974A Poster - 15. Models of human disease
Thursday April 07, 2:00 PM - 4:00 PM

Authors:
Tsering Stobdan; Nicholas Wen; Dan Zhou; Gabriel Haddad

Affiliation: University of California San Diego

Keywords:
r. stress; h. selection

Hypoxia plays a critical role in multiple disease conditions. The highly conserved cellular and molecular mechanisms between flies and higher eukaryotes, including humans, have made Drosophila a valuable organism to identify hypoxia-sensitive cells and genes critical to hypoxic environment. Since the life cycle of Drosophila constitutes four morphologically distinct developmental stages, a stage specific identification of mechanisms involving hypoxia response becomes critical. Although the effect of hypoxia on the embryo, larvae or adult is frequently reported, the effect on pupae or pupation is less clear. In this study, we examined different stages of Drosophila development for its hypoxia sensitivity and identified pupae as a critical stage affecting their subsequent eclosion. We show that the continuous exposure to 4% O₂, from embryo to pupae is lethal. However, returning to normoxia at early, mid and late pupae stage would results in 99.6%, 66.1% and 54.4% eclosion, respectively. Similarly, returning to normoxia at 1^st, 2^nd or 3^rd instar larvae resulted in >97% eclosion. In contrast, exposing the normoxia-grown larvae or pupae to 4% O₂ is lethal. Additionally, exposing early pupae for 3 days of 4% O₂ led to only 6.1% eclosion, while shorter exposure such as for 2 days or 1 day to 4% O₂ resulted in significantly higher eclosion of 66.7% and 96.4%. These results indicate that pupation is a very sensitive stage to hypoxia during Drosophila development. Overall, these results will be the basis for the identification of critical genes involved in hypoxia sensitivity or tolerance during development.