Environmental Genotoxicity Evaluation Using Cytogenetic End Points in Wild Rodents

Abstract

ArticlesWe analyzed cytogenetic end points in three populations of two species of wild rodents-Akodon montensis and Oryzomys nigripes-living in an industrial, an agricultural, and a preservation area at the Itajaí Valley, state of Santa Catarina, Brazil. Our purpose was to evaluate the performance of the following end points in the establishment of a genotoxic profile of each area: the polychromatic/normochromatic cell ratio; the mitotic index; the frequency of micronucleated cells both in the bone marrow and peripheral blood; and the frequency of cells with chromosome aberrations in the bone marrow. Preparations were obtained using conventional cytogenetic techniques. The results showed a) the role of the end points used as biomarkers in the early detection of genotoxic agents and in the identification of species and populations at higher risk; b) the difference in sensitivity of the species selected as bioindicators in relation to the cytogenetic end points analyzed; c) the need to use at least two sympatric species to detect the presence of genotoxins in each locality; and d) the need to use several end points when trying to establish a genotoxic profile of an area.

Enviromental genotoxicity evaluation: Bayesian approach for a mixture statistical model

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The data analyzed in this paper are part of the results described in Bueno et al (2000). Three cytogenetics endpoints were analyzed in three populations of a species of wild rodent -Akodon montensis -living in an industrial, an agricultural, and a preservation area at the Itajaí Valley, State of Santa Catarina, Brazil.

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“…The mixing distributions are beta densities. The statistical analyzes are under the bayesian perspective, as opposed to the frequentist ones often considered in the literature, as for instance in Bueno et al (2000). …”

“…The first situation is easily obtained in the laboratory, whereas, when collecting data from exposed individuals in the field, the second situation prevails. The latter is the case analyzed in a real situation of environmental exposure reported in Bueno et al (2000). In the present paper the data receive an alternative statistical treatment using mixtures of distributions and a Bayesian approach.…”

“…In the present paper the data receive an alternative statistical treatment using mixtures of distributions and a Bayesian approach. In Bueno et al (2000), the chance of a cell being damaged (probability of failure) is considered the same for each individual within a certain experimental group. Hence, independent Binomial (positive or negative) models with the same probability of failure were considered.…”

Pequenos mamíferos não-voadores do Planalto Atlântico de São Paulo: identificação, história natural e ameaças

“…Ao longo de sua distribuição ocupa diversas áreas alteradas, como campos não cultivados, campos cobertos por gramíneas, plantações de eucalipto, diversas plantações, área industrial, e campo antropogênico (Fonseca e Kierulff 1989, Lessa et al 1999, Bueno et al 2000, Lima 2000, Bonvicino et al 2002, Gheller-Costa 2002 (Pardini 2004). Além disso, em matas secundárias, prefere microhabitats mais jovens a mais maduros (Puttker et al 2008, Lima et al 2010.…”