Comparative cytogenetic analysis of marine needlefishes (Beloniformes) from southern Brazil.

Cytogenetic studies have assisted in the taxonomic classification of organisms, especially those involving species with highly similar morphologic characteristics, or so-called cryptic species. Strongylura marina and Strongylura timucu collected from Paranaguá Bay, Paraná Coast in Southern Brazil are considered cryptic species, and the identification of interspecific variations based on the number and/or morphology of its chromosomes may serve as differentiating cytotaxonomic markers. Chromosomes of the two species were subjected to different banding and staining methods (C-, Ag-, and DAPI-CMA3), as well as chromosomal mapping of major rDNA (45S), revealed with an 18S probe by fluorescence in situ hybridization (FISH). The pattern of distribution of constitutive heterochromatin showed distinct features involving the pericentromeric and telomeric bands in both species. In S. marina, chromosome 1 represents the main species-specific marker, appearing almost entirely heterochromatic. In both species, the 45S rDNA is located at terminal region of the short arm of the chromosome 6, as detected by silver nitrate staining and FISH. Despite the apparent conserved diploid number of 48 chromosomes, data on the karyotype microstructure characterize the cytogenetic profile of the genus and may allow the establishment of cytotaxonomic and evolutionary inferences for these fishes.

Serological and molecular investigation of viral agents in freeliving jaguars of the Pantanal wetlands, state of Mato Grosso, Brazil / Investigação sorológica e molecular de agentes virais em onças-pintadas de vida livre no Pantanal de Mato Grosso, Brasil

This study investigates the exposure of free-living jaguars from two federal protected areas in the Pantanal of Mato Grosso, Brazil, to a variety viral agents. These viral agents, particularly causing zoonotic diseases, were analyzed using serological and molecular methods. None of the jaguars was positive by RT-PCR for the molecular detection of avian influenza and West Nile Fever (WNF). Only one animal was serologically positive for Eastern Equine Encephalitis (EEE) by virus neutralization test in VERO cell cultures, representing the first reported case of jaguar exposure to EEE virus. However, all the animals were negative for Western Equine Encephalitis (WEE) virus and Venezuelan Equine Encephalitis (VEE) virus. Eleven jaguars were tested by two tests for the detection of antibodies against rabies virus (Simplified Fluorescent Inhibition Microtest ­ SFIMT and Rapid Fluorescent Focus Inhibition Test ­ RFFIT), resulting in five positive animals, two animals in each test and one in both serological tests. Furthermore, three out of 14 samples subjected to the neutralization test were positive for antibodies against canine distemper virus (CDV), and 15 out of 17 samples subjected to the hemagglutination-inhibition test (HI) were positive for antibodies against canine parvovirus (CPV). In view of the findings of this study, it is unlikely that the viruses examined here represent a threat to the jaguar populations in this region.(AU)

Este estudo investigou a exposição de onças-pintadas de vida livre a agentes virais selecionados em duas unidades de conservação federais no Pantanal de Mato Grosso, Brasil. Para a análise desses agentes virais, a maioria de caráter zoonótico, foram utilizados métodos sorológicos e moleculares. Nenhuma das onze onças-pintadas examinadas foi positiva na técnica de real-time RT-PCR para a detecção molecular dos agentes da Influenza aviária e Febre do Nilo Ocidental (WNF). Somente um animal foi positivo sorologicamente para a o vírus da Encefalite Equina do Leste (EEE) pela Microtécnica de vírus neutralização em culturas de células VERO, sendo este o primeiro relato da exposição de onças-pintadas. Todos os animais examinados s foram negativos para o vírus da Encefalite Equina do Oeste (WEE) e Venezuelana (VEE). Amostras de soro colhidas de 11 onças-pintadas foram submetidas a adois testes distintos para a detecção de anticorpos contra o vírus da raiva (Teste Rápido de Inibição de Foco de Fluorescência ­ RFFIT e Microteste Simplificado de Inibição da Fluorescência - SFIMT), resultando em cinco animais positivos, dos quase dois positivos para cada teste e um positivo quando submetido aos dois testes sorológicos. Além disso, três das 14 amostras submetidas a técnica de soroneutralização foram positivas para a pesquisa de anticorpos contra o vírus da cinomose (CDV) e 15 amostras positivas das 17 analisadas para a pesquisa de anticorpos contra o parvovírus canino (CPV) foram identificadas pela técnica de Inibição da Hemaglutinação (HI). De acordo com os resultados deste estudo, é pouco provável que os agentes virais aqui analisados representem ameaça à população de onçaspintadas nesta região.(AU)

Detection of Leptospira spp. and Brucella abortus antibodies in free-living jaguars (Panthera onca) in two protected areas of northern Pantanal, Brazil.

This study aimed to assess the exposure of free-living jaguars (Panthera onca) to Leptospira spp. and Brucella abortus in two conservation units in the Pantanal of Mato Grosso, Brazil. The presence of antibodies in blood samples of eleven jaguars was investigated using autochthonous antigens isolated in Brazil added to reference antigen collection applied to diagnosis of leptospirosis by Microscopic Agglutination Test (MAT). The Rose Bengal test was applied for B. abortus antibodies. Two (18.2%) jaguars were seroreactive for the Leptospira spp. antigen and the serovar considered as most infective in both animals was a Brazilian isolate of serovar Canicola (L01). All jaguars were seronegative for B. abortus. These data indicate that the inclusion of autochthonous antigens in serological studies can significantly increase the number of reactive animals, as well as modify the epidemiological profile of Leptospira spp. infection.

Cytogenetic study of heptapterids (Teleostei, Siluriformes) with particular respect to the Nemuroglanis subclade.

The catfish family Heptapteridae (order Siluriformes) is endemic to the Neotropics and is one of the most common of the fish families in small bodies of water. Although over 200 species have been identified in this family, very few have been characterized cytogenetically. Here, we analyze the chromosome genomes of four species of Heptapteridae: Cetopsorhamdiaiheringi (Schubart & Gomes, 1959), 2n = 58, comprising 28 metacentric (m) + 26 submetacentric (sm) + 4 subtelomeric (st) chromosomes; Pimelodellavittata (Lütken, 1874), 2n = 46, comprising 16m + 22sm + 8st; Rhamdiapropequelen (Quoy & Gaimard, 1824), 2n = 58 comprising 26m + 16sm + 14st + 2 acrocentric; and Rhamdiopsispropemicrocephala (Lütken, 1874), 2n = 56, comprising 12m + 30sm + 14st. The nucleolus organizer regions (NORs) were located in a single chromosome pair in all species. The two species that belonged to the subclade Nemuroglanis, Cetopsorhamdiaiheringi and Rhamdiapropequelen, had a diploid chromosome number of 58 and an interstitial NOR adjacent to a C(+) block located on one of the larger chromosome pairs in the complement. Our results from conventional cytogenetic techniques in combination with FISH using 18S and 5S rDNA probes corroborated the taxonomical hypothesis for the formation of the Nemuroglanis subclade.

Exposure of free-living jaguars to Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in the Brazilian Pantanal.

Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are related apicomplexan parasites that cause reproductive and neurological disorders in a wide range of domestic and wild animals. In the present study, the immunofluorescence antibody test (IFAT) was used to investigate the presence of antibodies against T. gondii, N. caninum and S. neurona in the sera of 11 free-living jaguars (Panthera onca) in two protected areas in the Pantanal region of Mato Grosso state, Brazil. Ten jaguars (90.9%) showed seropositivity for T. gondii, eight (72.7%) for S. neurona, and seven (63.6%) for N. caninum antigens. Our findings reveal exposure of jaguars to these related coccidian parasites and circulation of these pathogens in this wild ecosystem. To the best of our knowledge, this is the first serological detection of N. caninum and S. neurona in free-living jaguars.

Exposure of free-living jaguars to Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in the Brazilian Pantanal / Exposição de onças-pintadas a Toxoplasma gondii, Neospora caninum e Sarcocystis neurona no Pantanal brasileiro

Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are related apicomplexan parasites that cause reproductive and neurological disorders in a wide range of domestic and wild animals. In the present study, the immunofluorescence antibody test (IFAT) was used to investigate the presence of antibodies against T. gondii, N. caninum and S. neurona in the sera of 11 free-living jaguars (Panthera onca) in two protected areas in the Pantanal region of Mato Grosso state, Brazil. Ten jaguars (90.9%) showed seropositivity for T. gondii, eight (72.7%) for S. neurona, and seven (63.6%) for N. caninum antigens. Our findings reveal exposure of jaguars to these related coccidian parasites and circulation of these pathogens in this wild ecosystem. To the best of our knowledge, this is the first serological detection of N. caninum and S. neurona in free-living jaguars.

Toxoplasma gondii, Neospora caninum e Sarcocystis neurona são coccídios relacionados responsáveis por causar desordens reprodutivas e neurológicas em uma ampla variedade de animais domésticos e selvagens. No presente estudo, a Reação de Imunofluorescência Indireta (RIFI) foi utilizada para investigar a presença de anticorpos contra T. gondii, N. caninum e S.neurona em soros de 11 onças-pintadas de vida livre (Panthera onca), provenientes de duas áreas protegidas na região do Pantanal do Estado de Mato Grosso, Brasil. Dez (90,9%), sete (63,6%) e oito (72,7%) onças amostradas foram soropositivas para T. gondii, N. caninum e S. neurona, respectivamente. Os resultados indicam a exposição a esses coccídios relacionados entre as onças-pintadas e a circulação ambiental desses patógenos nesse ecossistema selvagem. Este é o primeiro relato da detecção sorológica de N. caninum e S. neurona em onças-pintadas de vida livre.

Chromosomal evidence of downstream dispersal of Astyanax fasciatus (Characiformes, Characidae) associated with river shed interconnection.

In the 1960s, as a part of the construction of the Furnas Hydroelectric Power Dam, Minas Gerais, Brazil, the Rio Piumhi was diverted from the Rio Grande drainage to the São Francisco River basin, with the resulting introduction of species from one basin to the other. Chromosomal characteristics of various populations of Astyanax fasciatus sensu Eigenmann from the transect region were studied using cytogenetic techniques, with the goal to identify and map the dispersal of invasive species in the Rio São Francisco. Populations of the Rio Grande and Rio Piumhi are distinct from those of the São Francisco basin based on chromosome markers associated to the heterochromatin, Ag-NORs, 18S rDNA, 5S rDNA, and As-51 satellite DNA sites. Individuals with karyomorph originally present in the Piumhi drainage are now present in the São Francisco basin, downstream from the transposition channel. This expansion of the distribution corroborates a hypothesis of progressive substitution of native populations by the invasive Piumhi form.

Characterization of the constitutive heterochromatin of Astyanax sp. D (Characiformes: Characidae) from the Upper Iguaçu River (PR).

Chromosomal characterization of constitutive heterochromatin was performed in Astyanax sp. D, a species found in the Iguaçu river, using C-banding, fluorescent in situ hybridization (FISH) of the repetitive DNA family As51, localization of the 18S rDNA sites and base-specific fluorochromes. The sites of the satellite DNA coincide with large heterochromatic blocks present in this species, namely CMA3- and DAPI-. The many 18S rDNA sites are CMA3+. Similarity between the large heterochromatic blocks is suggested, as well as the identification of two types of heterochromatin, one related to the 18S rDNA domains and the other to the As51 regions.

Chromosomal studies of five species of the marine fishes from the Paranaguá Bay and the karyotypic diversity in the marine teleostei of the Brazilian coast

In this study, five species of marine fishes from the Paranaguá Bay in the Brazilian coast were evaluated. Eucinostomus argenteus and Diapterus rhombeus (Gerreidae) presented 48 chromosomes, all of which more acrocentric (FN = 48); Strongylura timucu and S. marina (Belonidae) also presented 48 chromosomes, but with a higher karyotypic complexity than the Gerreidae, 10M+2SM+36A (FN = 60) and 4M+44A (FN = 52), respectively. The fifth species, Mugil curema (Mugilidae), different than the others, presented only 28 chromosomes 20M+4ST+4A (FN = 48). The species presented diversity in the karyotypic macro-structure, which should be relevant for the cytotaxonomy and the evolution of this group of the vertebrate.

Nas últimas décadas tem ocorrido no Brasil um incremento de estudos cariotípicos em peixes marinhos. Atualmente são conhecidos os cariótipos de 118 espécies, distribuídas em 43 famílias e 80 gêneros. Foram estudadas cinco espécies de peixes marinhos do complexo estuarino da Baía de Paranaguá na costa brasileira. Eucinostomus argenteus e Diapterus rhombeus (Gerreidae), apresentaram 48 cromossomos todos acrocêntricos (NF = 48); Strongylura timucu e S. marina (Belonidae) apresentaram 48 cromossomos, porém com complexidade cariotípica maior do que apresentada pelos gerreídeos, 10M+2SM+36A (NF = 60) e 4M+44A (NF = 52), respectivamente. A quinta espécie, Mugil curema (Mugilidae), ao contrário das outras quatro espécies aqui analisadas, apresentou apenas 28 cromossomos 20M+4ST+4A (NF = 48). Apesar da tendência em se verificar um cariótipo constituído por 48 cromossomos em teleósteos marinhos, as espécies aqui analisadas apresentam uma diversidade para a macroestrutura cariotípica a ser considerada para a citotaxonomia e evolução desse grupo de vertebrados.

Population analysis of a chromosome polymorphism in Astyanax (Teleostei, Characiformes) species endemic to the Iguaçu River

Chromosomal analyses were performed in the fish Astyanax sp.D collected from three different points: two streams from the right bank and one from the left bank of the Upper Iguaçu River, Paraná State, Brazil. The individuals from all localities possess 2n = 50 chromosomes and a FN = 84 (4m+24sm+6st+16a). The C-banding pattern was similar in all populations. However, within each population, an interindividual variation concerning the number and localization of heterochromatic bands was observed. Some of these variations were quantified in each population, and the results indicate that the samples were not different when studying the variable frequencies. Considering that Astyanax sp.D is typical in the headwaters of the Iguaçu River, these results were not expected. The data indicate that gene flow is occurring and that the Iguaçu River is not an ecological barrier among the Astyanax sp. D populations.

Cytotaxonomic and evolutionary considerations about karyotipic data of fishes from the Iguaçu River Basin in South of Brazil

The cytogenetic data available in the literature about the ichthyofauna of the Iguaçu River basin were analyzed in this review. The ichthyofauna was characterized by the high level of endemism and by the low diversity of species. Twenty-four of the eighty-one species were already karyotyped; six Characiformes, fourteen Siluriformes and four Perciformes. The chromosomal data showed the taxonomic and systematic complexity of the groups. Hypothesis related to the evolution of some Characiformes and Siluriformes groups from the Iguaçu River are proposed, as well as the utilization of karyotypic data for cytotaxonomy.

Nesta revisão são analisados os dados citogenéticos disponíveis na literatura relativos à ictiofauna da bacia do Rio Iguaçu, a qual é caracterizada pelo alto grau de endemismo e pela baixa diversidade de espécies. Das oitenta e uma espécies conhecidas, vinte e quatro já foram cariotipadas sendo 6 Characiformes, 14 Siluriformes e 4 Perciformes. Os dados cromossômicos evidenciam a complexidade taxonômica e sistemática dos grupos. São propostas hipóteses relacionadas à evolução de alguns grupos de Characiformes e Siluriformes do Rio Iguaçu, assim como o aproveitamento de dados cariotípicos para a citotaxonomia.

Cytotaxonomy, heterochromatic polymorphism and natural triploidy of a species of Astyanax (Pisces, Characidae) endemic to the Iguaçu river basin

Cytogenetic analysis with Astyanax sp. D revealed a karyotype of 2n=50 with 2M+26SM+6ST+16A, besides a triploid specimen showing 2n=75 chromosomes (3M+39SM+9ST+24A). C-banding strongly stained the terminal regions of several SM-ST-A chromossomes. Two pairs of acrocentric chromosomes presented interstitial heterochromatin, this state being polymorphic and occuring due to possible paracentric inversions. The results obtained with the AluI restriction enzyme and A3 chromomycin were similar to the C-banding. Relationships were proposed between Astyanax sp. D and A. scabripinnis, as well as considerations for a possible origin of the triploid specimen (2n=3x=75). When comparing the present results with cytogenetic features of other endemic Astyanax species in the Iguaçu river (A. sp. B and C), a clear differentiation was observed between them, indicating cytogenetics as an important cytotaxonomic tool.

Análises citogenéticas em Astyanax sp. D evidenciaram 2n=50 cromossomos e um cariótipo com 2M+26SM+6ST+16A. O bandamento C destacou as regiões teloméricas de diversos cromossomos SM-ST-A. Dois pares de cromossomos acrocêntricos possuem heterocromatina intersticial, sendo este estado polimórfico decorrente de prováveis inversões paracêntricas. O resultados obtidos com a enzima de restrição AluI e a Cromomicina A3 foram semelhantes aos do bandamento C. São propostas relações de parentesco entre Astyanax sp. D e Astyanax scabripinnis, bem como considerações sobre a possível origem do exemplar triplóide (2n=3x=75). Ao comparar os resultados deste trabalho com outras espécies de Astyanax do Rio Iguaçu, estas espécies se tornam claramente distinguíveis, evidenciando a citogenética como uma importante ferramenta taxonômica.

Karyotypic characterization of Hydromedusa tectifera (Testudines, Pleurodira) from the upper Iguaçu River in the Brazilian state of Paraná

We present the karyotypic characterization of 26 specimens of the side-necked turtle Hydromedusa tectifera collected in the upper Iguaçu River, Paraná state, Brazil. The turtles were cytogenetically analyzed using Giemsa staining and other banding techniques (C, G, Ag-NOR and CMA3) as well as fluorescence in situ hybridization (FISH) with a rDNA 18S probe. All the specimens showed a diploid number of 58 composed of 22 macro and 36 microchromosomes. The Ag-NOR, CMA3 and FISH techniques permitted the identification and characterization of the chromosome pairs bearing nucleolus organizer regions (NORs), while G-banding facilitated a better recognition and pairing of macrochromosomes. These data agree with some information available in the literature and should be very useful for further cytotaxonomic and cytosystematic studies.