Environmental factors are known to have far reaching effects on nervous system function, and in the adult brain, it is clear that a wide range of environmental stimuli modulate cell proliferation and survival (e.g., neurogenesis). This project investigated whether social stimulation and concomitant changes in gonadal hormones can influence the proliferation of new cells in the adult brain. The adult green treefrog (Hyla cinerea)was used as the model system; studying the courtship behavior of the highly social treefrog affords a direct, quantifiable way to measure the effects of acoustic social cues and hormonal intervention on adult brain cell proliferation. Using immunohistochemistry techiques, endocrinological manipulations, and socially-relevant acoustic stimulus presentations, I report that social cues modulate cell proliferation in the brains of adult male and female H. cinerea. I first mapped the distribution of proliferative areas in the adult treefrog brain using 5-bromo-2′- deoxyuridine (BrdU) labeling. I then exposed naturally-cycling male and female treefrogs to random tones or a recording of a natural H. cinerea chorus for ten days during the breeding season. I found that male and female treefrogs that heard their conspecific chorus exhibited increased brain cell proliferation compared to animals that heard random tones. Moreover, this modulation was region-specific and occurred in those regions which reflected their presumed involvement in reproductive physiology and behavior: the preoptic area (POA) and the infundibular hypothalamus (IF). To determine the involvement of gonadal hormones in cell proliferation with and without social stimulation, I gonadectomized and implanted male and female H. cinerea with blank or steroid-filled implants. After exposing the treefrogs to the same acoustic conditions as above, I discovered that social modulation of adult cell proliferation can occur without the influence of gonadal hormones (i.e., androgens in the male and estrogen in the female). Furthermore, the results revealed that neither hormone was neurotrophic and in fact, chronically-elevated estrogen levels decreased cell proliferation in the female POA and IF. Together, these results indicate that the reception of acoustic social cues increases cell proliferation in brain regions mediating sexual behavior and endocrine regulation; furthermore, this modulation occurs in a sexually-differentiated fashion without gonadal hormone influence. / text

In this thesis the need for nutrients for rabbits was described. Anthocyanins were described as biological substances contained in wheat with non-traditional coloring and their possible antioxidant effects. The second part of the review is devoted to bio-chemical parameters of animal blood. The practical part was aimed at the study of the influence of feed mixture with increased content of anthocyanins. In the experiment, a wheat species PS Karkulka with purple pericarp was used and Vanessa was used as control wheat species. Both of these made 15% of the feed diet. 18 rabbit females of which 9 were in the experimental group and 9 in the control group were included in the experiment. They were fed a complete pelleted mixture. In the experiment, the weight of the animals, the average weight gains, the feed consump-tion, the feed conversion ratio were monitored. After slaughter, slaughter yield, bio-chemical blood analysis and antioxidant activity were monitored. The results show that the differences in average live weight were statistically in-significant, only at week 8 the differences in live weight was statistically significantly higher in the control group. Average weight gains were evaluated as statistically insig-nificant. Statistically significantly higher average feed consumption was found in the control group. The carcass weight was significantly higher in the control group. There were no statistically significant differences in biochemical parameters and blood anti-xodation activity.

The thesis compares the structure of feed mixture and the feed residues after the feeding broilers rabbits Hyla. There were made two different feed mixtures – the control one and the experimental one. The experimental feed mixture contained 10 % of purple grain wheat called PS Karkulka. In the control one was used 10 % of wheat Vanessa with classical colour of grain. The feed mixtures and the feed residues were separated on different wide sieves to find the size share. Than the feed mixture and the feed residues were compared. The quantity of parts bigger than 2 mm in the feed residues decreased and the quantity of parts smaller than 2 mm increased. Both with statistical significance (P<0.05). To detect the taste preferences between PS Karkulka and Vanessa the parts bigger than 2 mm in both types of feed residues were separated to individual components and compared. There was found that rabbits preferred the colored grained wheat (PS Karkulka) more than the classical one (Vanessa) with statistical significance (P<0.05). The next part is about performance parameters. The weight gain, carcass weight, carcass yield, feed consumption and feed conversation ratio were evaluated. In all of that parameters there were not found statistically significant differences (P˃0.05) between control group and experimental group.

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Anthropogenic disturbances can alter the abiotic composition of freshwater systems. These compositional changes can act as physiological stressors towards system inhabitants. However, little is known about how these altered abiotic factors influence stress hormones (corticosterone) in larval amphibians. Throughout the following chapters, I examined the effects of several abiotic factors on baseline and stress-induced corticosterone levels in the larvae of four amphibian species: Jefferson salamander (Ambystoma jeffersonianum), spotted salamander (A. maculatum), wood frog (Rana sylvatica), and grey treefrog (Hyla versicolor). Chapter II examined corticosterone level differences throughout development in A. jeffersonianum and R. sylvatica larvae under field, mesocosm, and laboratory venues. Baseline corticosterone levels in R. sylvatica increased near metamorphic climax in all venues, but not in A. jeffersonianum. Rather, baseline corticosterone levels differed with respect to venue throughout development in A. jeffersonianum. Chapter III examined corticosterone level differences among free-living A. jeffersonianum populations and possible abiotic factors underlying these hormone differences. Corticosterone levels significantly differed across populations. Increased baseline corticosterone levels significantly correlated to low pH. There was also a trend for increased baseline corticosterone levels to be positively correlated with chloride levels and negatively correlated with conductivity. Chapter IV examined the effects of laboratory manipulated pH on corticosterone levels in A. jeffersonianum, A. maculatum, R. sylvatica, and H. versicolor. There was a significant correlation between increased baseline corticosterone levels to low pH in all four species. Prey consumption (in both Ambystoma species) and survival (in A. jeffersonianum, A. maculatum, and R. sylvatica) were also negatively correlated to low pH. Chapter V examined the effects of increased conductivity on corticosterone levels in A. jeffersonianum, R. sylvatica, and H. versicolor. Increased conductivity exposure significantly correlated to increased baseline corticosterone levels in A. jeffersonianum and R. sylvatica. Prey consumption in A. jeffersonianum was also negatively correlated to increased conductivity. My dissertation shows that abiotic factors, such as pH and conductivity, can influence corticosterone levels in larval amphibians. These results suggest that corticosterone levels in larval amphibians may be a suitable biomarker reflective of altered freshwater habitat quality. However, my results also suggest that one should use a high degree of caution when using corticosterone levels in larval amphibians as a means to infer the health status of a population. / Ph. D.

Ce travail s’intègre dans le cadre du programme européen COMET (7ième PCRD EURATOM) et vise à évaluer les réponses épigénétiques (particulièrement la méthylation de l’ADN), lors d’expositions chroniques à de faibles niveaux de substances radioactives.Lors d’une première expérience, les poissons zèbres (Danio rerio) ont été exposés au laboratoire à des concentrations environnementales d’uranium appauvri : 2 et 20 µg L-1. Cette expérimentation a révélé un impact sur la méthylation de l’ADN génomique, majoritairement chez les mâles exposés, croissant avec la durée et le niveau d’exposition. Lors d’une seconde expérience, nous avons observé un impact sur les profils de méthylation de la descendance issue de parents exposés, ainsi qu’une perturbation du statut transcriptomique et des dommages histologiques dans le muscle squelettique des larves issues de parents exposés.Les outils développés ont pu être appliqués à la problématique d’étude des effets biologiques induits par les radionucléides émis lors de l’accident de la centrale nucléaire de Fukushima Daiichi. Les analyses réalisées sur la grenouille arboricole Japonaise (Hyla japonica) ont révélé une corrélation positive entre la dose totale de radioactivité absorbée par ces grenouilles, l’hyperméthylation de l’ADN génomique et l’augmentation des dommages à l’ADN mitochondrial.L’ensemble de ces travaux a permis de mettre en évidence la sensibilité des réponses épigénétiques chez différents organismes soumis à de faibles doses de radionucléides, qui pourraient ainsi permettre de mieux caractériser les mécanismes d’adaptation et les potentiels effets transgénérationnels induits par les radionucléides. / This work integrates within the general framework of the European program COMET (7th Framework Programme EURATOM) and aims to assess the epigenetic responses (particularly DNA methylation), during chronic exposure to low levels of radioactive materials. During a first experiment, zebrafish (Danio rerio) were exposed in laboratory controlled conditions to environmentally relevant concentrations of depleted uranium: 2 and 20 µg L-1. This experiment allowed an impact on the genomic DNA methylation to be demonstrated, mainly in exposed males, which increased with the duration and level of exposure. In a second experiment, we observed an impact on DNA methylation patterns in the progeny of exposed parents, as well as a perturbation of transcriptomic, and histological damage in larvae skeletal muscle from exposed parents.The methods developed were applied to the second context focusing on the study of biological effects induced by radionuclides emitted following the Fukushima Daiichi nuclear power plant accident. The analyses performed on the Japanese tree frog (Hyla japonica) revealed a positive correlation between the total dose of radiation absorbed by these frogs, hypermethylation of genomic DNA as well as increasing damage to mitochondrial DNA.This work highlighted the sensitivity of epigenetic responses in different biological models exposed to low levels of radionuclides, and could be used to further characterize adaptation mechanisms and potential transgenerational effects induced by radionuclides.

Fire may alter both aquatic and terrestrial habitat used by all amphibian life stages, yet, our knowledge of its effects on amphibians is primarily limited to adult responses. I present an integrated approach to test the response of Cope’s Gray Treefrog (Hyla chrysoscelis) to fire by examining responses in tadpole performance and survivorship, adult abundance, and oviposition. Tadpoles raised with burned leaf litter had similar survival, but total mass and total length were 440% and 170% greater, respectively, for tadpoles raised in unburned litter. I assessed terrestrial and aquatic oviposition cues by embedding burned and unburned litter treatments within burned and unburned terrestrial plots. Oviposition was an order of magnitude higher in unburned plots, regardless of the litter treatment. This difference was not statistically significant or driven by adult abundance. My results indicate the need to explore the dynamic effects forest management practices can have on amphibians across life stages.

The successful completion of this work is dedicated first to my grandparents for having always shown their unwavering love and encouragement in my journeys (most of which they kindly and politely only pretended to understand) and for having also served as life-long role models who upheld an unparalleled work ethic. To many whom I consider to be my chosen family, especially Ann Williams and Brittany Sears, who kept me laughing, but more importantly, kept my crazy train from derailing during these tumultuous years. To Wayne Price and Tom Jackman, who fostered the success of my career and are the epitome of patience and kindness. To DeAngelis, for the many hours of laughter, conversations, and adventuresome treks that further kindled my knowledge, love, and respect for Florida’s ecology. To family in Alabama who have either helped shape my brazen character or made this education possible. To Taego, the one to whom I am bound through so many of the stories that begin with, “Remember when…?” and who is often so kind and thoughtful though he still holds tightly to the stereotype of the selfish youngest sibling. Finally, to Fen for being my smiling, bright blue-eyed, spunky kid who has been on this journey with me from the get-go; for keeping me from getting too big for my britches; for your intrinsic fire that burns for equality, fairness, and friendship; and for inspiring me to be the best example of a mother that I can possibly be.

Males of European tree frog are clustered in the chorus in order to attract females. Males were re-captured, their body size and position in chorus was recorded. Goal of this thesis was investigated a correlation between the males' body size and mating behaviour and their position in the chorus.

The work deals with the influence of the Milk thistle (used substance Silymarin) on the carcass yield of hybrid combinations rabbits Hyla. Hybrid combination Hyla was purposefully bred for meat performance, showing excellent results in breeding. Rabbits behave primarily on meat, because nutritional properties correspond to the current requirements of rational nutrition. Therefore, it is appropriate to increase the carcass yield. The average slaughter yield is indicated from 40 to 53% according to the breed. It was found that the addition of milk thistle in the form of a powder in the complete feedingstuff at a concentration of 0.2% increased the carcass yield, relative to the control group (which was fed only KKS), on average by 0.4%. The group with the addition of 1% showed an average value of 1.2% higher than the group control. The average slaughter yield of all the groups ranged from 54,68 into 63,02%. In both farms also decreased the incidence of diarrheal disease. Silymarin has a favorable effect on the operation and growth of the liver. In the group with the addition of 0.2% increased the average liver weight of 8.1 g, in the group with a concentration of 1% weight on average picked up about 10g. The average weight of the liver varied from 111,19 to 121,20 g. The control group in the case of carcass yield and liver weight showed better results than the authors of their articles.