Recent studies have shown that
trehalose plays a protective role in yeast in a variety of stresses, including heat, freezing and thawing,
dehydration, hyperosmotic
shock, and
oxidant injury. Because (a) heat shock and
anoxia share mechanisms that allow organisms to survive, (b) Drosophila melanogaster is tolerant to
anoxia, and (c)
trehalose is present in flies and is metabolically active, we asked whether
trehalose can protect against anoxic stress. Here we report on a new role of
trehalose in
anoxia resistance in Drosophila. We first cloned the gene
trehalose-6-phosphate synthase (tps1), which synthesizes
trehalose, and examined the effect of tps1 overexpression as well as mutation on the resistance of Drosophila to
anoxia. Upon induction of tps1,
trehalose increased, and this was associated with increased tolerance to
anoxia. Furthermore, in vitro experiments showed that
trehalose reduced
protein aggregation caused by
anoxia. Homozygous tps1 mutant (P-
element insertion into the third intron of the gene) leads to lethality at an early larval stage, and excision of the P-
element rescues totally the phenotype. We conclude that
trehalose contributes to
anoxia tolerance in flies; this protection is likely to be due to a reduction of
protein aggregation.