Hypoxia and hypobaria exert separate effects on hypoxia inducible factor (SIMA) expression in female Drosophila melanogaster.

Alanna Connolly, Jaden Buchanan, Kyle Sears and Dr. David S. Richard. Department of Biology, Susquehanna University, Selinsgrove, PA 17870

Global surface temperatures have risen alarmingly over recent decades due to anthropogenic greenhouse gas emissions, especially in the Himalayas where new higher altitude-low atmospheric pressure habitat is now potentially available for vertical insect migration. While other studies have examined the effects of low oxygen (hypoxia) on insect development, we are aware of none that have examined the effects of low pressure (hypobaria). Using a self-built hypobaric chamber, we exposed newly emerged fruit flies (Drosophila melanogaster) to a simulated altitude of 5,500m ASL where atmospheric pressure is 50% of that of sea level. Low levels of oxygen at normal pressure typically stimulate the adaptive expression of hypoxia inducible factor genes (HIFs). Exposure to simulated high altitude unexpectedly suppressed ovarian and female whole-body expression of the HIF gene (SIMA), as measured by Real-Time PCR, indicating that the effects of low levels of oxygen and low pressure may be distinct. To separate these effects, we used a 2x atmospheric oxygen gas mixture at low pressure to simulate the effect of a sea-level oxygen pressure at high altitude. Similarly, we used a 0.5x oxygen mix at normal pressure to compare gene expression against air at high altitude. Co-exposure to low pressure and normal oxygen levels drastically suppressed SIMA production.  Co-exposure to low pressure and low oxygen lowered SIMA production below the level normally seen when flies were exposed to low oxygen levels at normal pressure. Taken together, these data indicate that there may be a novel pressure-sensing system in flies that is separate from the hypoxia sensing systems (HIFs/ HIF-prolyl-hydroxylases) that would normally regulate responses to low levels of oxygen availability. The nature of this novel mechanism is under investigation but we are unaware of any being reported in the literature in any organism to date.

Additional Abstract Information

Presenters: Alanna Connolly, Jaden Buchanan, Kyle Sears

Institution: Susquehanna University

Type: Poster

Subject: Biology

Status: Approved

Time and Location

Session: Poster 3
Date/Time: Mon 4:30pm-5:30pm
Session Number: 3024