Deans Lab
The Deans Lab is part of the Biological Sciences Department at the University of Alabama Huntsville. Here, we are focused on understanding mechanisms of adaptation, i.e., the diverse ways that organisms respond to changing environments. We use integrative approaches to understand the organization and dynamics of these complex biological processes to better understand their functioning and evolution. You can find more information about specific projects below.
If you are interesting in join the lab, please feel free to contact me via email (cad0744@uah.edu)
Research Interests
Nutrition and Stress Interactions
Nutrition is a strong mediator of plasticity and can impact many facets of animal fitness. Studies employing a geometric framework have shown that the relative amount of dietary protein (P) and carbohydrates (C), denoted by a P:C ratio, have stronger impacts on animal fitness than the absolute concentrations of these nutrients in isolation. Using several agricultural pest/invasive species models (H. zea, D. suzukii, L. hesperus), I explore how dietary P:C ratios (indicative of different plant tissues) impact insect susceptibility to insecticides and other stressors. I am also interested in understanding the mechanisms that mediate the effects of dietary P:C ratio on performance via the interaction between the insulin, TOR, and ampK nutrient-sensing pathways.
Food as an Environmental Signal
The primary role of dietary nutrients is to provide the compounds that fuel physiological processes, but our food also contains valuable information about the environment that can alter physiology in adaptive ways. Dietary restriction (DR) is a phenomenon whereby feeding on a slightly limited diet (reduced in calories or protein) produces a reversible phenotype exhibiting a trade-off between lower reproductive output and increased median/maximum lifespan. This highly conserved response is not due to metabolic constraints but rather a dietary signal of poor environmental conditions that causes an up-regulation of cellular defenses. In flies, the DR phenotype is reversed upon exposure to the odor of high quality diet, further substantiating a role for diet to act as a signal. My research focuses on understanding this aspect of nutrition by identifying the dietary components that can mediate changes in insect physiology via signaling pathways and their mechanisms, particularly in an ecological context.
Anticipatory Mechanisms
The classical metabolic view of nutrition is largely seen as a reactive process. Nutrients are sensed in the gut triggering the release of digestive enzymes with subsequent downstream effects. However, Pavlov's seminal work on digestion in the early 1900s demonstrated that various dietary cues caused an anticipatory release of gastric enzymes, what he called "psychic secretions". Since then, several other examples of anticipatory processes and predictive biochemical networks have gained visibility in many different fields, particularly among primitive taxa without complex neurological systems. Some examples include: dietary restriction, plant eavesdropping, priming/preconditioning, circadian rhythms, hormesis, and transgenerational effects. My work focuses on identifying and assessing these anticipatory process, particularly in non-cognitive organisms, understanding their mechanisms, and assessing their role in fundamental biological processes.