Physiological and life history differences arising from variation in tracheal development and mitochondrial aging in an ecological model organism

This study continues a transformation in molecular ecology: the ability to find and study genetic variation affecting phenotypes that are the basis for fitness differences in ecological model systems. Results from this study will connect mechanistically genetic variation encoding a metabolic enzyme to a signaling pathway, development, morphology, physiology and performance in nature, at the level of individuals, populations and (via the research in other labs) a metapopulation. The results are informative for this ecological model system and for a broader understanding of fitness tradeoffs, maintenance of genetic variation in populations by balancing selection, and aging. An insect model system will be used to examine how genetic variation and physiological traits interact with landscape features and population dynamics. New physiological insight will also be obtained via determination of how the hypoxia inducible factor signaling pathway controls both the development of the oxygen delivery network (tracheae) and mitochondrial aging. This research will examine experimentally how genetic variation in a gene encoding a central metabolic enzyme (succinate dehydrogenase; Sdh) affects life history, differences in tracheal network development and mitochondrial aging in an ecological context. Complementary experiments employing available Sdh mutants in the model system Drosophila will be used to test mechanistic relationships. The central thesis is that differences in tracheal development affect fitness tradeoffs via effects on flight metabolism, respiratory water loss, survival of summer drying of the habitat, and the rate of aging of flight muscle mitochondria.

The PI and his students have helped labs in the U.S., Europe and Australia perform their first transcriptome studies. The PI and his team are now scaling up this effort by working with a consortium of more than 100 undergraduate institutions to help them enhance undergraduate teaching and faculty training in functional genomics. The personnel of this project will work with the Genome Consortium for Active Teaching NextGen Sequencing Group (GCAT-SEEK), headed by nearby Juniata College, to instruct undergraduates directly and, via workshops, train interested faculty across the entire array of member institutions. These workshops are tailored for undergraduate educators and students who are novices with respect to NextGen technology and bioinformatics. The workshop training will assist in all stages of experimental design through assessment, and provide participants with active learning modules that are easy to integrate into classes. The PI is also involved heavily in student training (including a number of students who are under-represented minorities and women), and communicating science with the general public.