Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and non-reproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17α-ethinylestradiol (EE2) on anxiety, shoaling behavior and fertility in zebrafish after developmental treatment and remediation in clean water until adulthood. Zebrafish embryos were exposed from day 1 to day 80 post fertilization to actual concentrations of 1.2 and 1.6ng/L EE2. After remediation for 82days non-reproductive behavior and fertilization success were analyzed in both sexes. Males and females from the 1.2ng/L group, as well as control males and females, were bred, and behavior of the untreated F1 offspring was tested as adults. Developmental treatment with 1.2 and 1.6ng/L EE2 significantly increased anxiety in the novel tank test and increased shoaling intensity in both sexes. Fertilization success was significantly reduced by EE2 in both sexes when mated with untreated fish of opposite sex. Progeny of fish treated with 1.2ng/L EE2 showed increased anxiety in the novel tank test and increased light avoidance in the scototaxis test compared to control offspring. In conclusion, developmental exposure of zebrafish to low doses of EE2 resulted in persistent changes in behavior and fertility. The behavior of unexposed progeny was affected by their parents' exposure, which might suggest transgenerational effects.
Blood volume is the most important variable for the detection of microorganisms in blood cultures (BCs). Most standards recommend 40 to 60 ml blood, collected in several BC bottles filled up to 10 ml. We measured blood volume in individual BC bottles and analyzed the associations of hospital, bottle type, day of the week, daily sampling time, and age and sex of the patient with sampling volume and BC result. The variation in blood volume per BC bottle was analyzed in a mixed linear model using hospital, bottle type, weekday, sampling time, age, and sex as fixed factors and patient identification (ID) and episode as random factors to control for repetitive sampling of individual patients. Only 18% of all bottles were filled with the recommended 8 to 10 ml, and 47% were filled with less than 8 ml. The mean (± standard error) volume was larger in positive bottles (9.09 ± 0.15) than in negative bottles (8.47 ± 0.07) (P < 0.001). Blood volume was larger in BacT/Alert-FA Plus bottles than in -FN Plus BC bottles (P < 0.001). There were significantly lower volumes collected during the night (P < 0.001). The volume of blood collected decreased significantly with increasing patient age (P < 0.001). Larger volumes were collected from male patients than from female patients: 8.78 (± 0.06) versus 8.36 (± 0.06) ml (mean ± standard error [SE]), respectively (P < 0.001). The odds of detecting a positive patient increases by 13% for each additional milliliter of blood drawn. Our results show that we need to work actively with the development of blood sampling routines to overcome age and sex effects and to optimize blood sampling volumes.
We made a reciprocal transplantation experiment with Carlina vulgaris, among 12 seminatural grassland sites situated in southwest Sweden. The fate of seeds and seedlings were followed during 2 years. Local adaptation was investigated both by native superiority over non-natives, and by comparing the observed performance of a population to the fitted value of a reduced statistical model that showed the populations' performance at all sites and the performance of all other populations at its home site. The latter method indicates presence of local adaptation even when natives are inferior to introduced populations as long as the negative difference in fitness between the populations is smaller at the native population's home site. The strength of local adaptation was measured as the ratio of the observed to the expected performance in reduced statistical models and regressed on the degree of isolation and population size. We found no evidence of local adaptation in terms of native superiority compared to non-natives, but with the relative method we found one of six fitness components, juvenile survival, to be 6% higher for natives at their home sites compared to how they performed at other sites and how others performed at their site. Further, our results indicate that both isolation and population size have a positive effect on the process of local adaptation.
Sewage effluents contain pharmaceuticals, personal care products and industrial chemicals, exposing aquatic organisms to complex mixtures. The consequences of exposure to combinations of different classes of drugs in fish are largely unknown. In this study, we exposed adult zebrafish (Danio rerio) males and females for two weeks to low, environmentally relevant concentrations of the endocrine disrupting chemical 17α-etinylestradiol (EE) and the selective serotonin re-uptake inhibitor (SSRI) citalopram, alone and in combination, and analyzed behaviors of importance for population fitness, scototaxis (light/dark preference), the novel tank test and shoal cohesion. Control water contained 0.4ng/L EE and the measured exposure concentrations were 0.9ng/L EE (nominal 0.1) and 1ng/L EE (nominal 0.5). The measured concentrations of citalopram were 0.1 (nominal 0.1) and 0.4μg/L (nominal 0.5). Both EE exposures increased anxiety in males in the scototaxis test, with significantly longer latency periods before entering and fewer visits to the white zone of the tank. The combined exposures (0.9ng/L EE+0.1μg/L citalopram and 1ng/L EE+0.4μg/L citalopram) resulted in abolishment of effects of EE, with shorter latency period and more transitions to white than for fish exposed to EE alone. In the novel tank test, the results surprisingly indicated lower anxiety after both EE and citalopram exposure. Significantly more transitions to the upper half of the tank observed in males exposed to 0.1μg/L citalopram alone compared to control males. Males exposed to EE (0.9ng/L) had shorter latency period to the upper half. Combination exposure resulted in a longer latency and fewer transitions to the upper half compared to both control, EE- and citalopram-exposed males. Males exposed to the combination spent significantly less time in the upper half than males EE or citalopram-exposed males. Females exposed to 1ng/L EE had fewer transitions to the upper half than the control group and females exposed to 0.4μg/L citalopram. In the shoaling test, males exposed to 0.1μg/L citalopram+0.9ng/L EE showed more transitions away from peers than males exposed to 0.1μg/L citalopram alone. In conclusion, low concentrations of EE, closely above the predicted no effect concentration (NOEC) of 0.1ng/L, created anxiety-like behavior in zebrafish males. Citalopram showed marginal effects at these low concentrations but in the combination exposure the behavioral effects of EE were abolished. This is an initial effort to understand the effects of cocktails of anthropogenic substances contaminating aquatic environments.
Size, allocation of biomass, seed production of hermaphrodites and male steriles as well as germination, growth rate and survival among their progeny were compared between male fertile and male sterile cytoplasmic genotypes of Plantago maritima. The cytoplasmic genomes in angiosperms are predominantly maternally inherited. Thus we used the progeny originating from the male fertile and male sterile mothers in order to examine the relative success of the mothers. The progeny was grown together at three different densities in a greenhouse competition experiment. The results were analysed in a hierarchical model with siblings as replicates of mothers and mothers as replicates of sex-morphs. Differences between sex morphs were very small, but they were consistent in that the progeny from male steriles always performed less well than did the progeny from hermaphrodites. Male sterile progeny matched the hermaphrodite progeny best at the lowest density, where there was no effect of sex type on the level of individual performance. One explanation why hermaphrodites perform relatively better at higher densities could be that they are more plastic in their response to competition induced stress. This was indicated by density dependent allocation pattern of biomass to different parts of the plants, where the progeny of hermaphrodites appeared to be more plastic. The results from this experiment, and other studies, supports the idea that male sterility, if nucleo-cytoplasmically determined, can persist in a population even without any fitness advantages for females.
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