Molecular Phylogeny of Flightin and the Evolution of Insect Flight Muscle

University Of Vermont & State Agricultural College, Burlington VT

Investigators

Abstract

The origin and evolution of insect flight is of major interest in evolutionary biology. More than half of all living species identified to date are insects making Insecta the most diverse class on Earth and arguably among the most successful animals in natural history. Flightin is a muscle protein known to be essential for flight in the fruit fly, Drosophila melanogaster. These studies will combine phylogenetic analyses with biochemical techniques to examine the rate of evolution of flightin among Drosophila lineages (aim 1) and to examine the phylogenetic distribution and tissue expression of flightin across insects and crustaceans (aim 2). The goal of the first aim is to test the hypothesis that flightin is under dual evolutionary constraints (purifying and positive selection) to fulfill a conserved muscle physiological function and a rapidly evolving behavior-associated function. This hypothesis will be tested by using Drosophila phylogeny to analyze the evolution of flightin, its propensity for multiple phosphorylations, and flight muscle biomechanical properties. The goal of the second aim is to test a key hypothesis that the assignation of flightin to the flight muscles correlates with the extensive insect radiation during the late Carboniferous (~290 Mya). This hypothesis will be examined by surveying increasingly deeper nodes in Pancrustacea phylogeny, from Holometabola to Crustacea, for expression of flightin by RNA, protein, and immunocytological analyses. The achievement of the stated goals will help to elucidate the mechanistic links between molecular physiology and cellular mechanics of muscle and the ecobehavioral aerodynamics and evolution of insects, and will pave the way towards a synthesis of the macro-and microevolutionary trends in the most prolific terrestrial metazoan. Additional broader impacts of this research are primarily in the areas of education and the generation of biological reagents for the research communities. This research will provide training opportunities for undergraduate and graduate students, and occasional high school students, and inclusiveness of students and research personnel from underrepresented communities and disadvantaged backgrounds. Knowledge generated from this research will find its way to advanced undergraduate and graduate special topic courses and to review articles and book chapters intended for the broader scientific community. Results will be broadly disseminated by undergraduate and graduate students who will present their work at scientific meetings and will publish their studies in peer-reviewed journals.