose the first synoptic model for control of calcium homeostasis in S. mansoni.
Characterization of the Phytochelatin Synthase of Schistosoma mansoni  [PDF]
Debalina Ray,David L. Williams
PLOS Neglected Tropical Diseases , 2011, DOI: 10.1371/journal.pntd.0001168
Abstract: Treatment for schistosomiasis, which is responsible for more than 280,000 deaths annually, depends exclusively on the use of praziquantel. Millions of people are treated annually with praziquantel and drug resistant parasites are likely to evolve. In order to identify novel drug targets the Schistosoma mansoni sequence databases were queried for proteins involved in glutathione metabolism. One potential target identified was phytochelatin synthase (PCS). Phytochelatins are oligopeptides synthesized enzymatically from glutathione by PCS that sequester toxic heavy metals in many organisms. However, humans do not have a PCS gene and do not synthesize phytochelatins. In this study we have characterized the PCS of S. mansoni (SmPCS). The conserved catalytic triad of cysteine-histidine-aspartate found in PCS proteins and cysteine proteases is also found in SmPCS, as are several cysteine residues thought to be involved in heavy metal binding and enzyme activation. The SmPCS open reading frame is considerably extended at both the N- and C-termini compared to PCS from other organisms. Multiple PCS transcripts are produced from the single encoded gene by alternative splicing, resulting in both mitochondrial and cytoplasmic protein variants. Expression of SmPCS in yeast increased cadmium tolerance from less than 50 μM to more than 1,000 μM. We confirmed the function of SmPCS by identifying PCs in yeast cell extracts using HPLC-mass spectrometry. SmPCS was found to be expressed in all mammalian stages of worm development investigated. Increases in SmPCS expression were seen in ex vivo worms cultured in the presence of iron, copper, cadmium, or zinc. Collectively, these results indicate that SmPCS plays an important role in schistosome response to heavy metals and that PCS is a potential drug target for schistosomiasis treatment. This is the first characterization of a PCS from a parasitic organism.
Intermediate hosts of schistosoma mansoni in Brazil
Carvalho, Omar dos Santos;
Memórias do Instituto Oswaldo Cruz , 1992, DOI: 10.1590/S0074-02761992000800048
Abstract: the brazilian planorbidical chart is slowly but progressively been increased by new data. distribution of vector species of schistosoma mansoni, according to paraense, 1986, may be thus resumed: biomphalaria glabrata - delimited by paralells 13 and 21-s and meridians 39 and 45-w, area of greater dominance (southerst bahia, oriental half of minas gerais and espírito santo). it is observed along the coast line of the state of sergipe, alagoas, pernambuco, paraíba and rio grande do norte. starting from there, it is found towards the southwest, in the direction to the sao francisco river and south-center of minas gerais. isolated population may be observed in other states. its presence is probably, associated to the transmission of schistosomiasis in all areas where it occurs. b. tenagophila - extends it self through a wide strip of coast-line the south of bahia (17-45"s, 39-15'w), rs(33-41's, 53-27'w). in sao paulo and rio grande do sul states it is found further inland. it is important in schistosomiasis transmission in the paraíba valley (sp). isolated populations are observed in the federal district and minas gerais state. b. straminea - better adapter species to climatic variation, having a more dense ditribution in the northeast (41-wand 110-s), south of bahia and northeast of minas gerais (150 and 180-s, 400 and 440-w) it is less susceptible than b. glabrata, being however the most important responsible for the transmission of s. mansoni in the northeast, chiefly in the northeastern dry area, where it is almost the only transmissive species.
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