Meeting Abstract

25.6  Jan. 5  The Cellular-Hydrostat Network Model of the Notochord of the Atlantic hagfish, Myxine glutinosa COMBIE, K*; ENGEL, G; KOOB, T; LONG, J; Vassar College; Vassar College; Mount Desert Island Biological Laboratory; Vassar College kecombie@vassar.edu

We hypothesized that the adult hagfish notochord’s network of interconnected, vacuolated cells compartmentalizes and pressurizes fluid intracellularly, creating elastic-solid mechanical behavior in the absence of an extracellular matrix. Notochords were dissected, ligated, and quartered axially, producing sealed segments for dynamic bending tests. Half of the specimens were incubated in hagfish ringers on ice; the other half were frozen and thawed three times in hagfish ringers before bending tests. This treatment lysed the cells, which resulted in a significant decrease in the complex modulus, E*, and the storage modulus, E’. There was no difference in the loss modulus, E”, or tan delta. We propose a biological design principle, the cellular-hydrostat network, that links the notochord’s bending function during swimming and the intermediate filament bounded, polyelectrolyte-filled vacuoles in the cells of the notochord lumen. Supported by the National Science Foundation grant DBI-0442269.