H2AX phosphorylation screen of cells from radiosensitive cancer patients reveals a novel DNA double-strand break repair cellular phenotype

BACKGROUND: About 1-5% of cancer patients suffer from significant normal tissue reactions as a result of radiotherapy (RT). It is not possible at this time to predict how most patients' normal tissues will respond to RT. DNA repair dysfunction is implicated in sensitivity to RT particularly in genes that mediate the repair of DNA double-strand breaks (DSBs). Phosphorylation of histone H2AX (phosphorylated molecules are known as gammaH2AX) occurs rapidly in response to DNA DSBs, and, among its other roles, contributes to repair protein recruitment to these damaged sites. Mammalian cell lines have also been crucial in facilitating the successful cloning of many DNA DSB repair genes; yet, very few mutant cell lines exist for non-syndromic clinical radiosensitivity (RS).\ud \ud METHODS: Here, we survey DNA DSB induction and repair in whole cells from RS patients, as revealed by gammaH2AX foci assays, as potential predictive markers of clinical radiation response.\ud \ud RESULTS: With one exception, both DNA focus induction and repair in cell lines from RS patients were comparable with controls. Using gammaH2AX foci assays, we identified a RS cancer patient cell line with a novel ionising radiation-induced DNA DSB repair defect; these data were confirmed by an independent DNA DSB repair assay.\ud \ud CONCLUSION: gammaH2AX focus measurement has limited scope as a pre-RT predictive assay in lymphoblast cell lines from RT patients; however, the assay can successfully identify novel DNA DSB repair-defective patient cell lines, thus potentially facilitating the discovery of novel constitutional contributions to clinical RS

Data for: Assortative mating in an ecological context: Effects of mate choice errors and relative species abundance on the frequency and asymmetry of hybridization

The frequency and asymmetry of mixed-species mating set the initial stage for the ecological and evolutionary implications of hybridization. How such patterns of mixed-species mating, in turn, are influenced by the combination of mate choice errors and relative species abundance remain largely unknown. We develop a mathematical model that generates predictions for how relative species abundances and mate choice errors affect hybridization patterns. When mate choice errors are small (<5%) the highest frequency of hybridization occurs when one of the hybridizing species is at low abundance, but when mate choice errors are high (>5%) the highest hybridization frequency occurs when species occur in equal proportions. Furthermore, females of the less abundant species are overrepresented in mixed-species matings. We compare our theoretical predictions with empirical data on naturally hybridizing Ficedula flycatchers and find that hybridization is highest when the two species occur in equal abundance, implying rather high mate choice errors. We discuss ecological and evolutionary implications of our findings and encourage future work on hybrid zone dynamics that take demographic aspects, such as relative species abundance, into account

Gaining momentum: Popularization of Epilobium angustifolium as food and recreational tea on the Eastern edge of Europe

The local use of wild food plants represents a reservoir for the biocultural diversity of human diet and is therefore being extensively studied; yet the effects of the introduction of novel uses into specific biocultural conditions have been little researched. Rosebay willowherb Epilobium angustifolium L. has been intensively promoted in Europe since the mid-18th century. The expert recommendations did not provide any links to local uses thus raising the question of the legitimacy and diffusion of its food use in modern times. To understand if and to what extent those recommendations have influenced local uses, we compared them with the results of our ethnobotanical field study and the ethnographic literature in Russia, Finland, Estonia, Latvia, Lithuania, Belarus and Ukraine. Of the 599 people interviewed, nine used E. angustifolium as a food and 59 as a recreational tea. Thirty-four of those who claimed to use E. angustifolium lived in two regions of Russia. The majority of the recorded tea uses were of recent origin, following a popular trend. Few food uses of E. angustifolium were recorded in Finland, where a trend towards culinary experimentation coincides with a general trend toward the consumption of healthy wild food; yet these uses are difficult to maintain due to the problems in recognizing the plant during its early stages of growth. The popularization of E. angustifolium as a food had more effect in times of hardship, when it was seen as a means of survival and its promotion was advocated. The translation error repeatedly appeared in botanical and later popular literature, whose authors did not clearly differentiate at that time between local uses and suggestions