P3.101 Monday, Jan. 6 15:30 Depth adaptation in hadal crustaceans: potential piezolytes increase with depth in the tissues of marine amphipods WALLACE, G/T*; JAMIESON, A/J; BARTLETT, D/H; CAMERON, J; GOTZ, M/G; YANCEY, P/H; Whitman College; The University of Aberdeen; Scripps Institution of Oceanography; DEEPSEA CHALLENGE; Whitman College; Whitman College email@example.com
A longstanding question in deep-sea biology is how organisms adapt to extreme hydrostatic pressures of hadal zones. One hypothesis involves piezolytes that counteract the protein-destabilizing effects of high pressure. Bony fish appear to adapt to high pressure with the piezolyte trimethylamine oxide (TMAO), which increases intracellularly with depth and allows them to exist down to 8 km. The mechanisms used to cope with pressure at even greater depths are still unclear. To address this question, we examined the tissues of amphipods (Alicella spp., Hirondellea spp., Lysianassidae spp., and Talitridae sp.) collected from depths of 0.0, 1.7, 2.3, 7.9, 8.1, 8.4, 9.3, and 10.9 km. Deep specimens were caught using baited landers in the Northwest Hawaiian Islands and the New Britain, Kermadec, and Mariana Trenches. Using HPLC, NMR, mass spectrometry, and free amino acid analysis, we identified concentrated molecules that may be piezolytes in these animals. Shallow species predominantly contain the non-piezolytes taurine, glycine, betaine, and alanine. As depth increases, these compounds are largely replaced by methylamines (TMAO and glycerophosphorylcholine), hydrophobic amino acids (valine, methionine, isoleucine and leucine), and the polyol scyllo-inositol. Of these molecules, only TMAO has been studied as a protein stabilizer against pressure. There may be a synergistic interaction among several piezolytes in hadal crustaceans; unlike fishes’ use of TMAO as a primary piezolyte, marine amphipods may have evolved a more complex solution to the protein-perturbing effects of high pressure. Funding: National Science and Blue Planet Marine Research Foundations.