Mutagenic potential evaluation of the water of a river that receives tannery effluent using the Allium cepa test system

Several studies are being conducted to assess the toxicity and cytotoxicity of water bodies receiving industrial and domestic effluents, using the Allium cepa test. To assess the toxicity and mutagenicity of water possibly contaminated with chromium, derived from tannery activities, seasonal water samplings were performed in 2001 and 2002 at five different sites along the Sapucaizinho river, Municipality of Patrocinio Paulista, State of São Paulo, Brazil. A. cepa seeds were used as the test material and were submitted to germination in waters from the different collection sites, in Milli-Q water (negative control) and in aqueous solution of chromium (positive control). For the determination of cell division rates and mitotic irregularities, slides were prepared with root tip cells according to the standard Feulgen methodology. The results showed that the collection sites most heavily compromised by chromium emission presented low mitotic indices and a higher frequency of mitotic changes such as irregular anaphases (disorganized, multipolar, laggard), cells with chromosomal adherences, cells with micronuclei, and binucleate and/or multinucleate cells. © 2004 The Japan Mendel Society.

Analysis of the nucleolar cycle in the seminiferous epithelium of rodents

The nucleolus is a subcompartment of the nucleus and the site of ribosome biogenesis. During the mitotic and meiotic cell cycles, a disorganization and later reorganization of the nucleolar material occur, an event called nucleologenesis. In the spermatogenesis of mammals and other vertebrates, there is evidence of the disorganization of the nucleolus at the end of meiosis I, which supplies material for the cytoplasmic formation of an organelle called the chromatoid body (CB). The CB is a structure characteristic of spermatogenic cells and seems to be responsible for RNA metabolism in these cells and for some events of spermiogenesis, such as the formation of the acrosome, cellular communication between spermatids, and the formation of the spermatozoon middle piece and tail. The aim of this paper was to obtain information about the cytochemical and ultrastructural nature of the nucleolar cycle and the distribution of cytoplasmic RNAs in the seminiferous tubule cells of Rattus novergiucus, Mus musculus and Meriones unguiculatus. The testis was fixed in Bouin and Karnovsky solutions for conventional histological analysis and for cytochemical study that included: periodic acid-Schiff, hematoxylin-eosin, Feulgen reaction, silver-ion impregnation, Gomori's reticulin stain, toluidine blue, modified method of critical electrolyte concentration, and basic and acid fast green. The blocks of testis fixed in glutaraldehyde were used for ultrastructural analysis by transmission electron microscopy. Ultrathin sections were double-stained with uranyl acetate and lead citrate. All the techniques used provided information on the origin and function of the CB in the spermatogenic cells. Therefore, considering the persistence of the RNA and nucleolar ribonucleoproteins during spermatogenesis of Rattus novergicus, Mus musculus and Meriones unguiculatus, our findings corroborate the statement that these molecular complexes are very important in the spermiogenesis phases. It can be suggested that these ribonucleoprotein corpuscles (chromatoid bodies) are of nuclear origin and have a role in the successive series of events that occur in the formation of the spermatozoon. Furthermore, these results reinforce the conservation of the mechanisms involved in preserving necessary levels of protein stocks in different stages of cell differentiation, from spermatid to spermatozoon, in these rodent species. ©FUNPEC-RP.

Spermatogenesis of Zaprionus indianus and Zaprionus sepsoides (Diptera, Drosophilidae): Cytochemical, structural and ultrastructural characterization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Brain morphophysiology of Africanized bee Apis mellifera exposed to sublethal doses of imidacloprid

Several synthetic substances are used in agricultural areas to combat insect pests; however, the indiscriminate use of these products may affect nontarget insects, such as bees. In Brazil, one of the most widely used insecticides is imidacloprid, which targets the nervous system of insects. Therefore, the aim of this study was to evaluate the effects of chronic exposure to sublethal doses of imidacloprid on the brain of the Africanized Apis mellifera. The organs of both control bees and bees exposed to insecticide were subjected to morphological, histochemical and immunocytochemical analysis after exposure to imidacloprid, respectively, for 1, 3, 5, 7, and 10 days. In mushroom bodies of bees exposed to imidacloprid concentrations of LD50/10 and in optic lobes of bees exposed to imidacloprid concentrations of LD 50/10, LD50/100, and LD50/50, we observed the presence of condensed cells. The Feulgen reaction revealed the presence of some cells with pyknotic nuclei, whereas Xylidine Ponceau stain revealed strongly stained cells. These characteristics can indicate the occurrence of cell death. Furthermore, cells in mushroom bodies of bees exposed to imidacloprid concentrations of LD50/10 appeared to be swollen. Cell death was confirmed by immunocytochemical technique. Therefore, it was concluded that sublethal doses of imidacloprid have cytotoxic effects on exposed bee brains and that optic lobes are more sensitive to the insecticide than other regions of the brain. © 2013 Springer Science+Business Media New York.

Análise morfológica e histoquímica do corpo gorduroso e dos túbulos de Malpighi de operárias adultas de Scaptotrigona postica (Latreille, 1807) (Hymenoptera, Apidae) tratadas com fipronil e ácido bórico

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Avaliação quantitativa de micronúcleos na citologia esfoliativa da mucosa bucal de pacientes dependentes químicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência das alterações testiculares diagnosticadas pela histopatologia sobre as características biométricas, morfométricas e seminais em touros da raça nelore

Pós-graduação em Medicina Veterinária - FMVZ

Estudo comparativo das características citogenéticas e moleculares de Triatoma maculata e Triatoma pseudomaculata (Triatominae, Heteroptera)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise da freqüência de micronúcleos frente à utilização de colutórios bucais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização do ciclo nucleolar e da formação do corpo cromatóide na espermatogênese de alguns vertebrados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Espermatogênese de Zaprionus indianus e Zaprionus sepsoides (Diptera: Drosophilidae): caracterização citoquímica, estrutural e ultraestrutural

Pós-graduação em Genética - IBILCE

Estudo biotecnológico, citogenético e molecular em espécies de orquídeas endêmicas da flora brasileira

Pós-graduação em Biociências - FCLAS

Cytogenetic and morphologic approaches of hybrids from experimental crosses between Triatoma lenti Sherlock & Serafim, 1967 and T. sherlocki Papa et al., 2002 (Hemiptera: Reduviidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Is there post-meiotic transcriptional activity during hemipteran spermiogenesis?

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

Recursos hídricos sob influência de efluentes industriais do polo industrial de Santa Gertrudes

Efluentes industriais e domésticos podem conter agentes químicos e biológicos que, em elevadas concentrações, causam danos aos ecossistemas aquáticos e à saúde ambiental. Um dos efeitos mais nocivos desses agentes poluidores é a sua capacidade de induzir alterações celulares. O uso de testes específicos capazes de detectar o potencial tóxico de substâncias químicas caracteriza-se em uma importante estratégia para avaliação ambiental. Neste contexto, o presente estudo teve como objetivo avaliar os potenciais citotóxico, genotóxico e mutagênico de amostras de água de recursos hídricos da cidade de Santa Gertrudes-SP, relacionada com recebimento de efluentes de atividade ceramista, por meio de ensaios realizados com o sistema-teste de Allium cepa. Foram realizados testes com amostras de água coletadas no córrego Itaqui, após despejos de efluente de indústria cerâmica e em duas nascentes, tanto em período chuvoso como de seca. Para a análise dos parâmetros de toxicidade descritos acima, sementes de A. cepa foram expostas à germinação nas amostras das águas coletadas. Quando as radículas atingiram 2 cm de comprimento, os meristemas foram fixados em solução de Carnoy 3:1, para serem utilizadas nas avaliações das possíveis alterações dos índices de germinação e mitóticos, bem como de indução de aberrações nucleares e cromossômicas. Além disso, também foram avaliadas, como outro parâmetro indicativo de mutagenicidade, as frequências de micronúcleos em células F1 de A. cepa. O controle negativo foi realizado em água (osmose reversa) e o controle positivo em metilmetanosulfonato (MMS). O material fixado foi corado pela reação de Feulgen e as lâminas foram preparadas, utilizando as porções meristemática e F1 das raízes de A. cepa. As análises foram realizadas em microscópio de luz, por meio da contagem de alterações nucleares (micronúcleos e brotos) e de aberrações cromossômicas...