Experimental Selection for Drosophila Survival in Extremely Low O2 Environments

We have used long-term experimental selection over many generations to obtain Drosophila melanogaster strains that can live perpetually in extremely low, normally lethal O2 conditions (4-5% O2). These strains show a dramatic phenotypic divergence from control animals, including a decreased recovery time after anoxia, a higher rate of O2 consumption in hypoxic conditions, and a decrease in body mass due to both decreased cell proliferation and cell size. We used gene expression profiling to identify altered transcript levels in the adapted flies and we show that mutations in many of the corresponding genes confer the ability to survive under extremely low O2 conditions. Keywords: genetic bases of hypoxia adaptation 27 isogenic D. melanogaster Lines were pooled and following long-term selection over generations with decreased oxygen level in the culture environment. The differences in gene expression were compared between adapted flies and generation matched naive controls by microarray. Pooled RNA samples from 27 parental lines were used as common reference.