Hypoxia-induced gene expression profiling in the euryoxic fish Gillichthysmirabilis

Hypoxia is important in both biomedical and environmental contexts and nece ssitates rapid adaptive changes in metabolic organization. Mammals, as air breathers, have a limited capacity to withstand sustained exposure to hypox ia. By contrast, some aquatic animals, such as certain fishes, are routinel y exposed and resistant to severe environmental hypoxia. Understanding the changes in gene expression in fishes exposed to hypoxic stress could reveal novel mechanisms of tolerance that may shed new light on hypoxia and ische mia in higher vertebrates. Using cDNA microarrays, we have studied gene exp ression in a hypoxia-tolerant burrow-dwelling goby fish, Gillichthys mirabi lis. We show that a coherent picture of a complex transcriptional response can be generated for a nonmodel organism for which sequence data were unava ilable. We demonstrate that: (i) although certain shifts in gene expression mirror changes in mammals, novel genes are differentially expressed in fis h; and (ii) tissue-specific patterns of expression reflect the different me tabolic roles of tissues during hypoxia.