Expressão do gene HIF-1α durante a exposição do Ciclídeo Astronotus crassipinnis (Heckel, 1840) à hipóxia

Abstract

The aquatic habitats of the Amazon basin present deep oxygen level variation, and many aquatic animals developed biochemical and physiological adaptations to survive such changes. The advanced teleost Astronotus crassipinnis is tolerant to hypoxia and has the ability to depress its metabolic rate (oxygen consumption) and to increase its anaerobic activity when exposed to hypoxia episodes. Hypoxia-inducible factor-1α (HIF-1α) is the first gene related to hypoxia-tolerance, being regulated under these circumstances to maintain regular cellular function and control anaerobic metabolism. In the present work we studied HIF-1α expression and correlated the gene expression with changes in the metabolism of Astronotus crassipinnis exposed to 1, 3, and 5 hours of hypoxia, followed by 3 hours of recovery. The results show that A. crassipinnis presents metabolic depression under hypoxia and increases its anaerobic metabolism, and differentially regulates this gene in each of the studied tissues, with positive relationship with its metabolic profile, suggesting that HIF-1α might be the main factor to regulate responses to hypoxia tolerance.