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Classical theories of how animals make mate choices have focused on each sex's inherited preferences for the other sex's traits or behaviours. The present thesis was undertaken to investigate how social factors play a role in determining an animal's choice of mate. In the series of experiments reported here, 'focal' female and male Japanese quail were given the opportunity to observe another quail (a 'model') of the same sex mating with a conspecific of the opposite sex (a 'target'). Results of experiments described in chapters 2 and 3 revealed that focal females: (1) displayed an increased tendency to affiliate with male targets that they had observed mating with model females, and (2) found a target male more attractive if he had been observed just standing near another female. In Chapter 4, social influences or male mate choice were investigated. Focal males: (1) exhibited a decrease in their preference for female targets that they had observed mating with model males, and (2) showed a decrease in preference for a female target only if she had been seen mating with or being courted by a model male, not simply standing near him. Finally, in chapter 5, it was determined that for quail of both sexes, affiliation time was a reliable predictor of focal subjects' actual choice of a mate. Taken together, these results are consistent with the hypothesis that females gain benefits from attending to the mate choices of other females, whereas for males there is a cost associated with mating with a female that had recently muted with another male. / Thesis / Doctor of Philosophy (PhD)

Understanding how appetite is regulated, via exogenous or endogenous factors, is essential to animal agriculture in order to maximize production capabilities, as well as in human medicine to generate ways to treat conditions such as eating disorders or obesity. The aim of this thesis was to evaluate the effects of ferulic acid (FA), an exogenous factor found within plant cells, and oxyntomodulin (OXM), an endogenous hormone generated in the gastrointestinal tract, on food intake in avian models, as well as elucidate the hypothalamic mechanisms responsible. In broiler chicks (Gallus gallus), FA administered peripherally (IP) resulted in a transient yet potent reduction of food intake. A behavior analysis revealed that FA-treated chicks defecated fewer times than control birds. Within the arcuate nucleus (ARC) there was an increase in c-Fos immunoreactivity, indicating neuronal activation, in FA-treated chicks. Within the hypothalamus, there was a decrease in mRNA abundance of galanin, ghrelin, melanocortin receptor 3, and pro-opiomelanocortin (POMC), however within the ARC there was a decrease in POMC and an increase in c-Fos mRNA after FA treatment. OXM, a proglucagon-derived peptide produced in the gastrointestinal tract, administered intracerebroventricularly (ICV) or IP in Japanese quail (Coturnix japonica), resulted in a decrease in food intake for 3 hours post-injection. There was an increase in c-Fos immunoreactivity within the ARC as well as the dorsomedial nucleus (DMN) in quail ICV injected with OXM. In conclusion, these novel data provide insights on the similarities and differences between factors that can affect appetite regulation via anorexigenic effects. / Master of Science / Exogenous and endogenous factors affect appetite regulation. Exogenous factors originate in feed components, additives, and other environmental factors that can affect bodily functions but are derived from an external source. Endogenous factors are made within the body, such as hormones and neurotransmitters, usually in response to a stimulus, and serve to communicate signals both locally and distantly in the body. Ferulic acid (FA), a natural exogenous factor originating within plant cells, is found in commonly consumed plant-based foods. When administered peripherally into broiler chicks (meat-type birds), FA caused a direct and potent, yet quickly diminishing, decrease in food intake via activation of cells within the hypothalamus, the region of the brain that is responsible for appetite regulation. Oxyntomodulin (OXM), an endogenous peptide hormone generated within the gastrointestinal tract in response to the digestion of nutrients, is known to decrease food intake in humans, rodents, and the broiler chick. However, its effects in Japanese quail, a model closer to a "wild-type" bird, are unknown. Quail injected peripherally (outside the brain) or intracerebroventricularly (ICV; into lateral ventricle of brain) with OXM showed a reduction in food intake that was more persistent than FA's effects with the effects also mediated via activation within the hypothalamus, although through slightly different molecular mechanisms. Understanding different factors that can regulate appetite in animals is necessary for agricultural applications to maximize production and improve health and welfare, as well as in humans to elucidate methods to treat appetite-related conditions, such as eating disorders and obesity.

Polychlorinated biphenyls (PCBs) decrease thyroid function in rats and mice by inducing activity of a liver enzyme, uridine diphosphate-glucuronosyltransferase (UDP-GT), thereby increasing thyroxine (T4) clearance. This loss of T4 can lead to hypothyroidism. In this study, an assay was validated for measuring UDP-GT activity toward T4 in Japanese quail (Coturnix japonica). Then UDP-GT induction by Aroclor 1254 was evaluated in quail, and quail and mice were compared in their responses to Aroclor 1254. In Experiment 1, Japanese quail and Balb/c mice were dosed orally with vehicle or Aroclor 1254 (250 or 500 mg/kg) and sacrificed five days later. In Experiment 2, Japanese quail were dosed orally with vehicle or Aroclor 1254 (500 mg/kg) and sacrificed either five or 21 days later. Total liver UDP-GT capacity increased with Aroclor 1254 exposure in all treatment groups of both species. Enzyme induction led to a trend to decreased plasma T4 concentrations at both doses and exposure times in quail and significantly decreased plasma T4 concentrations at both doses in mice. PCBs altered thyroid function in quail, but they did not become hypothyroid. This was in contrast to mice, which did become hypothyroid. It is unclear how PCBs affect the hypothalamic-pituitary-thyroid (HPT) axis in quail, and activation of the HPT axis appears to be inhibited in mice. Overall, quail showed a lesser response than mice to equivalent doses of Aroclor 1254, so it appears that birds may be less vulnerable to PCBs than mammals. / Master of Science

Day 14 embryos (16.5-17 day incubation period) and 1 day old chicks of Japanese quail (Coturnix japonica) were used to study the effects of different egg iodine (I) availabilities on thyroid function during development. Low (≤50 μgI/kg feed in the maternal diet) and high (1200 μgl/kg feed) I availability were compared to control levels (800 μgI/kg feed). Thyroid gland (TG) content of I, triiodothyronine (T3), and thyroxine (T4), plasma concentrations of T3 and T4, and hepatic 5’ monodeiodinase (5’-D) activity was measured, and the response of the TG to thyrotropin (TSH) stimulation [TG-cAMP content and plasma thyroid hormone (TH) concentrations]. Also, the developmental patterns of TH concentrations in the TG and plasma were determined. With increased I availability, TG-I content is elevated but thyroidal T4 and T3 and the developmental pattern of TG-TH were not different from controls. Plasma T3 and T4 and the developmental pattern of plasma TH were not altered. Indicators of the TG response to TSH stimulation were not different with increased I availability. Hepatic 5’-D activity did not differ between control and high I availability. Reduced body weight was associated with increased I availability. In general, TG weight was not altered, but a small percentage of the high I birds exhibited TG hypertrophy and altered TG function. With low I availability, TG-I content was reduced. Although thyroidal T4 content was reduced on embryonic day 14 and thereafter, TG-T3 was maintained throughout development. The magnitude of the TG response to TSH stimulation was not altered with reduced I availability. Hepatic 5’-D activity, plasma TH concentrations and the developmental patterns of plasma TH were not different between control and low I availability. Reduced I availability did not affect body or TG weight. Developing Japanese quail exhibit excellent ability to adjust thyroid function over a wide range of I availabilities. Regulation appears to occur at TH synthesis which allows most aspects of thyroid dynamics to remain unchanged in the maintenance of circulating TH concentrations. / Master of Science

The investigation reported here involved an analysis of some of the biological factors affecting tonic immobility in young Japanese quail. Both duration and incidence of tonic immobility were measured on each bird at six days and again at 12 days of age. A significant line effect was found at both ages, and rankings of these lines for duration and incidence followed a similar pattern. Number of inductions and duration of immobility were inversely related, while the percentage incidence was positively associated with duration of immobility. A large maternal effect found at six days of age disappeared by 12 days of age. Additive genic effects were low to moderate which is indicative that tonic immobility is associated with fitness. / Master of Science

Using reverse-triiodothyronine, rT3, as substrate, an in vitro 5'deiodinase (5'0) assay was validated for adult Japanese quail, by defining conditions under which activity is proportional to enzyme (protein) concentration and is linear with incubation time. Activity was measured as the release of 1(125) from labeled rT3. Using validated assay conditions we found the following 5'0 characteristics: maximal activity from 10-50 mM dithiothreitol (cofactor), an apparent Km of 0.52 µM rT3, pH optimum of 7.6-8.5, complete inhibition by 1 mM propylthiouracil and by 1 mM iopanoic acid, and substrate affinities of rT3 > T 4> T3 . Based on these characteristics, the quail hepatic 5'0 activity is like the Type I 5'0 activity found in mammalian liver and kidney, and embryonic chicken liver. To determine how previous unvalidated assays, that used high tissue concentrations and relatively low substrate (T",) concentrations, influenced 5'0 studies we reevaluated 5'0 development using our assay validated for each developmental stage. We found extreme quantitative differences in the activities measured and in the proportional relationships among stages; and only limited qualitative Similarity existed in the pattern of 5'0 development when compared to unvalidated T4 assays. These data show good correspondence between whole liver 5'0 activity per unit body weight and plasma T3/T ... ratios for the developmental stages sampled. / Master of Science

Energy homeostasis is essential for survival across all vertebrate species and involves a multitude of physiological systems that are regulated by both central and peripheral neural signaling. The hypothalamus is responsible for integrating and processing these signals and thus is regarded as the regulatory center for balancing energy homeostasis. Eating disorders, such as compulsive eating behavior associated with obesity, and anorexia, are significant public health concerns worldwide. Thus, studying appetite regulation is necessary to provide novel information for the design of solutions for health concerns that stem from altered energy intake. Such information is also relevant for improving chicken health and productivity in an agricultural setting. The objective of this dissertation research was to determine the hypothalamic mechanisms underlying appetite regulation in birds. In Experiment 1, the Virginia lines of chickens were used to elucidate the mechanisms underlying stress-induced anorexia. These chickens have been selected for low (LWS) or high (HWS) body weight at 56 days of age and have different severities of anorexia and obesity, respectively. Chicks were subjected to a combination of thermal and nutritional stress after hatch and hypothalamic nuclei, including the lateral hypothalamus (LH), paraventricular nucleus (PVN), ventromedial hypothalamus (VMH), and arcuate nucleus (ARC), were collected 5 days later. Real-time PCR was used to measure the mRNA abundance of appetite-associated neuropeptides and receptors in each nucleus. The results showed that the two lines displayed distinct gene expression profiles in response to stress. In particular, the PVN of the LWS was significantly affected by stress, and expression of several anorexigenic factors was up-regulated including corticotropin-releasing factor (CRF), CRF receptor sub-types 1 and 2 (CRFR1 and CRFR2, respectively), melanocortin receptor 4, and urocortin 3, suggesting that stress-induced anorexia in the LWS may result from overriding anorexigenic signaling in the PVN, primarily through CRF signaling. This CRF signaling-associated hypothesis was further supported by results showing that the original phenotypes were restored when the LWS chicks were treated with astressin (CRF receptor antagonist) before exposure to stress. In Experiments 2 and 3, we attempted to determine the mechanisms of CRF's anorexigenic effect in chickens and Japanese quail. We administered CRF by intracerebroventricular (ICV) injection and the hypothalamus was collected 1 hour later for molecular analyses. Results showed that CRF exerted a similar inhibitory effect on food intake in these two bird species, however the hypothalamic mechanisms underlying this anorexigenic effect were different. ICV injection of CRF increased c-Fos expression in the PVN, VMH, dorsomedial nucleus (DMN), and ARC in chicks while it only affected the PVN and LH in quail. Hypothalamic gene expression results suggested that CRF decreased neuropeptide Y receptor sub-type 1 (NPYR1) in chicks while it increased proopiomelanocortin (POMC), MC4R, CRF, and CRFR2 in quail. These results suggested that the anorexigenic effect of CRF may involve a dampened neuropeptide Y (NPY) system in chicks whereas it is associated with activated CRF and melanocortin systems in quail. At the nucleus level in chicks, CRF injection decreased NPY system-associated gene expression (ARC and DMN) and increased CRF (ARC and PVN) and mesotocin (MT) (VMH)-associated mRNAs, suggesting that orexigenic signaling through NPY was overridden by the heightened anorexigenic tone through CRF and MT, which led to the inhibition of food intake. In Experiments 4 and 5, we used the same experimental design as for CRF studies to determine the hypothalamic mechanisms of the anorexigenic effects of neuropeptide K (NPK) and adrenomedullin (AM) in Japanese quail. Results from Experiment 4 showed that NPK injection activated the ARC and PVN, which was associated with increased mRNAs for a group of anorexigenic factors including CRF, UCN3, cocaine and amphetamine-regulated transcript (CART), and POMC, and decreased expression of several orexigenic factors, such as NPY and agouti-related peptide (AgRP). In Experiment 5, ICV injection of AM activated the ARC, the nucleus in which POMC and CART mRNAs were increased. In conclusion, these experiments revealed novel hypothalamic mechanisms underlying stress or exogenous neuropeptide-induced anorexia in birds and may provide insights on understanding appetite regulation from evolutionary, agricultural, and biomedical perspectives. / Ph. D. / Appetite regulation is important for survival across all vertebrate species and the hypothalamus is the regulatory center for control of feeding behavior. Thus, studying the functions of the hypothalamus on appetite regulation provide novel insight into the eating disorders, such as obesity and anorexia, a worldwide health issue. Also, such information is relevant for improving productivity in the modern chicken industry. The objective of this dissertation research was to determine the hypothalamic mechanisms underlying appetite regulation in birds. In Experiment 1, the Virginia lines of chickens were used to elucidate the mechanisms underlying stress-induced anorexia. These chickens have been selected for low (LWS) or high (HWS) body weight at 56 days of age and have different severities of anorexia and obesity, respectively. Chicks were subjected to a combination of thermal and nutritional stress after hatch. The results suggested the two lines displayed distinct appetite-associated gene expression profiles in response to stress in the hypothalamus. In particular, stress-induced anorexia in the LWS may result from potent feeding-inhibitory factor corticotropin-releasing factor (CRF). Thus, in Experiments 2 and 3, we attempted to determine the mechanisms of CRF's inhibitory effect on food intake in chickens and Japanese quail. We administered CRF by intracerebroventricular (ICV) injection and the hypothalamus was collected 1 hour later for molecular analyses. Results showed that CRF exerted a similar inhibitory effect on food intake in these two bird species. However, the inhibitory effect of CRF was primarily associated with a dampened neuropeptide Y (NPY) system which is a potent stimulatory factor for feeding behavior in chickens, whereas it may involve activated CRF and melanocortin systems in quail. In Experiments 4 and 5, we used the same experimental design as for CRF studies to determine the hypothalamic mechanisms of the inhibitory effects of neuropeptide K (NPK) and adrenomedullin (AM) in Japanese quail. Results from Experiment 4 showed that the feeding-inhibitory effect of NPK was associated with a group of increased feeding-inhibitory factors such as CRF and cocaine and amphetamine-regulated transcript (CART) and decreased feeding-stimulatory factors, such as NPY and agouti-related peptide (AgRP) in the hypothalamus. In Experiment 5, AM increased gene expression of CART and proopiomelanocortin (POMC). Overall, these experiments suggested the roles of the hypothalamus in stress or exogenous neuropeptide-induced anorexia in birds and may provide insights on understanding appetite regulation from evolutionary, agricultural, and biomedical perspectives.

Thesis (Ph.D.)--James Madison University, 2010. / Includes bibliographical references.

Soybean oil (SBO), menhaden fish oil (FO), chicken fat (CF) or hydrogenated soybean oil (HSBO) were incorporated at 5% of the total diet to study changes in the immunological status of both Japanese quail (JAP) and Bobwhite quail (BOB). The SBO diet, in which 66% of the total fatty acids were polyunsaturated fatty acids (PUFA), was rich in linoleic acid (LA 18:2 n-6), alpha-linolenic acid (ALA 18:3 n-3) and low in saturated fatty acid (SFA). The FO diet which contained about 50% PUFA, had only 40% n-6 fatty acids and 8% n-3 PUFA. The trans fatty acid isomers and other monounsaturated fatty acids (MUFA) were high in the HSBO diet. The diet containing CF provided a relatively balanced fatty acid composition with 18% SFA, 31% MUFA and 50% PUFA. Plasma fatty acid and hepatic fatty acid profiles consistently reflected their respective dietary lipid treatments. There were no differences in the fatty acid profile between blood and liver within respective dietary treatments in the two species. Dietary fatty acids had no effect on antibody titers against sheep red blood cells (SRBC) at 1, 2 and 8 months following the start of dietary lipid treatment in JAP. However, female JAP fed FO had a significantly (p< 0.05) higher antibody production compared to the other dietary lipid treatments at 4 months following the start of fatty acids supplementation. BOB fed either FO or SBO diets had a higher immunoglobulin G production compared to birds fed the CF diet. The total antibody titer was significantly higher in BOB fed SBO compared to CF. Dietary fatty acids had a significant effect on cell-mediated immunity (CMI) as accessed by toe web thickness 24 hours post intradermal injection of phytohemagglutinin-P (PHA) in both JAP and BOB. In general, birds fed a FO diet had a significantly higher CMI response than those fed HSBO. A diet high in n-3 PUFA increased the index of cutaneous basophil hypersensitivity (CBH), while the high trans fatty acid isomers suppressed the CBH response. By observing a CBH response over a 72-hour period in JAP, it was concluded that quail fed CF or SBO had a different peak response time (12 hours post PHA challenge) and amplitude compared with those fed FO or HSBO (24 hours post PHA challenge). Phagocytic ability was not affected by dietary lipid treatments in BOB while the quail fed FO diet had a faster carbon clearance rate. The FO fed JAP had a significantly higher response (p< 0.05) to concanavalin A ensiformis (CONA) compared to HSBO fed birds. There was no difference in B lymphocyte proliferation stimulated by lipopolysacchride (LPS) in female JAP, whereas it was significantly higher in male JAP fed SBO compared to those fed FO and HSBO. Phorbol 12-myristate 13-acetate/ionomycin calcium salt (PMA/ION) was used to nonspecifically stimulate cell proliferation by increasing chromosome mitosis. Dietary FO or HSBO suppressed cell proliferation stimulated by PMA/ION. However, JAP fed SBO or CF had a significantly higher PMA/ION stimulated lymphocyte proliferation compared those fed FO or HSBO. In male BOB, the FO fed birds had the highest response to all mitogens. In contrast, female BOB did not show any dietary effects by lymphocyte proliferation. Consistent with JAP, BOB fed HSBO had depressed lymphocytes proliferation in response to various mitogens stimulation. In general, female birds had a higher plasma total protein (PTP) and lower pack cell volume (PCV) compared to their males counterparts in both BOB and JAP. In summary, in in vivo experiments, feeding a diet high in menhaden fish oil that is rich in n-3 PUFA enhanced the CMI. There was a minimal effect on antibody production caused by feeding n-3 PUFA in JAP since a significant treatment effect was only found at one sampling period, while BOB were more sensitive to dietary lipid manipulation and had a higher antibody production with SBO or FO treatments. Dietary lipids exerted different effects in the two species in in vitro experiments. While both BOB and JAP fed FO had higher lymphocyte proliferation to CON A mitogen compared to those fed HSBO, only male BOB showed a higher proliferation to LPS. Feeding HSBO that contained a higher content of trans fatty acid isomers, MUFA, but lower PUFA content resulted in the lowest lymphocyte proliferation to various mitogens in both BOB and JAP. / Ph. D.