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The neuroendocrine basis of paternal behaviour is hypothesised to be homologous to that of maternal behaviour, with the expression of paternal behaviour resulting from the activation of estrogen-sensitive pathways in the brain. However, despite the fact that Phodopus campbelli fathers are highly paternal, previous studies have failed to identify an activational role for estradiol in the expression of this behaviour. The goal of this thesis was to exclude or define a role for estradiol in P. campbelli paternal behaviour. In the first study, estrogen receptor alpha (ERα) expression was examined in three brain regions relevant to maternal behaviour (medial preoptic area, bed nucleus of the stria terminalis, and medial amygdala). Male and female P. campbelli and its close relative P. sungorus were sampled as sexually naïve adults, following mating to satiety, or as new parents. As predicted, new fathers of either species did not upregulate ERα expression in these brain regions. Mating also had no effect on ERα expression in males or females from either species. However, ERα expression was also not upregulated in any of the three brain regions in new mothers. Thus, it is possible that estradiol does not play a primary role in activating maternal behaviour in Phodopus females. In the second study, P. campbelli males were administered the aromatase inhibitor letrozole at three different developmental stages (independence from the mother, testicular maturation, and sexually naïve adult) and tested for adult sexual and paternal behaviour. Aromatase inhibition during juvenile development resulted in diminished expression of adult paternal and sexual behaviour, suggesting that estradiol acts at critical periods in development to organize the paternal brain for subsequent behavioural responses. Treatment of sexually naïve adults did not alter male behaviour, which further supports previous evidence that estradiol does not activate paternal behaviour in P. campbelli males, although sexual behaviour in females is completely estradiol-dependent in this species. These findings suggest that the activational roles of estradiol in maternal and male sexual behaviour identified in the rat do not generalize to Phodopus, and imply greater species to species variation in the neuroendocrine control of these behaviours than previously suspected. / Thesis (Ph.D, Biology) -- Queen's University, 2008-09-15 10:52:00.161

As solitary animals, giant pandas (Ailuropoda melanoleuca) rely on chemical communication in order to determine reproductive condition of conspecifics. Therefore, we hypothesize certain biogenic volatile compounds affect mating behavior in giant pandas. Giant pandas housed at Memphis Zoo, Zoo Atlanta, San Diego Zoo, Edinburgh Zoo, and Toronto Zoo (n=5 males and n=5 females) were the subjects of this study. Urine, anatomical site, and environmental samples were collected during the breeding period (Feb-June) and non-breeding period (Aug-Dec) from 2012-2016. Volatile compounds in urine and the environment were extracted using solid phase micro-extraction (SPME), while compounds collected from various body sites of giant pandas were extracted with hexane. Compounds were analyzed and identified using gas chromatography mass spectrometry (GC-MS). Male behavioral trials consisted of a simultaneous choice test between days of the estrous cycle (e.g. proestrus, estrus, and metestrus) and pooled diestrus urine of unknown female giant pandas. The experimental period included eight 15-minute behavior trials over the course of 12 days. In addition, male giant pandas were exposed to isolated compounds found naturally in female urine during four 15-minute behavior trials over the course of 7 days. We predict that urine from a specific day of the peri-estrual period motivates sexual behaviors and physiological responses in males. Male physiological responses to female urine and specific chemical compounds were examined by changes in urinary androgen metabolites and the urinary volatile profile. By coupling male behavior responses and the female urinary chemical profile during the peri-estrual period, relevant compounds may be identified as possible pheromones related to estrus and mating behavior. To increase genetic viability of small populations, giant pandas require continued conservation and management aimed at facilitating communication and breeding across isolated populations. With low population numbers of giant pandas in the wild spread across fragmented habitats, a better knowledge of chemical communication in this species may provide vital information to improve the conservation and management of giant pandas.

Every organism needs to survive and successfully reproduce in the face of changing environmental conditions in which variation in resource availability can seriously limit performance. Organisms can respond to the variation in quality or availability of food resources with behavioural and physiological accommodations going from the baseline physiological response to environmental stressors to complex life-history strategies like migration and diapause. In insects, one avenue to cope with the resources’ variation is to plastically tune the reproductive system to the environmental conditions in order to shift resources away from reproduction during unfavourable periods but maximize it when resources are abundant. I studied the role of reproductive physiology in both males and females in mediating a response to challenging conditions determined by a lack of food resources or the presence of qualitatively different diets using the milkweed bug, Oncopeltus fasciatus, as model species. I studied the role of oosorption, a plastic physiological response through which resources can be recovered and redirected to body maintenance and survival, in shaping behavioural strategies to cope with challenging environments. I also studied the effects of diet quality on male’s sexual behaviour and how these modulate the trade-offs between reproduction and survival. I then investigated how the effects of diet quality, sexual maturation and rearing conditions influence the occurrence of reproductive diapause in both males and females. I found that females exposed to different diets plastically adapt their schedule of reproduction depending on diet quality: this also influences the occurrence of oosorption in the ovary mediating the amount of resources that are directed to reproduction or survival. Diet quality influences males’ sexual behaviour so that even after a long-term adaptation on an alternative artificial diet, they invest more in reproduction at the expenses of survival when fed on an ancestral high quality diet; this is achieved with a shift in the trade-off between reproduction and survival. The occurrence of reproductive diapause in both males and females is a function of several factors: the quality of food resources ultimately modulates sexual maturation in adult individuals determining the occurrence of diapause or reproduction. Finally, oosorption may be involved in the evolution of alternative condition-dependent strategies as an adaptive physiological mechanism to cope with stressful environments; thus females from different populations may be able either to migrate in favourable areas where they can exploit abundant food resources or remain residents and perform high levels of oosorption to cope with the seasonal shortage of food.

abstract: For animals that experience annual cycles of gonad development, the seasonal timing (phenology) of gonad growth is a major adaptation to local environmental conditions. To optimally time seasonal gonad growth, animals use environmental cues that forecast future conditions. The availability of food is one such environmental cue. Although the importance of food availability has been appreciated for decades, the physiological mechanisms underlying the modulation of seasonal gonad growth by this environmental factor remain poorly understood. Urbanization is characterized by profound environmental changes, and urban animals must adjust to an environment vastly different from that of their non-urban conspecifics. Evidence suggests that birds adjust to urban areas by advancing the timing of seasonal breeding and gonad development, compared to their non-urban conspecifics. A leading hypothesis to account for this phenomenon is that food availability is elevated in urban areas, which improves the energetic status of urban birds and enables them to initiate gonad development earlier than their non-urban conspecifics. However, this hypothesis remains largely untested. My dissertation dovetailed comparative studies and experimental approaches conducted in field and captive settings to examine the physiological mechanisms by which food availability modulates gonad growth and to investigate whether elevated food availability in urban areas advances the phenology of gonad growth in urban birds. My captive study demonstrated that energetic status modulates reproductive hormone secretion, but not gonad growth. By contrast, free-ranging urban and non-urban birds did not differ in energetic status or plasma levels of reproductive hormones either in years in which urban birds had advanced phenology of gonad growth or in a year that had no habitat-related disparity in seasonal gonad growth. Therefore, my dissertation provides no support for the hypothesis that urban birds begin seasonal gonad growth because they are in better energetic status and increase the secretion of reproductive hormones earlier than non-urban birds. My studies do suggest, however, that the phenology of key food items and the endocrine responsiveness of the reproductive system may contribute to habitat-related disparities in the phenology of gonad growth. / Dissertation/Thesis / Doctoral Dissertation Biology 2014

Visuals play an important role in the healthcare field; students learning anatomy and physiology, patient education materials, and public infographics all rely on the effective communication of textual material in graphic form. The goal of this thesis is to contribute visual material that takes the form of signaling pathways and comparison of different disorder states as material for use in the university setting. In order to produce reliable visuals, a literature review was completed.

A grande maioria das espécies de anfíbios anuros apresenta um padrão de reprodução sazonal, caracterizado nos machos por um pico de andrógenos que desencadeia maturação testicular, bem como manutenção do comportamento sexual. No entanto, os altos níveis de andrógenos podem apresentar um efeito imunossupressor, podendo também aumentar a probabilidade de infecções parasitárias. A Caatinga brasileira é caracterizada por altas temperaturas e chuvas sazonais e imprevisíveis que determinam o padrão reprodutivo e de atividade dos anuros dessa região, algumas espécies como P. diplolister apresentam comportamento de estivação durante a seca, já Rhinella Jimi e R. granulosa permanecem ativos quanto ao forrageamento durante este período. As drásticas variações deste ambiente poderiam acentuar os ajustes fisiológicos apresentados por essas espécies, principalmente para a espécie estivadora. Foram estudadas as inter-relações entre caracteres morfológicos, fisiológicos e parasitológicos dessas três espécies de anuros, em três períodos distintos, (A) durante a temporada reprodutiva, em um período entre dois surtos reprodutivos (período entre chuvas); (B) durante um surto reprodutivo que acompanhou um evento de chuvas e (C) no período da seca. As duas espécies de Rhinella apresentaram evidências de modulações imunológicas de acordo com período, e correlações entre caracteres imunológicos, fisiológicos e número de parasitas. Pleurodema diplolister apresentou padrões imunológicos coerentes com o processo de economia energética durante a estivação, como redução do número de leucócitos totais, com concomitante aumento na contagem de eosinófilos e relação positiva entre intensidade parasitária e contagem total de leucócitos. As três espécies estudadas apresentaram depleção das reservas energéticas durante o período reprodutivo, possivelmente associada à alta demanda energética do comportamento vocal. Também apresentaram padrões similares de maturação testicular, evidenciando que as espécies estudadas possuem um padrão de reprodução oportunista, típico de espécies que ocupam ambientes áridos. As três espécies também apresentaram relação entre parâmetros imunológicos e carga parasitária, no entanto, para esclarecer as relações causais entre esses fatores, são necessários testes adicionais de desafio imunológico, bem como infecção experimental por parasitas / Most part of anurans show a seasonal pattern of reproduction, when males display high levels of androgens associated with testicular development and sexual behavior maintenance. However, high androgens levels also can shows an immunosuppressive effect resulting in increased parasitological disease. The semi-arid Caatinga is an environment characterized by high temperatures and unpredictable seasonal rains that determine the breeding season of anurans. During the dry season, Pleurodema diplolister aestivate borrowed, Rhinella granulose and R. jimi remain foraging. Drastic variation in this environment could increase the physiological adjustments displayed by these species, mainly by P. diplolister. The inter-relation between morphological, physiological and parasitological characters was studied in these three anuran species, in three different periods: (A) dry season, (B) during the rainfall, when males are calling, and (C) in the interval between rainfalls, when males are foraging within the reproductive season. The Rhinella species presented evidences of immunological modulations according to the period and correlations between immunological, physiological parameters and number of parasites. Pleurodema diplolister presented immunological patters consistent with the process of energy economy during aestivation, including total leukocyte reduction, along with eosinophil increase and positive relation between total leukocyte and parasite intensity. The three species presented depletion in energy reserves during the breeding season, possibly associated with the high energy demand of vocal behavior. They also presented a similar pattern of testicular development, indicating that these species present opportunistic reproduction pattern, typical of species that occupy arid environments. The studied species also showed correlations between immunological parameters and parasite load, however, to clarify the causal relation between these parameters, additional immunological challenges and experimental parasite infection are necessary