Navegando por Palavras-chave "18S rDNA"

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    Descrição morfológica e molecular de parasitos do filo Myxozoa em peixes Prochilodus costatus e Prochilodus argenteus do Rio São Francisco/MG e Prochilodus lineatus do rio Mogi Guaçu/SP
    (Universidade Federal de São Paulo, 2013-11-07) Zatti, Suellen Aparecida [UNIFESP]; Adriano, Edson Aparecido [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    O filo Myxozoa compreende organismos metazoários, endoparasitos e altamente especializados, tanto em relação aos hospedeiros quanto em relação ao tecido que infectam. No mundo são conhecidas aproximadamente 2.300 espécies e na América do Sul foram descritas até aqui pouco mais de 80 espécies. O avanço nos estudos desses parasitos no Brasil é muito recente, sendo que algumas espécies consideradas patogênicas tem sido descritas. Os estudos taxonômicos clássicos desses organismos tem abordado apenas os caracteres morfológicos. Contudo, atualmente, o sequenciamento do gene 18S rDNA tem sido empregado com sucesso na descriminação de novas espécies. Esse trabalho teve por objetivo estudar mixosporídeos parasitos de peixes da família Prochilodontidae nas bacias dos rios São Francisco, MG e Mogi Guaçu, SP. Foram analisados exemplares de Prochilodus costatus Valenciennes, 1850 e Prochilodus argenteus Agassiz, 1829 do rio São Francisco e Prochilodus lineatus Valenciennes, 1829 do rio Mogi Guaçu. Análises morfológicas (microscopia de luz, análise ultraestrutural) e das sequências do gene 18S rDNA, com subsequentes inferências filogenéticas, foram os procedimentos utilizados. Esta dissertação foi organizada na forma de capítulos, sendo que no primeiro é apresentado o estudo de uma espécie do gênero Myxobolus Lom & Dykova, 1992 encontrada infectando brânquias de P. costatus, a qual foi considerada como uma espécie ainda não descrita. Os dados morfológicos, ultraestruturais e moleculares desta espécie são aqui apresentados. O segundo capítulo trata de um estudo que tem como base o sequenciamento do gene 18S rDNA de duas espécies de Myxobolus já conhecidas e que infectam peixes do gênero Prochilodus: Myxobolus porofilus Adriano et al. 2002 parasito de P. lineatus e Myxobolus franciscoi Eiras et al. 2010 encontrada infectando P. costatus. As análises moleculares mostram que M. porofilus e M. cf. franciscoi, mesmo apresentando características morfológicas muito semelhantes e infectando hospedeiros filogeneticamente muito próximos (mesmo gênero), são duas espécies geneticamente distintas. As análises filogenéticas aqui realizadas mostram o agrupamento parafilético entre as espécies dos gêneros Myxobolus e Henneguya Thélohan, 1892 e que as espécies de mixosporídeos se agruparam principalmente de acordo com as famílias dos peixes hospedeiros.
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    Henneguya cuniculator sp nov., a parasite of spotted sorubim Pseudoplatystoma corruscans in the Sao Francisco Basin, Brazil
    (Inter-research, 2014-01-16) Naldoni, Juliana; Maia, Antonio Augusto Mendes; Silva, Marcia Ramos Monteiro da; Adriano, Edson Aparecido [UNIFESP]; Universidade Estadual de Campinas (UNICAMP); Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Henneguya cuniculator sp. nov. was found infecting spotted sorubim catfish Pseudoplatystoma corruscans from the Sao Francisco River, Minas Gerais, Brazil. the parasites form elongated plasmodia of up to 1 cm in length in the gill filaments. Mature spores were ellipsoidal from the frontal view, with total length of 29.4 +/- 2.4 (mean +/- SD, range 23.3-32.4) mu m, body length of 12.1 +/- 1.0 (10.0-14.7) mu m, width of 4.8 +/- 0.4 (4.0-5.9) mu m, and tail length of 16.7 +/- 2.0 (12.3-19.4) mu m. From the lateral view, spores were biconvex, with thickness of 4.2 +/- 0.7 (3.9-4.9) mu m. the polar capsules were elongated and equal in size, 6.2 +/- 0.3 (5.2-6.2) mu m in length, and 1.8 +/- 0.1 (1.4-1.9) mu m in width. Ultrastructural analysis showed that the plasmodial wall had delicate projections towards the host tissue and a thin layer that prevented contact between the host cells and the parasite. in the ectoplasm, few mitochondria were observed, while generative cells, early stages of sporogenesis, and advanced spore development occurred in the plasmodial periphery, and more mature spores in internal regions. Histopathological analysis showed that plasmodia developed in the sub-epithelial connective tissue of gill filaments, causing compression of the adjacent tissues, deformation of gill filaments, and lamellar fusion. Phylogenetic analysis, based on 18S rDNA genes and using only Henneguya/Myxobolus species parasites of siluriform fish, showed grouping according to the fish family.
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    The morphological and molecular characterization of Henneguya rotunda n. sp., a parasite of the gill arch and fins of Salminus brasiliensis from the Mogi Guacu River, Brazil
    (Springer, 2014-05-01) Moreira, Gabriel Sassarão Alves; Adriano, Edson Aparecido [UNIFESP]; Silva, Marcia Ramos Monteiro da; Ceccarelli, Paulo Sergio; Maia, Antonio Augusto Mendes; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Campinas (UNICAMP); Inst Chico Mendes Conservacao Biodiversidade ICMb
    A new species of myxosporea (Henneguya rotunda n. sp.) was found in the membrane of the gill arch and the fins of Salminus brasiliensis in the Mogi Gua double dagger u River, municipality of Pirassununga, So Paulo state, Brazil. Morphological and morphometric analyses using light microscopy revealed parasites with similar characteristics at both infection sites. the mature spores found infecting the fins had oval spore body with 7.1 +/- 0.2 mu m in length, 5.6 +/- 0.2 mu m in width, 3.7 +/- 0.1 mu m in thickness, 16.4 +/- 1.2 mu m in length of the caudal process, and 23.6 +/- 1.1 mu m in total length of the spore. in a frontal view, the polar capsule was observed to be symmetrical with 3.4 +/- 0.2 mu m in length and 1.8 +/- 0.1 mu m in width. Mature spores contain six to seven turns of the polar filaments. the morphometric data concerning the spores obtained from plasmodia from the membrane of the gill arch were similar to those from the fins. Ultrastructure analysis revealed that the plasmodial wall was formed by a single membrane and had numerous pinocytotic canals connecting the outside of the plasmodia to the ectoplasm zone. Beyond that, various electron-translucent vesicles also were observed at the periphery of the plasmodium. the molecular analyses of the 18S rDNA gene from the spores obtained from the gill arch membrane and fin membrane showed that these sequences shared 100 % similarity. Phylogenetic studies using maximum parsimony and maximum likelihood methods demonstrated the polyphyletic clustering of the myxosporean parasites of characiform fishes. H. rotunda n. sp. clustered as a sister species of Myxobolus pantanalis, also a parasite of S. brasiliensis.
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    Phylogenetic and host-parasite relationship analysis of Henneguya multiplasmodialis n. sp infecting Pseudoplatystoma spp. in Brazilian Pantanal wetland
    (Elsevier B.V., 2012-04-30) Adriano, Edson Aparecido [UNIFESP]; Carriero, Mateus Maldonado; Maia, Antonio Augusto Maia; Silva, Marcia Ramos Monteiro da; Naldoni, Juliana; Ceccarelli, Paulo Sergio; Arana, Sarah; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP); Universidade Estadual de Campinas (UNICAMP); Inst Chico Mendes Conservacao Biodiversidade ICMb
    A new species of the genus Henneguya (Henneguya multiplasmodialis n. sp.) was found infecting the gills of three of 89 specimens (3.3%) of Pseudoplatystoma corruscans and two of 79 specimens (2.6%) of Pseudoplatystoma reticulatum from rivers in the Pantanal wetland, Brazil. Partial sequencing of the 18S rDNA gene of the spores obtained from one plasmodium from the gills of P. corruscans and other one from the gills of P. reticulatum, respectively, resulted in a total of 1560 and 1147 base pairs. As the spores of H. multiplasmodialis n. sp. resemble those of Henneguya corruscans, which is also a parasite of P. corruscans, sequencing of the 18S rDNA gene of the spores of H. corruscans found on P. corruscans caught in the Brazilian Pantanal wetland was also provided to avoid any taxonomic pendency between these two species, resulting in 1913 base pairs. the sequences of H. multiplasmodialis n. sp. parasite of P. corruscans and P. reticulatum and H. corruscans did not match any of the Myxozoa available in the GenBank. the similarity of H. multiplasmodialis n. sp. obtained from P. corruscans to that from P. reticulatum was of 99.7%. Phylogeny revealed a strong tendency among Henneguya species to form clades based on the order and/or family of the host fish. H. multiplasmodialis n. sp. clustered in a clade with Henneguya eirasi and H. corruscans, which are also parasites of siluriforms of the family Pimelodidae and, together with the clade composed of Henneguya spp. parasites of siluriforms of the family Ictaluridae, formed a monophyletic clade of parasites of siluriform hosts. the histological study revealed that the wall of the plasmodia of H. multiplasmodialis n. sp. were covered with a stratified epithelium rich in club cells and supported by a layer of connective tissue. the interior of the plasmodia had a network of septa that divided the plasmodia into numerous compartments. the septa were composed of connective tissue also covered on both sides with a stratified epithelium rich in club cells. Inflammatory infiltrate was found in the tissue surrounding the plasmodia as well as in the septa. (C) 2011 Elsevier B.V. All rights reserved.