Comparative metatranscriptomics of Ifremeria nautilei bacterial symbionts

Chemoautotrophic symbioses influence biogeochemical cycles at deep-sea hydrothermal vents, yet we know very little about how these associations respond physiologically to fluctuations in the vent environment. The snail Ifremeria nautilei inhabits chemically heterogenous vent sites in the SW Pacific, where it derives nutrition from the autotrophic activity of sulfur oxidizing bacterial endosymbionts. To investigate the effect of electron donor species and concentration on endosymbiont metabolism, snails (n = 12) were collected from the Lau Basin hydrothermal system and placed in pressurized aquaria under four conditions i) no electron donor (ND), ii) 100 µM hydrogen sulfide (LS), iii) 350 µM hydrogen sulfide (HS), and iv) 300 µM thiosulfate (TS). Gill tissues were subsequently sampled and RNAseq was performed to determine gene expression under different experimental conditions.