| I am interested in how organisms respond and ultimately adapt to their environment at a physiological, biochemical, and molecular level. I am especially interested in how embryos and larvae are affected by their environment, and how they deal with environmental stress. In many cases, embryos are the most sensitive life history stage to environmental preturbations. The basis for this increased sensitivity remains a mystery, due principally to a lack of information on developmental physiology. How are developmental, cell cycle, and metabolic pathways integrated during development and how are these interactions affected by the environment? How and when are physiological traits acquired during development? How is physiological homeostasis maintained in embryos and adults exposed to a highly variable environment, and are these responses different? Theseare examples of the types of questions that fuel my interest in biology.
I have chosen the annual killfish Austrofundulus limnaeus as the primary model organism for my studies. These fish live in small ephemeral ponds (mud puddles) in regions of northern South America that experience pronounced dry and rainy seasons. These fish are in general very tolerant to extremes in temperature, oxygen availability, salinity, and pH. The adult fish are not dehydration-tolerant and thus will die when their ponds dry. Populations survive in a given location due to the production of drought-resistant diapausing embryos encased in the drying mud. Diapause may interrupt development at three distinct developmental stages in annual killfish. Embryos entering diapause arrest development and enter a state of metabolic dormancy. The predictable arrest of cell proliferation and metabolism associated with entry into diapause makes this an excellent system for studies on the control of the cell cycle and regulation of metabolic pathways.
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