Meeting Abstract

75.3  Monday, Jan. 6 08:30  The consequences of thermal stress on early embryonic development: from cells to the whole-organism LOCKWOOD, B.L.*; MONTOOTH, K.L.; Indiana University; Indiana University bllockwo@indiana.edu

For ectothermic organisms like Drosophila, changes in environmental temperature alter cellular processes. During early development, a rapid series of mitotic divisions bring an embryo from having a single nucleus to having thousands of nuclei, before gastrulation occurs and cell differentiation begins to take place. These early mitotic divisions are driven by the cytoskeleton, and previous work in cell culture has shown the cytoskeleton to be sensitive to thermal stress. Does thermal variability disrupt developmental progression by adversely affecting the cytoskeleton? Here we use confocal fluorescence microscopy to investigate the effects of thermal stress on the cytoskeleton in vivo in early stage embryos of Drosophila melanogaster. We find that exposure of eggs to heat stress causes gross defects in cytoskeletal arrangement and leads to the disruption of mitosis and cellularization of the blastoderm, both key developmental events. Moreover, brief heat stress events experienced in early embryogenesis lead to a decrease in survival to adulthood. These findings suggest that the thermal sensitivity of the cytoskeleton plays a key role in determining thermal tolerance at both the cellular and whole-organism levels.