Background: Gene expression regulation is one of the fundamental mechanisms of phenotypic plasticity and is expected to respond to selection in conditions favoring phenotypic response. The observation that many organisms increase their stress tolerance after acclimation to moderate levels of stress is an example of plasticity which has been long hypothesized to be based on adaptive changes in gene expression. We report genome-wide patterns of gene expression in two heat-tolerant and two heat-sensitive parthenogenetic clones of the zooplankton crustacean Daphnia pulex exposed for three generations to either optimal (18°C) or substressful (28°C) temperature. Results: A large number of genes responded to temperature and many demonstrated a significant genotype-byenvironment (GxE) interaction. Among genes with a significant GxE there were approximately equally frequent instances of canalization, i.e. stronger plasticity in heat-sensitive than in heat-tolerant clones, and of enhancement of plasticity along the evolutionary vector toward heat tolerance. The strongest response observed is the across-the-board down-regulation of a variety of genes occurring in heat-tolerant, but not in heat-sensitive clones. This response is particularly obvious among genes involved in core metabolic pathways and those responsible for transcription, translation and DNA repair. Conclusions: The observed down-regulation of metabolism, consistent with previous findings in yeast and Drosophila, may reflect a general compensatory stress response. The associated down-regulation of DNA repair pathways potentially creates a trade-off between short-term benefits of survival at high temperature and long-term costs of accelerated mutation accumulation.

Poikilothermic organisms experience trade-offs associated with life at different temperatures caused by incompatible physiological and biochemical demands caused by temperature extremes. As the result many such organisms exhibit acclamatory effects, adjusting their metabolism and physiology to recently experiences temperatures. One such acclamatory effect is the metabolic compensation that allows an organism to withstand increases in temperature by decelerating biological rates below Arrhenius expectations, presumably reducing energetic demand and reducing stress. Daphnia magna is resilient across a wide temperature range, and if acclimated to mildly stressful temperatures first, exhibits longer survival in lethal temperatures. Certain genotypes of Daphnia also exhibit higher acute thermal tolerance than others, indicating the presence of genetic variation and local adaptation in heat tolerance. This study examined the effect of ambient temperature (5°C-37°C) and acclimation history (2 generations at 10°C or 25°C) on the oxygen consumption rates of 8 genotypes of Daphnia (4 with high acute temperature tolerance, and 4 low). There are nonlinear decelerations of Daphnia respiratory rates across a temperature gradient when acclimated to 25°C or following short 8-hour acclimation to measurement temperatures. Furthermore, Daphnia exposed to a near-lethal temperature (35°C) with a subsequent 24-hour recovery period at their native 25°C-acclimation temperature shows no indication of respiratory damage. Genotype showed no difference in metabolic compensation, indicating the process is genetically constrained. Regulation of mitochondrial and membrane function are promising areas to further characterize the mechanism of metabolic compensation found in this study.

Poikilothermic organisms experience trade-offs by differential physiological demands generated by temperature extremes. Many such organisms exhibit acclimatory effects, adjusting their metabolism and physiology to recently experienced temperatures. One such acclimatory effect is metabolic compensation, the deceleration of biological rates below Arrhenius expectations. Daphnia magna is eurythermal, and if acclimated to mildly stressful temperatures first, survives longer in lethal temperatures. This study examined the effect of ambient temperature (5°C-37°C) and acclimation history (lifetime at 10°C or 25°C) on the oxygen consumption rates of 8 genotypes of Daphnia with high or low acute temperature tolerance. There were decelerations of respiratory rates across a temperature gradient when acclimated to 25°C or following short 8- hour acclimation to measurement temperatures. Daphnia exposed to a near-lethal temperature (35°C) with a 24-hour recovery period at 25°C-acclimation temperature showed no difference in respiratory control compared to unexposed 25°C-acclimated Daphnia. Genotypes showed no difference in potential compensatory ability.

The diploma thesis is focused on the topic of adult diabetes type 1 and type 2 education related to patients' self-care management. It provides the elemental overview of the illness, its complications, treatment and wider social impact and anticipated future development; it presents the general theories, procedures and principles applied to the field of adult education and describes the specifics of diabetes patient education. As a follow-up to the theoretical part, an empirical survey is carried out to verify the connection between the education of diabetics and their metabolic compensation as a main indicator of diabetes-related quality of life. In addition, the differences in compensation between patients treated within diabetes center, regular diabetologists'offices and practising physians' offices are examined.