Transcriptomic responses of sponge holobionts to in situ, seasonal anoxia and hypoxia

Deoxygenation can be fatal for many marine animals; however, some sponge species are tolerant of hypoxia and anoxia. Indeed, two sponge species, Eurypon sp. 2 and Hymeraphia stellif-era, survive seasonal anoxia for months at a time. To understand their tolerance mechanisms, we performed differential gene expression analyses on the sponges, their mitochondria and their microbial symbionts under in situ conditions of normoxia, hypoxia and anoxia. Each species