Meeting Abstract

P1.19  Tuesday, Jan. 4  Anatomy of the tracheole system supplying Drosophila flight muscle WATERS, James S; HEINRICH, Stephanie M.*; HARRISON, Jon F.; Arizona State University; Arizona State University; Arizona State University smheinri@asu.edu

Insect tracheal systems provide conduits for transporting air into and out of the insect and throughout its tissues. Extensive research has focused on the anatomy and morphology of the parts of this system including spiracles and tracheae that make up the main pathways for air-flow. Gas exchange however, is understood to take place primarily at the distal end of the tracheal system, across the surface areas provided by the tracheoles. In this study, we investigated the anatomy, structure, and phenotypic plasticity of tracheole networks within the thorax of Drosophila melanogaster . Flies were reared from egg to adulthood in 10, 21 or 40% oxygen atmospheres, and anesthetized, dissected, and fixed on the fourth day of adulthood. The tracheoles were imaged using confocal microscopy, taking advantage of the autofluorescence of tracheal chitin to visualize tracheae and tracheoles ranging from 50 to 0.2 micrometers in diameter. Tracheole structure was assessed using a variety of methods including randomized point counting, individual tracheole counts and measurements of tracheole diameters and distributions. The primary branching structures were not influenced by the concentration of oxygen in the rearing environment. However, tracheal density within the flight muscle varied strongly and inversely with the concentration of atmospheric oxygen, demonstrating that the adult tracheal system exhibits a compensatory response to the larval oxygen environment. This research was supported by NSF IBN 0419704 to JFH.