Processos carioevolutivos na ordem tetraodontiformes: uma visão através de suas diferentes linhagens

Given the great diversity of fishes, the Order Tetraodontiformes stands to show genetic and morphological characteristics enough singular. The fishes of this order have a compact DNA which favors molecular studies, as well as comparisons with more basal species. Model of genome evolution, there are still many gaps in knowledge about their chromosomal patterns and how evolutionary rearrangements influence the marked variation in DNA content of this order. In view of this, we present cytogenetic analyzes of the species Acanthostracion quadricornis (Ostraciidae), A. polygonius (Ostraciidae) Melichthys niger (Balistidae) Cantherhines macrocerus (Monacanthidae) and C. pullus (Monacanthidae), Lagocephalus laevigatus, Colomesus psittacus and Canthigaster figueiredoi (Tetraodontidae), to contribute with cytogenetic data for this group. The analysis was performed by C-banding, Ag-RONs, coloring with base-specific fluorochromes DAPI-CMA3, restriction enzymes AluI, EcoRI, TaqI, PstI and HinfI and in situ hybridization with probes for ribosomal DNA 18S and 5S. The heterochromatic ultrastructure of A. quadricornis and A. polygonius revealed a outstanding heterochromatin content, which may indicate that the accumulation or loss of extensive heterochromatin content could be responsible for large variations in genomic content displayed in different Tetraodontiformes families. The species Cantherhines macrocerus, C. pullus (Monacanthidae) and Melichthys niger (Balistidae) shows a huge karyotypic similarity both numerically and structural. L. laevigatus showed similar cytogenetic features (2n = 44 and single RONs) to the species of the genus Takifugu, which reinforces the idea of their phylogenetic relationships. C. psittacus presented the highest diploid number described for the family (2n = 56) and large amount of HC, features that related with its sister family Diodontidae. Cytogenetic analysis in C. figueiredoi revealed heterochromatic polymorphisms, RONs multiple and Bs chromosomes. These events are rare in marine fishes, and are possibly associated with the strong restructuring and genomic reduction that this family has been suffered. These features, plus the morphological and molecular data suggests that these species share the same ancestral branch, with a possible monophyletic origin. In this study, new contributions to the knowledge of evolutionary patterns facing by Tetraodontiformes are provided and discussed under cytotaxonomyc, genomic and evolutionary perspectives.

DERSU UZALA Hibridação Homem-Natureza

Esta disertación explora de qué forma las hibridaciones entre ser humano y ambientes naturales no urbanos contribuyen a configurar las estrategias de atención, de construcción de conocimiento y de interacción con el mundo del sujeto y cómo, recursivamente, las actitudes perceptivo-cognitivas y las maneras de acercarse a lo real, de imputar sentido a los fenómenos y de interactuar con el ambiente practicadas por el sujeto condicionan y contribuyen a definir las hibridaciones entre humanos y no humanos. Lo que guía esa exploración es el concepto de híbrido que, inspirándome en Bruno Latour (2008), concibo como una asociación entre elementos sin características inherentes, compenetrados, que se redefinen, recrean e reconfiguran recíprocamente. Utilizo como operadores cognitivos una narrativa literaria y una cinematográfica: el libro autobiográfico Dersu Uzala del escritor y explorador ruso Vladimir Klavdievich Arseniev (1872-1930), publicado por primera vez en 1923, y la película homónima del director japonés Akira Kurosawa (1910-1998), lanzada en 1975. Estas obras reconstruyen tres expediciones realizadas por Arseniev a principios del siglo XX en la región siberiana del Ussuri que tuvieron como guía al cazador nómada de etnia gold Dersu Uzala, con quien el escritor construyó una profunda amistad. La elección de hacer dialogar en el mismo plan a dos modos complementares de conocimiento, arte y ciencia, se fundamenta en la concepción de Edgar Morin (2003b) de la literatura y el cine como escuelas de vida y de complejidad humana y en la visión de Claude Lévi- Strauss (2007) del arte como modelo reducido que favorece una mirada más abarcadora sobre los fenómenos. Inicialmente, pongo en relación mi investigación con los trabajos de Silmara Lídia Marton (2008) y Samir Cristino de Souza (2009), que analizaron las estrategias de construcción de conocimiento y de interacción con el mundo de un habitante de la Laguna de Piató (Municipio de Assú, Estado de Rio Grande do Norte, Brasil), Francisco Lucas da Silva, y muestro algunas analogías entre estas y las de Dersu Uzala, ambas productos de determinadas hibridaciones con el ambiente. A continuación, exploro las implicaciones cognitivas de la amistad de Arseniev con el cazador gold, metáfora/encarnación del diálogo posible entre saberes de matrices diferentes. En un tercer momento, dialogando con pensadores que se interrogaron sobre el trinomio hombre-naturaleza-representaciones y con las narrativas de Arseniev (1997) y Kurosawa (1975), reflexiono sobre las ideas de híbrido, de humano y no humano, de vivo y no vivo, de proximidad y distancia del sujeto con respecto a otros sistemas de lectura del mundo, de relación directa y mediada con lo real, de ambientes naturales urbanos y no urbanos. A seguir, incursiono en el libro de Arseniev y en el largometraje de Kurosawa intentando identificar qué factores más contribuyeron para configurar las estrategias de conocimiento y de interacción con el ambiente manifestadas por el explorador y por el cazador gold y, recursivamente, de qué forma esas estrategias contribuyeron a definir sus hibridaciones con el ambiente siberiano. Por último, a partir de las reflexiones tejidas a lo largo del trabajo, me interrogo sobre lo que ellas pueden decirnos sobre nuestra forma de interactuar con la naturaleza no humana y sobre el diálogo entre distintas formas de percibir, conocer y relacionarse con el mundo

Padrões cariotípicos em tetraodontiformes (Osteichthypes) :redução genômica e mecanismos de diversificação

The Tetraodontiformes order is composed for about 400 species of fish, distributed in ten families, with circuntropical distribution. The morphologic diversity of each family reflects in, part, the different levels of specialization. This group represents an ancestry after-Perciformes and constitutes the last branch of the diffusion of the Teleósteos, occupying a position of prominence. The phylogenetics relationships of the Tetraodontiformes exist diverse works examining and, in all, these families are recognized as groups brothers, being Diodontidae next to Tetraodontidae and Balistidae next to Monacanthidae. Although it possesss a representative number of species, the works involving of the families Balistidae and Monacanthidae are few exemplary, especially species of oceanic islands. In this work cytogenetic studies in five species had been analyzed Cantherhines macrocerus, Cantherhines pullus (Monacanthidae), Melichthys niger (Balistidae), Sphoeroides testudíneus (Tetraodontidae) and Chilomycterus antennatus (Diodontidae); through conventional coloration, Ag-NORs and C banding. Ahead of the different karyological trends of evolution presented by the Tetraodontiformes, the present work also searched to verify the relation existence enters the total size of the chromosomes with the amount of DNA in these groups of Tetraodontiformes. For such, they had been correlated the total size of the chromosomes of these species, with values of content of available DNA in literature. The cytogenetics analyses for the species C.macrocerusJ C.pullus (Monacanthidae) and M.niger (Balistidae), had disclosed 40 chromosomes, all acrocentrics. All possess only one pair of NORs and pericentromeric heterochromatin. For S.testudíneus the found dyploid number was equal 2n=46, with NF=78 (16m+18sm+8st+4a), while that for C.antennatus it possesss 2n=50, with NF=76 (4m+22st+24a). Both species possess simple NORs and pericentromeric heterochromatin blocks. In M.niger, the presence of positive marking (heterochromatin and NOR) in the secondary constriction in the second chromosomic pair suggesting the occurrence of a rearrangement, possibly a fusing involving these homologous ones, indicating that these events had been important for the establishment of the karyological history of this group. A maintenance of the chromosomic constancy found in the populations of C.macrocerus (Monacanthidae) and S.testudineus (Tetraodontidae) perhaps if must for the aiding of the gene flow through oceanic chains. These data contrast with the differentiated kinds of chromosomes of C.antennatus between the Northeast coast and Southeastern, suggesting that the ecological standards of each species, added to the conditions of the marine environment, can be responsible for the karyological delineation of each species. The found characteristics for the species C.macrocerus, C.pullus, M.niger, S.testudineus and C.antennatus add it the available data for other species of Tetraodontiformes. From the data gotten in the present study, it can be inferred that the DNA content possesss direct relation with the total length of the chromosomes