Bisphenol A (BPA) is used for the production of plastics and epoxy resins, which are part of packaging materials for food and beverages, and can migrate into food and the environment, thus exposing human beings to its effects. Exposure to BPA has been associated with oxidative stress, cell cycle changes, and genotoxicity, and is mediated by its known endocrine-disrupting activity. Possible BPA cytotoxicity without mediation by estrogen receptors has been reported in the literature. Here, we show the toxic effects of BPA by live-cell imaging on the fission yeast Schizosaccharomyces pombe, an experimental model lacking estrogen receptors, which were in line with data from flow cytometry on intracellular oxidation (76.4 ± 14.4 and 19.4 ± 16.1% of fluorescent cells for BPA treatment and control, respectively; p < 0.05) as well as delay in cell cycle progression (after 90 min of experiment, 48.4 ± 4.30 and 64.6 ± 5.46% of cells with a 4C DNA content for BPA treatment and control, respectively; p < 0.05) upon exposure to BPA. These results strongly support the possibilities that BPA-induced cell cycle changes can be independent of estrogen receptors and that live-cell imaging is a powerful tool for genotoxic analysis.

As future scientists, university students need to learn how to avoid making errors in their own manuscripts, as well as how to identify flaws in papers published by their peers. Here we describe a novel approach on how to promote students' ability to critically evaluate scientific articles. The exercise is based on instructing teams of students to write intentionally flawed manuscripts describing the results of simple experiments. The teams are supervised by instructors advising the students during manuscript writing, choosing the 'appropriate' errors, monitoring the identification of errors made by the other team and evaluating the strength of their arguments in support of the identified errors. We have compared the effectiveness of the method with a journal club-type seminar. Based on the results of our assessment we propose that the described seminar may effectively complement the existing approaches to teach critical scientific thinking.

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