Mitochondrial biogenesis-associated factors underlie the magnitude of response to aerobic endurance training in rats.

Trainability is important in elite sport and in recreational physical activity, and the wide range for response to training is largely dependent on genotype. In this study, we compare a newly developed rat model system selectively bred for low and high gain in running distance from aerobic training to test whether genetic segregation for trainability associates with differences in factors associated with mitochondrial biogenesis. Low response trainer (LRT) and high response trainer (HRT) rats from generation 11 of artificial selection were trained five times a week, 30 min per day for 3 months at 70 % VO2max to study the mitochondrial molecular background of trainability. As expected, we found significant differential for the gain in running distance between LRT and HRT groups as a result of training. However, the changes in VO2max, COX-4, redox homeostasis associated markers (reactive oxygen species (ROS)), silent mating-type information regulation 2 homolog (SIRT1), NAD(+)/NADH ratio, proteasome (R2 subunit), and mitochondrial network related proteins such as mitochondrial fission protein 1 (Fis1) and mitochondrial fusion protein (Mfn1) suggest that these markers are not strongly involved in the differences in trainability between LRT and HRT. On the other hand, according to our results, we discovered that differences in basal activity of AMP-activated protein kinase alpha (AMPKα) and differential changes in aerobic exercise-induced responses of citrate synthase, carbonylated protein, peroxisome proliferator-activated receptor gamma coactivator-1α (PGC1-α), nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), and Lon protease limit trainability between these selected lines. From this, we conclude that mitochondrial biogenesis-associated factors adapt differently to aerobic exercise training in training sensitive and training resistant rats.

Aging and exercise affect the level of protein acetylation and SIRT1 activity in cerebellum of male rats.

Aging is associated with a gradual decline in cognitive and motor functions, the result of complex biochemical processes including pre- and posttranslational modifications of proteins. Sirtuins are NAD(+) dependent protein deacetylases. These enzymes modulate the aging process by lysine deacetylation, which alters the activity and stability of proteins. Exercise can increase mean life-span and improve quality of life. Data from our laboratories revealed that 4 weeks of treadmill running improves performance in the Morris Maze test for young (4 months, old) but not old (30 months, old) male rats, and the exercise could not prevent the age-associated loss in muscle strength assessed by a gripping test. The positive correlation between protein acetylation and the gripping test suggests that the age-dependent decrease in relative activity of SIRT1 in the cerebellum impairs motor function. Similarly to the acetylation level of total proteins, the acetylation of ά -tubulin is also increased with aging, while the effect of exercise training was not found to be significant. Moreover, the protein content of nicotinamide phosphoribosyltransferase, one of the key enzymes of NAD biosynthesis, decreased in the young exercise group. These data suggest that aging results in decreased specific activity of SIRT1 in cerebellum, which could lead to increased acetylation of protein residues, including ά-tubulin, that interfere with motor function.

Resurrection of the earthworm species Dendrobaena fedtschenkoi (Michaelsen, 1900), a former synonym of Dendrobaena byblica (Rosa, 1893) (Clitellata: Megadrili).

Dendrobaena byblica (Rosa, 1893) is a Circum-Mediterranean earthworm species complex containing more than a dozen synonymous names. From these, only two species have been resurrected so far, D. ganglbaueri (Rosa, 1894) and Fitzingeria annectens (Rosa, 1895). Here we demonstrate that Dendrobaena fedtschenkoi (Michaelsen, 1900) described from the Pamir Mts. Tajikistan differs from D. byblica both in morphological and molecular features, and represents an independent species.

Proper experimental design requires randomization/balancing of molecular ecology experiments.

Properly designed (randomized and/or balanced) experiments are standard in ecological research. Molecular methods are increasingly used in ecology, but studies generally do not report the detailed design of sample processing in the laboratory. This may strongly influence the interpretability of results if the laboratory procedures do not account for the confounding effects of unexpected laboratory events. We demonstrate this with a simple experiment where unexpected differences in laboratory processing of samples would have biased results if randomization in DNA extraction and PCR steps do not provide safeguards. We emphasize the need for proper experimental design and reporting of the laboratory phase of molecular ecology research to ensure the reliability and interpretability of results.

Accuracy, limitations and cost efficiency of eDNA-based community survey in tropical frogs.

Rapid environmental change in highly biodiverse tropical regions demands efficient biomonitoring programmes. While existing metrics of species diversity and community composition rely on encounter-based survey data, eDNA recently emerged as alternative approach. Costs and ecological value of eDNA-based methods have rarely been evaluated in tropical regions, where high species richness is accompanied by high functional diversity (e.g., the use of different microhabitats by different species and life stages). We first tested whether estimation of tropical frogs' community structure derived from eDNA data is compatible with expert field assessments. Next, we evaluated whether eDNA is a financially viable solution for biodiversity monitoring in tropical regions. We applied eDNA metabarcoding to investigate frog species occurrence in five ponds in the Chiquitano dry forest region in Bolivia and compared our data with a simultaneous visual and audio encounter survey (VAES). We found that taxon lists and community structure generated with eDNA and VAES correspond closely, and most deviations are attributable to different species' life histories. Cost efficiency of eDNA surveys was mostly influenced by the richness of local fauna and the number of surveyed sites: VAES may be less costly in low-diversity regions, but eDNA quickly becomes more cost-efficient in high-diversity regions with many sites sampled. The results highlight that eDNA is suitable for large-scale biodiversity surveys in high-diversity areas if life history is considered, and certain precautions in sampling, genetic analyses and data interpretation are taken. We anticipate that spatially extensive, standardized eDNA biodiversity surveys will quickly emerge in the future.

Surveying Europe's Only Cave-Dwelling Chordate Species (Proteus anguinus) Using Environmental DNA.

In surveillance of subterranean fauna, especially in the case of rare or elusive aquatic species, traditional techniques used for epigean species are often not feasible. We developed a non-invasive survey method based on environmental DNA (eDNA) to detect the presence of the red-listed cave-dwelling amphibian, Proteus anguinus, in the caves of the Dinaric Karst. We tested the method in fifteen caves in Croatia, from which the species was previously recorded or expected to occur. We successfully confirmed the presence of P. anguinus from ten caves and detected the species for the first time in five others. Using a hierarchical occupancy model we compared the availability and detection probability of eDNA of two water sampling methods, filtration and precipitation. The statistical analysis showed that both availability and detection probability depended on the method and estimates for both probabilities were higher using filter samples than for precipitation samples. Combining reliable field and laboratory methods with robust statistical modeling will give the best estimates of species occurrence.

The rate of training response to aerobic exercise affects brain function of rats.

There is an increasing volume of data connecting capacity to respond to exercise training with quality of life and aging. In this study, we used a rat model in which animals were selectively bred for low and high gain in running distance to test t whether genetic segregation for trainability is associated with brain function and signaling processes in the hippocampus. Rats selected for low response (LRT) and high response training (HRT) were randomly divided into control or exercise group that trained five times a week for 30 min per day for three months at 70% VO2max. All four groups had similar running distance before training. With training, HRT rats showed significantly greater increases in VO2max and running distance than LRT rats (p < 0.05). On the reverse Morris Maze test HRT-trained rats outperformed HRT control ones. Significant difference was noted between LRT and HRT groups in redox milieu as assessed by levels of reactive oxygen species (ROS), carbonylation of proteins, nNOS and S-nitroso-cysteine. Moreover the silent information regulator 1 (SIRT1), brain-derived neurotrophic factor (BDNF), ratio of phospho and total cAMP-response element binding protein (CREB), and apoptotic index, also showed significant differences between LRT and HRT groups. These findings suggest that aerobic training responses are not localized to skeletal muscle, but differently involve signaling processes in the brain of LRT and HRT rats.

Agreement and Diagnostic Performance of FITNESSGRAM®, International Obesity Task Force, and Hungarian National BMI Standards.

PURPOSE: This study examined agreement between all 3 standards (as well as relative diagnostic associations with metabolic syndrome) using a representative sample of youth from the Hungarian National Youth Fitness Study. METHOD: Body mass index (BMI) was assessed in a field sample of 2,352 adolescents (ages 10-18.5 years) and metabolic syndrome status was assessed in a laboratory subsample of 373 youth. All youth were categorized into weight status groups based on the FITNESSGRAM®, International Obesity Task Force (IOTF), and Hungarian growth standards. Classification agreement was compared between all pairs of standards via cross-tabulation. Logistic regression was used to estimate the odds of metabolic syndrome by weight status. RESULTS: The 3 BMI standards agreed on ≥  88% of cases, with better agreement on girls' standards than boys' standards. Kappa values ranged from .65 to .89. Using the Hungarian standards over the Fitnessgram or IOTF standards resulted in 5% to 10% more youth being classified as normal weight. The overweight/obesity groups were 4 times to 6 times more likely to have metabolic syndrome than those classified as normal weight regardless of the classification standards. These odds ratios increased to 8 times to 17 times when comparing the normal-weight/overweight groups to the obesity category. Odds ratios for boys tended to be slightly larger than those for girls. CONCLUSIONS: All 3 standards provide similar information about weight status and metabolic syndrome classification. To more easily facilitate international comparisons, it may be of greater benefit to use the IOTF standards, which also had better agreement with the U.S. Fitnessgram thresholds.

The effects of cocoa supplementation, caloric restriction, and regular exercise, on oxidative stress markers of brain and memory in the rat model.

The effects of treadmill running (8 weeks, 5 times/week, 1h/day at 27 m/min), caloric restriction, and cocoa supplementation on brain function and oxidative stress markers were tested. The Morris maze test was used to appraise rat memory. Regular exercise significantly improved spatial learning performance. The level of oxidative stress was measured by the concentration of carbonylated proteins. The free radical concentration increased in brain of the training groups but not the controls. The content of reactive carbonyl derivates did not change with exercise, suggesting that the increased production of reactive oxygen species (ROS) were well tolerated in this experimental model. Caloric restriction (CR) decreased the accumulation of free radicals in the frontal lobe. The protein content of brain-derived neutrophic factors (BDNFs) was evaluated and changes did not occur either with exercise or cocoa supplementation treatments. These data did not show significant effects of the administration of cocoa (2% w/w) on the concentration of ROS, BDNF or on spatial memory. Conversely, exercise and CR can play a role in ROS generation and brain function.