Meeting Abstract
P2.108 Wednesday, Jan. 5 HIF-mediated growth suppression in Drosophila melanogaster reared in moderate hypoxia HARRISON, J.F.*; RAMSEY, K.A.; DOHRENWEND, S.; HEINRICH, S; FARZIN, M.; GREENLEE, K.J.; Arizona State University; Arizona State University; Arizona State University; Arizona State University; Arizona State University; North Dakota State University j.harrison@asu.edu
Although hypoxia reduces the growth and size of many animals, the mechanisms responsible remain poorly understood. In fruit or vinegar flies, Drosophila melanogaster, rearing in moderate hypoxia (10 kPa) reduces survival, fecundity, body size, feeding and growth rates, while extending development time. Critical PO2 values for metabolic rates are below 4 kPa for both larvae and adults, arguing against direct limitation of ATP production as the mechanism of suppression of growth and size by oxygen in 10 kPa atmospheres. Both hypoxia-inducible factor (HIF) and nitric oxide signaling have been demonstrated to mediate responses of Drosophila to severe hypoxia, but it is not known whether these pathways operate in moderate hypoxia. We found that hypoxia-response elements were expressed in 10 kPa PO2, suggesting activation of hypoxia inducible factor (HIF). Knockdown of HIF signaling using RNA interference of tango expression reduced the effect of hypoxia on adult size, supporting an important role for HIF-signaling in the suppression of growth in moderate hypoxia. However, suppression of HIF signaling did not affect survival during hypoxia, suggesting that the mortality effects of hypoxia are not tightly linked to growth-regulation. Supported by NSF EAR: 0746352 and IBN 0419704 to JFH.
