Experimental Selection for Drosophila Survival in Extremely Low O2 Environments. Drosophila melanogaster

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 Overall design: 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.

本研究通过多世代长期实验选育，获得了可在极低且通常具有致死性的氧气（O2）条件（4%~5% O2）下永久存活的黑腹果蝇（Drosophila melanogaster）品系。该类品系与对照果蝇相比存在显著的表型分化，具体表现为：无氧（anoxia）暴露后的恢复时长缩短、低氧（hypoxia）条件下的氧气消耗速率升高，同时因细胞增殖能力下降与细胞体积减小共同导致体重降低。本研究通过基因表达谱分析（gene expression profiling）鉴定了低氧适应果蝇体内的转录本水平变化，并证实众多对应基因的突变可赋予果蝇在极低氧气条件下的存活能力。
关键词：低氧适应的遗传基础（genetic bases of hypoxia adaptation）
整体实验设计：将27个同基因（isogenic）黑腹果蝇品系混合，在培养环境氧气水平持续降低的条件下开展多世代长期选育。通过基因芯片（microarray）技术，比较低氧适应果蝇与同世代未受选择的对照果蝇之间的基因表达差异。以27个亲本品系的混合RNA样本作为通用参照。