Tolerance of bivalve mollusc hemocytes to variable oxygen availability: a mitochondrial origin?

International audience; Bivalve molluscs survive lack of oxygen and may present cellular characteristics allowing tolerance tooxygen deprivation. The objective of the present work was to determine in vitro responses of circulating cells (i.e.,hemocytes) of Pacific oyster, Crassostrea gigas, to oxygen deprivation by analysis of mitochondrial membrane potential(ΔΨm) and reactive oxygen species (ROS) production. Hemocytes submitted to oxygen deprivation showed areduced ROS production and an increased ΔΨm. Confrontation of present results with recently reported findings allowsus to hypothesize the existence of an alternative mitochondrial reductase, and the involvement of mitochondrial potassiumchannel in maintenance of ΔΨm. Tolerance of bivalve hemocytes to variable oxygen availability appears, at leastpartially, related to mitochondrial specificities.