Estudo dos cromossomos de espécies alocadas em incertae sedis (Characiformes, Characidae) com o uso de diferentes marcadores citogenéticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nuclear-follower foraging associations among Characiformes fishes and Potamotrygonidae rays in clean waters environments of Teles Pires and Xingu rivers basins, Midwest Brazil

Por meio de observações sub e supra-aquáticas foram registradas associações alimentares do tipo nuclear-seguidor entre três espécies de peixes characiformes - Chalceus epakros, Hemiodus semitaeniatus e Hemiodus unimaculatus - e uma espécie de raia de água doce - Potamotrygon orbignyi - nas bacias dos rios Teles Pires e Xingu, no Centro-Oeste do Brasil. Os peixes teleósteos foram observados seguindo as raias quando estas revolviam o substrato à procura de invertebrados, formando discretas nuvens de sedimento. Essas situações atraíram os peixes que se aproximaram das raias para se alimentar de pequenas presas e outros tipos de alimentos expostos desta forma. Esse é um típico exemplo de relação comensal onde um participante é beneficiado enquanto o outro não é prejudicado e representa o segundo registro na literatura de associação alimentar do tipo nuclear-seguidor entre raias potamotrigonídeas e peixes teleósteos, demonstrando o potencial de estudos naturalísticos para a descoberta de novas interações envolvendo espécies de peixes de água doce.

Age-related ultrasonography, cytology, and microbiologic exam of canine prostate

Obtiveram-se parâmetros fisiológicos que pudessem ser utilizados como referência para diagnóstico e prognóstico confiáveis de doença prostática em cães. Trinta e seis cães, sem sinais clínicos de doença prostática ou distúrbios reprodutivos, foram distribuídos em três grupos de acordo com a idade.Os animais foram submetidos à colheita manual de sêmen para exames microbiológicos, à ultrassonografia transabdominal, para avaliar as dimensões, a ecogenicidade e a ecotextura prostática, e à punção aspirativa com agulha fina, para análise citológica e microbiológica. A ultrassonografia revelou que a forma predominante da próstata foi globosa, com superfície de contorno regular. As dimensões variaram de acordo com a idade, sendo pequena em animais jovens e grande nos animais idosos. Houve correlação positiva entre as dimensões prostáticas e o peso corporal. Os exames microbiológicos detectaram microrganismos no plasma seminal de 11 cães e no tecido prostático aspirado de 10 animais, embora eles fossem saudáveis. A citologia não revelou nenhuma alteração inflamatória, proliferativa ou neoplásica nos cães jovens e de meia idade, mas, em três cães idosos foram encontrados sinais de hiperplasia/hipertrofia. Foi observada correlação positiva entre a idade e a área celular e correlação negativa entre a relação núcleo:citoplasma e a dimensão craniocaudal.

Comparative evaluation of the susceptibility of cultivated fishes to the natural infection with myxosporean parasites and tissue changes in the host

O objetivo deste estudo foi avaliar a susceptibilidade de 4 importantes peixes cultivados a parasitos esporozoários. Os peixes foram coletados bimestralmente de um tanque de cultivo, durante 1 ano. Myxobolus colossomatis e Henneguya piaractus foram encontrados nos órgãos internos e brânquias, respectivamente. A incidência de ambos os parasitos foi de 97,3% em pacu (Piaractus mesopotamicus), 33,3% no híbrido tambacu (Piaractus mesopotamicus x Colossoma macropomum), 5,6% em tambaqui (Colossoma macropomum) e 0% em carpa (Cyprinus carpio). Pacu foi o peixe mais susceptível, encontrando-se parasitado 79,2% nas brânquias, 66,7% nos rins e 50% no baço. A análise histopatológica das brânquias mostrou hemorragias, reação inflamatória com células mononucleares, fibroblastos e hiperplasia das células basais e mucosas.

Fine needle aspiration (FNA) cytology of pilomatrixoma: report of 14 cases and review of the literature

We describe 14 cases of pilomatrixoma which were diagnosed preoperatively on FNA cytology. In contrast to the literature, our series showed male preponderance and some of the tumours in unusual locations such as thigh and breast. In three patients the rumours were larger than 5 cm. The clinical diagnosis varied from tumour not otherwise defined to sarcoma. The cytologic presentation had features which allowed a correct diagnosis in all cases and included basaloid cells surrounded by delicate pink fibres, shadow cells, giant cells, naked nuclei and calcium deposits. It is concluded that the FNA cytology of pilomatrixoma is characteristic and will allow a conclusive diagnosis even in cases with an aberrant clinical presentation.

Measurement of thrombopoietic activity through the quantification of megakaryocytes in bone marrow cytology and reticulated platelets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Testicular fine needle aspiration cytology from a stallion with testicular degeneration after external genitalia trauma.

A seven-year-old Quarter Horse had a serious external genitalia trauma with severe swelling of ventrum, penis, prepuce and scrotum after falling over a fence. Appropriated treatment was rapidly started after clinical examination. During recovery period, the spermatogenesis assess by semen evaluation was not possible due to stallion's inability to ejaculate. Therefore, for testicular evaluation fine needle aspiration cytology (FNAC) was performed. The first FNAC showed a deviation of germ cell line towards immature cells, mainly by primary spermatocytes (59.5%) with very few late spermatids and spermatozoa (2.5% each), and an increased Sertoli cells/germ cells ratio (478/100), which characterized testicular degeneration. One month after the first FNAC, the second exam presented a drastic decrease of Sertoli cells/germ cells ratio (7/100) and marked increase of mature cell number, specially by early and late spermatids (50% and 24.5%, respectively). In this case, the results of both FNAC could demonstrate a partial recovery of spermatogenesis activity. Two months later, the stallion had mated two mares successfully and they became pregnant. In conclusion, the adequate treatment allowed a complete recovery of the stallion's reproductive function, and since semen collection was impossible during treatment, testicular FNAC showed to be an efficient diagnostic method for evaluating acute damage in the spermatogenesis.

Evaluation testicular fine needle aspiration cytology and serum testosterone levels in dogs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Coalescence of teeth in fishes

In this paper the concept of coalescence of teeth previously defined for the Tetraodontoid fishes is extended to some other teleostomes. Comments are made on the «dentigerous plates» of non-teleostomian fishes and on the dermal plates bearing odontodes found in some fossil groups.

Two 5S rDNA arrays in Neotropical fish species: is it a general rule for fishes ?

In this paper we describe Southern blot hybridization results probed with 5S rRNA genes for several Neotropical fish species representing different taxonomic groups. All the studied species showed a general trend with the 5S rDNA tandem repeats organized in two distinct size-classes. At the same time, data on 5S rDNA organization in fish genome were summarized. Previous information on the organization and evolution of 5S rRNA gene arrays in the genome of this vertebrate group are in agreement with the Southern results here presented. Sequences obtained for several fish species have revealed the occurrence of two distinct 5S rDNA classes characterized by distinct non-transcribed spacer sequences, which are clustered in different chromosomes in some species. Moreover, the 5S rDNA loci are generally distributed in an interstitial position in the chromosomes and they are usually not syntenic to the 45S rDNA. The presence of two classes of 5S rDNA in several non-related fish species suggests that this could be a common condition for the 5S rRNA gene organization in the fish genome.

Comparative chromosome mapping of 5S rDNA and 5SHindIII repetitive sequences in Erythrinidae fishes (Characiformes) with emphasis on the Hoplias malabaricus 'species complex'

Chromosomal localization of 5S rDNA and 5SHindIII repetitive sequences was carried out in several representatives of the Erythrinidae family, namely in karyomorphs A, D, and F of Hoplias malabaricus, and in H. lacerdae, Hoplerythrinusunitaeniatus and Erythrinus erythrinus. The 5S rDNA mapped interstitially in two chromosome pairs in karyomorph A and in one chromosome pair in karyomorphs D and F and in H. lacerdae. The 5SHindIII repetitive DNA mapped to the centromeric region of several chromosomes (18 to 22 chromosomes) with variations related to the different karyomorphs of H. malabaricus. on the other hand, no signal was detected in the chromosomes of H. lacerdae, H. unitaeniatus and E. erythrinus, suggesting that the 5SHindIII-DNA sequences have originated or were lost after the divergence of H. malabaricus from the other erythrinid species. The chromosome distribution of 5S rDNA and 5SHindIII-DNA sequences contributes to a better understanding of the mechanisms of karyotype differentiation among the Erythrinidae members.Copyright (c) 2007 S. Karger AG, Basel.

Genomic organization and evolution of the 5S ribosomal DNA in Tilapiini fishes

5S rDNA sequences present an intense dynamism and have proved to be valuable as genetic markers to distinguish closed related species and also in the understanding of the evolutionary dynamic of repetitive sequences in the genomes. In order to identify patterns of 5S rDNA organization and their evolution in the genome of fish species, such genomic segment was investigated in the tilapias Oreochromis niloticus and Tilapia rendalli, and in the hybrid O. urolepis hornorum x O. mossambicus. A dual 5S rDNA system was identified in the three analyzed tilapia samples. Although each 5S rDNA class was conserved among the three samples, a distinct 5S rDNA genome organization pattern could be evidenced for each sample. The presence of a dual 5S rDNA system seems to be a general trait among non-related teleost fish orders, suggesting that evolutionary events of duplication have occurred before the divergence of the main groups of teleost fishes.

PCR primed with minisatellite core sequences yields species-specific patterns and assessment of population variability in fishes of the genus Brycon

Minisatellite core sequences were used as single primers in polymerase chain reaction (PCR) to amplify genomic DNA in a way similar to the random amplified polymorphic DNA methodology. This technique, known as Directed Amplification of Minisatellite-region DNA, was applied in order to differentiate three neotropical fish species (Brycon orbignyanus, B. microlepis and B. lundii ) and to detect possible genetic variations among samples of the threatened species, B. lundii , collected in two regions with distinct environmental conditions in the area of influence of a hydroelectric dam. Most primers generated species-specific banding patterns and high levels of intraspecific polymorphism. The genetic variation observed between the two sampling regions of B. lundii was also high enough to suggest the presence of distinct stocks of this species along the same river basin. The results demonstrated that minisatellite core sequences are potentially useful as single primers in PCR to assist in species and population identification. The observed genetic stock differentiation in B. lundii associated with ecological and demographic data constitute a crucial task to develop efficient conservation strategies in order to preserve the genetic diversity of this endangered fish species.

Deep barcode divergence in Brazilian freshwater fishes: the case of the Sao Francisco River basin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative cytogenetics of cichlid fishes through genomic in-situ hybridization (GISH) with emphasis on Oreochromis niloticus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)