In this study, we evaluated the development of stress response in (1) two different species of quail, one species that is relatively fast-growing (Japanese quail, Coturnix japonica) and one that is relatively slow-growing (Gambel’s quail, Callipepla gambelii) and (2) two strains of a single species, the Japanese quail (wild-type and domesticated), that differ considerably in final size. Our data indicate that wild-type Japanese quail and Gambel’s quail have experienced trade-offs between growth and the stress response (e.g. Gambel’s quail have slower growth rates, but greater levels of CORT). However, the domesticated strain of Japanese quail used in this study seem to violate some predictions based on the life history theory (e.g. the domestic strain has faster growth rates and greater levels of CORT). The data in this study contribute to the understanding of differences in the stress response between species that exhibit different life history strategies.

Cyprodinil and pyraclostrobin are widely used pesticides to protect many plants from attack of microorganisms and fungal diseases. Although cyprodinil and pyraclostrobin exist in the aquatic environment at low concentration, their leftovers in the ecosystems lead to oxidative damage and interfere development in aquatic animals at environmental-relevant concentration. To figure out the combined effect of cyprodinil and pyraclostrobin, mortality and morphology were investigated in zebrafish embryos exposed to 0.1 and 1μM of cyprodinil, pyraclostobin, and their mixture. Also, gene expression profiles were investigated following exposure to both the compounds and their mixture. Mortality and morphology data showed that the mixture is extremely toxic to zebrafish embryos as it increased mortality in concentration-dependent manner and interfered development of zebrafish embryos at 72 hpf. For gene expression analysis, 0.01μM of cyprodinil, pyraclostobin, and their mixture were used. A total of 47 genes were analyzed. Genes involved in apoptosis, cell cycle arrest, DNA damage repair, drug metabolism, stress response, immune response, and lipid metabolism and transport were analyzed. Upregulation of bax for pyraclostrobin suggests that this chemical could induce mitochondrial apoptotic pathway in zebrafish embryos at 144 hpf. Upregulation of cyp1a for cyprodinil indicates that it could produce ROS and cause oxidative damage in zebrafish embryos. Altered expression of several genes for mix suggests that the mixture of cyprodinil and pyraclostrobin have inhibitory effect on gene expression. Overall, the present study suggests that the mixture of cyprodinil and pyraclostrobin could delay of zebrafish embryonic development, increase mortality of zebrafish embryos, and regulate the expression of several genes.

The Domestication Syndrome Hypothesis posits that domesticated animal species exhibit a shared set of traits encompassing behavioral, physiological, and morphological characteristics. While this hypothesis has garnered significant attention, the evidence supporting its universality remains limited, particularly in species such as dogs and cattle. In this dissertation, I examined the Domestication Syndrome Hypothesis in mixed breed pet and shelter dogs as well as Holstein dairy heifers. This investigation focused on behavioral responses, physiological reactivity, and Domestication Syndrome Hypothesis-associated morphological variables in relation to human interaction. First, I explored the behavioral responses of Holstein dairy heifers representing a range of white spotting phenotypes towards people and handling, and their physiological response towards handling during an industry-standard palpation procedure. Additionally, I explored three pigmentation variables (coat color/pattern, eumelanin pigmentation, and white spotting) in dogs residing in a known stressful environment, an animal shelter. I assessed their baseline in-shelter cortisol and their cortisol response to an intervention in which they left the shelter to spend time with people. Lastly, I investigated citizen science behavioral surveys of owned mixed breed dogs to determine potential correlations between white spotting or ear set and various behavioral factors, including human sociability and aggression. Altogether, I found partial support for the Domestication Syndrome Hypothesis: some results aligned with the expectations of the Domestication Syndrome Hypothesis and some did not. Notably, in Holstein dairy heifers, I observed that less white spotting predicted a greater increase in cortisol levels and a higher rate of stepping in response to palpation, results that support the premises of the Domestication Syndrome Hypothesis. Moreover, in owned mixed breed pet dogs, I found that human sociability positively correlated with white spotting and floppier ears and that decreased arousal, decreased aggression, and increased proximity-seeking correlated with floppier ears, further supporting the Hypothesis. However, many of the correlations predicted by the Hypothesis were not statistically significant or exhibited an opposite direction to what was expected. For instance, more extensive white spotting in Holsteins predicted a higher rate of vocalization during palpation, pigmentation did not significantly predict cortisol levels in shelter dogs, and in owned mixed breed dogs playfulness and biddability negatively correlated with white spotting while biddability negatively correlated with floppier ears. Prior research on the Domestication Syndrome Hypothesis in dogs did not find covariation between domestication-associated behavioral and morphological traits, which the researchers suggest may have been driven by modern breeding practices; this confound could have also impacted my studies. Together, the results – both supportive and contradictory – included in this dissertation contribute to our understanding of the Domestication Syndrome Hypothesis. Further research is needed to reconcile these inconsistencies and explore the underlying mechanisms behind the observed relationships. By expanding sample sizes, using more standardized study designs, and investigating causative mechanisms, future studies can enhance our knowledge of the Domestication Syndrome Hypothesis and its implications in the domestication process of animals. / Doctor of Philosophy / The Domestication Syndrome Hypothesis suggests that domesticated animals share common traits in their behavior, physiology, and physical appearance. However, the evidence supporting this idea is limited, especially in dogs and cattle. In this dissertation, I studied mixed breed pet and shelter dogs, as well as Holstein dairy heifers, to explore the Domestication Syndrome Hypothesis. I looked at how these animals behaved and how their stress hormone levels changed when interacting with humans. For the dairy heifers, I focused on their responses to being handled during a routine procedure called a palpation. In dogs, I examined three aspects of their physical appearance related to the hypothesis: coat color/pattern, the color of their noses, and how much white fur they had. I also assessed their stress hormone levels while in the shelter and when they had a chance to spend time with people outside the shelter. Additionally, I collected information from surveys of mixed breed dogs owned by the public to see if their appearance was linked to their behavior. Altogether, my findings partially support the Domestication Syndrome Hypothesis: some results matched the expectations of the Domestication Syndrome Hypothesis and some did not. For example, I found that Holstein heifers with more black fur had higher stress hormone levels and moved their feet more when palpated, which aligns with the Hypothesis. Additionally, pet dogs with floppier ears were more sociable with people and less prone to aggression and dogs with more white fur were more sociable with people, such also supports the Hypothesis. However, some of the results did not support the Hypothesis. For example, heifers with more white fur vocalized more during palpation and pigmentation did not predict stress hormone levels in shelter dogs. Also, pet dogs with more white fur were less playful and obedient and dogs with more floppy ears were less obedient. Recent research on the Domestication Syndrome Hypothesis in dogs did not find a connection between how dogs behave and look. This might have been due to recent changes to why dogs are bred, which also could have influenced my results. Both the supportive and conflicting results help us to better understand the Domestication Syndrome Hypothesis. Additional research studying more animals, using more consistent evaluations, and asking why these traits seem to be linked can further deepen our understanding of the Domestication Syndrome Hypothesis and its relevance to animal domestication.

Mutations in mitochondrial aminoacyl-tRNA synthetases (mtARSs) have been reported in patients with mitochondriopathies: most commonly encephalopathy, but also cardiomyopathy. Through a GWAS, we showed possible associations between mitochondrial valyl-tRNA synthetase (VARS2) dysregulations and non-ischemic cardiomyopathy. We aimed to investigate the possible consequences of VARS2 depletion in zebrafish and cultured HEK293A cells. Transient VARS2 loss-offunction was induced in zebrafish embryos using Morpholinos. The enzymatic activity of VARS2 was measured in VARS2-depleted cells via northern blot. Heterozygous VARS2 knockout was established in HEK293A cells using CRISPR/Cas9 technology. BN-PAGE and SDS-PAGE were used to investigate electron transport chain (ETC) complexes, and the oxygen consumption rate and extracellular acidification rate were measured using a Seahorse XFe96 Analyzer. The activation of the integrated stress response (ISR) and possible disruptions in mitochondrial fatty acid oxidation (FAO) were explored using RT-qPCR and western blot. Zebrafish embryos with transient VARS2 loss-of-function showed features of heart failure as well as indications of CNS and skeletal muscle involvements. The enzymatic activity of VARS2 was significantly reduced in VARS2-depleted cells. Heterozygous VARS2-knockout cells showed a rearrangement of ETC complexes in favor of complexes III2, III2 + IV, and supercomplexes without significant respiratory chain deficiencies. These cells also showed the enhanced activation of the ISR, as indicated by increased eIF-2 phosphorylation and a significant increase in the transcript levels of ATF4, ATF5, and DDIT3 (CHOP), as well as disruptions in FAO. The activation of the ISR and disruptions in mitochondrial FAO may underlie the adaptive changes in VARS2-depleted cells.

Previous research discovered the existence of sedimentation-resistant mutants of E. coli. Genomic studies revealed that these mutants resisted sedimentation due to independent modifications to genes that influenced the Rcs signal transduction pathway, causing increased secretion of an exopolysaccharide capsule comprised primarily of colanic acid. The Rcs system is responsible for detecting envelope stressors; consequently, ampicillin and osmotic stress were used to perturb the cellular envelope and study the response of the mutants compared to wild-type cells. It was found that the overproduction of colanic acid in the mutants confers some resistance to envelope stress; however, the mutants still behaved similarly to wild-type cells. The doubling times of the strains grown in sodium chloride solutions were calculated. A wavelength scan from 400 nm to 800 nm was performed on strains grown in different salt concentrations to determine if there were significant differences in light scattering between the wild-type and mutant cells. Further analysis was performed that, along with the doubling time data, suggested that wild-type cells may have turned on genes for capsule production in response to being grown in high salt concentrations. Additional research could be conducted to test this hypothesis, perhaps through the quantification of colanic acid through a methyl pentose assay for wild-type cultures grown with high salt concentrations. The idea that wild-type cells could digest colanic acid as a carbon source when lacking resources was also investigated with different preparations of colanic acid. One preparation of colanic acid showed promising results, which could indicate that bacteria are able to digest their capsule in a novel method to produce energy when starved. Again, additional investigation should be conducted to confirm these results. Other future experiments could study the metabolome of these mutants to determine if they have increased quantities of alarmones related to biofilm formation.

Abiotic stresses cause extensive loss to agriculture production worldwide. Cowpea is an important legume crop grown widely in tropical and subtropical regions where high temperature, ultraviolet-B (UVB) radiation and drought are the common stress factors limiting production. Various vegetative, physiological, biochemical and reproductive plant attributes were assessed under a range of UVB radiation levels in Experiment I and in a combination with two doses of each carbon dioxide concentration [CO2], temperature, and UVB radiation and their interactions in Experiment II by using six cowpea genotypes and sunlit plant growth chambers. The dynamics of photosynthesis and fluorescence processes were assessed in 15 cowpea genotypes under drought condition in Experiment III in pot-grown plants under sunlit conditions. A distinct response pattern was not observed in cowpea in response to UVB radiation form 0 to 15 kJ; however, plants grown under elevated UVB showed reduced photosynthesis resulting in shorter plants and produced smaller flowers and lower seed yield. Increased phenolic compounds appeared to be a defense response to UVB radiation. The growth enhancements observed by doubling of [CO2] were not observed when plants were grown in combination with elevated UVB or temperature which also showed the most detrimental effects on plant growth and seed yield. Results form Experiment I and II revealed that cowpea reproductive traits were highly sensitive to abiotic stresses compared to the vegetative growth and development. A total stress response index (TSRI) technique, derived from all vegetative and reproductive parameters, was used to screen genotypes for their stress tolerance to UVB or combination of stresses. An increase in water use efficiency while maintaining higher rate of photosynthesis was an important drought tolerance mechanism in tolerant cowpea genotypes. Using principal component analysis technique, four groups of the genotypes were identified for their drought tolerance. Evaluating same genotypes across stress conditions revealed that no single genotype has the absolute tolerance characters to all stress conditions. The identified diversity for abiotic stress tolerance among cowpea genotypes and associated traits can be used to develop tolerant genotypes suitable for an agro-ecological niche though traditional breeding or genetic engineering methods.

No description available.

No description available.

No description available.

No description available.