Meeting Abstract

P1-211  Thursday, Jan. 4 15:30 – 17:30  Acidified Oceans and Octopuses: How Gene Expression in Octopus rubescens Changes in Elevated CO₂ PEKAR, KJ*; CULLER, ME; ONTHANK , KL; Walla Walla University; Walla Walla University; Walla Walla University katherine.pekar@wallawalla.edu https://gab.wallawalla.edu/~kirt.onthank/index.html

Global anthropogenic increases in atmospheric carbon dioxide contribute to decreased marine pH. This process, known as ocean acidification, is predicted to increase ocean average carbon dioxide pressure from 400 μatm to 750 μatm and decrease ocean average pH from 8.1 to 7.8 by 2100. To better understand the response of octopuses to high CO₂ and low pH, we kept three Octopus rubescens in a controlled high CO₂ environment and three O. rubescens in a control CO₂ environment. After ten days, we excised gill tissue and used mRNA sequencing to determine differential gene expression between treatment and control octopuses. Using the DESeq2 package in R, differential expression analysis identified over 1,200 apparent differentially expressed genes (DEGs) between treatments over a multitude of pathways. Several DEGs indicate upregulation of anaerobic metabolic processes and downregulation of aerobic metabolic processes in elevated CO₂. In conjunction with previous research that found octopuses have higher ventilation rates and increased critical oxygen pressure in elevated CO₂, our findings suggest that octopuses in acidified water may be struggling to breathe.