Haruka Wada, Ph.D. - US grants

On every set of genes in every individual (the genotype), the environment exerts its influence to shape observable traits (or phenotypes); this is phenotypic plasticity. Recently, the field of phenotypic plasticity has been split into two subfields: the first is a focus for evolutionary biologists whose goal is to understand how phenotypic plasticity evolved over time, and the other is a focus for physiologists whose goal is to identify the physiological mechanisms underlying the gene-environment interaction. This symposium has three goals aimed at bridging these two subfields. First, the meeting will bring together researchers from the two subfields who otherwise do not cross paths to discuss how their respective theoretical framework can be tested experimentally and how empirical data from one group can give insights to the other. This will help advance our understanding of the costs, benefits, and limitations of phenotypic plasticity and to identify future direction of this field. The second goal is to foster interaction and future collaboration between researchers from the two subfields to bring new approaches and define new directions. The third goal is to encourage participation from early career scientists (e.g., undergraduate and graduate students and postdoctoral researchers) and scientists from underrepresented groups to provide them with an opportunity to receive feedback from senior scientists and identify future mentors. The sequence of talks, alternating between evolutionary biologists and physiologists, and inclusion of designated time for questions and discussion are designed to further cross-disciplinary interactions. Abstracts from all the talks and posters will be publicly available, and papers from the symposium talks will be published in the Integrative and Comparative Biology journal to ensure the dissemination of the symposium.

Stressful events can permanently modify how an organism functions. Those same conditions in adults can also be traced back to events early in life. Therefore understanding how organisms respond to environmental stress is crucial. However, this has been challenging partly because although responses to stress have been studied at but the cellular and whole organism level, scientists have not yet made a successful link between stress to the whole animal and the cellular consequences. The goals of the project are to 1) improve our understanding of stress responses at both levels and 2) critically evaluate how the stress response is regulated. This project also aims to improve science literacy and inquiry-based science education in rural regions of Alabama. First, this project will contribute to a more holistic view of how organisms respond to stress, and will teach middle and high-school students how events at molecular and whole-animal levels are interconnected. Second, models describing stress response regulation have been applied to evaluate diseases risk factors, e.g., obesity and socioeconomic status. This project will educate Alabamian public school students about the consequences of obesity, lifestyle, and diet and how to overcome stress. Finally, the participation in, and quality of, science fair projects in southeastern Alabama has been extremely low, although such projects provide a great opportunity to implement an inquiry-based approach to science education. In collaboration with biology teachers, the project will provide training, mentorship, and opportunities to conduct science fair projects to spark interests in biology, inspire scientific careers, and increase science literacy in regions historically underserved in STEM education.

Conceptualizing and studying stress has been challenging because stress responses extend across multiple biological scales, and the consequences of stress are often non-linear. This lack of integration is a major obstacle in this field, and is well exemplified by glucocorticoid- and heat shock protein-focused studies of stress responses. Therefore, this project will characterize an integrative stress response involving both HSPs and glucocorticoids. Specifically, this project will test the hypothesis that HSPs and glucocorticoids prime each other's response in preparation for subsequent stressors by determining whether 1) glucocorticoids elevate HSP and associated transcription factor and 2) a disruption in proteostasis, as regulated by the heat shock response pathway, elicits glucocorticoid responses. Elevation of HSPs and glucocorticoids has both protective and damaging effects. The allostasis model conceptualizes this non-linear nature of stress, yet this model has not been explicitly tested. Using zebra finches which adjust their heat tolerance with prior heat-conditioning, the project will also evaluate the allostasis model by testing the hypothesis that pre-conditioned birds elicit greater HSP and glucocorticoid responses than birds with no prior exposure to the stressor, thereby protecting individuals from stress-related suppression of reproductive and immune functions. By defining the direct and reciprocal relationship between HSP and glucocorticoid responses, this project will characterize organismal orchestration of the HSP response and provide a molecular basis for the switch from protective to damaging effects of glucocorticoids. Furthermore, this project will provide an in-depth evaluation of the allostasis model and whether this model applies to a stressor beyond nutritional stress.

Most organisms respond to environmental and social stressors by a stress response. However, knowledge of how the stress response is integrated across levels of organization from molecules, to cells, to the whole organism remains limited. This symposium will bring together biologists across levels of organization and at different career stages to gain a richer insight into how organisms respond to stress. During the symposium, speakers from different levels of organization will alternate with one another. Immediately following the symposium, a structured round table discussion will be hosted aimed at identifying key outstanding questions in stress biology and integrative approaches that can be used to study the stress responses of animals, including domesticated and rare species, across levels of organization. There will also be complimentary oral and poster sessions geared towards early career scientists from diverse backgrounds to increase the potential for idea exchange and collaborations between scientists at different career stages and that traditionally study the stress response at different levels of analyses.

Most organisms initiate a highly conserved stress response in the face of environmental and social stressors. Yet, information about how the stress response is integrated across levels of biological organization from genomes to phenomes is incomplete. However, it is becoming increasingly clear that a comprehensive understanding of the evolution of the stress response will require integrative studies that span levels of analyses. This information will be critical for predicting how selection will influence the expression of this complex phenotype at the organismal level, as well as how the integration of the underlying mechanisms will influence the evolutionary response to selection. As diverse organisms are expected to experience rising stress exposure in the face of anthropogenic disturbance and rapidly changing environments, this knowledge is becoming increasingly urgent.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

How organisms respond to a stressful situation varies greatly among individuals and partly depends on prior experience with the stressor. This variation makes predictions of how an individual or population of individuals will endure stressful events extremely difficult. Historically, studies on stress focused on stress responses rather than the consequences of variation in responses. Using a comparative approach with individual birds that have had prior exposure to mild heat stress, and those that have not, this project will integrate biology and engineering approaches to develop a model to predict when stressful events negatively impact reproduction. Further, the investigators will examine how stress resistance and resilience can be transmitted to the next generation. This project will integrate biology and engineering in research and educational activities for students in Alabama. First, to highlight the connection between biology and engineering, the project will teach high school students about technologies inspired by nature in a summer program. Second, this project will organize a career fair, showcasing careers that integrate science and engineering degrees and giving opportunities for the participants to meet professionals from diverse backgrounds. Finally, this project will develop a hands-on workshop where students in biology and engineering learn how to turn data into mathematical models and active learning courses on functional genomics and epigenetics. By incorporating physiology, genomics, and engineering through research and education, the project will provide training, mentorship, and opportunities to nurture interdisciplinary mindset in early-stage scientists.

Organisms across taxa can increase stress resilience when conditioned to a mild stressor during development. At the same time, severe levels of stress may decrease fitness. This context-dependency makes it difficult to predict how a shift in an environment alters the fitness outcome of an individual and success of a population. Several theoretical models have been put forth to characterize responses to a stressor, yet predictive models and reliable biomarkers of stress resistance and resilience are still lacking. To bridge this gap, the goal of this project is to utilize path analysis and Damage-Healing Mechanics from material engineering to develop mechanistic and predictive mathematical models, linking developmental and adult environments, epigenetic modifications, stress-induced molecular and cellular damage, and fitness indices. Specifically, this project will test the hypotheses that persistent damage, such as DNA damage and lipid peroxidation, lowers reproductive output and that stress conditioning increases stress resistance through epigenetic regulation of genes controlling damage protection, repair, and removal. Using a previously established protocol of heat conditioning in zebra finches (Taeniopygia guttata), the present project will assess 1) whether mild heat conditioning in juveniles turns on damage protective mechanisms such as heat shock proteins, antioxidants, and DNA repair, reduces accumulation of damage induced by heat stress in adulthood, and minimizes the negative effects of heat stress on reproductive output, and 2) whether heat conditioning in the F1 generation causes epigenetic modification of genes regulating damage protection, repair, and removal in the F2 generation.

This project was co-funded by the Integrative Ecological Physiology and the Physiological Mechanisms and Biomechanics programs in Integrative Organismal Systems.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.