Meeting Abstract

32.1  Monday, Jan. 5 08:00  Deep sequencing of the hepatopancreas transcriptome reveals new isoforms of hemocyanin and their regulation in response to low O2/high CO2 in the Pacific whiteleg shrimp, Litopenaeus vannamei JOHNSON , JG*; PAUL, M; KNIFFIN, CD; ANDERSON, PE; BURNETT, LE; BURNETT, KG; College of Charleston; College of Charleston; College of Charleston; College of Charleston; College of Charleston; College of Charleston jill.johnson821@gmail.com

Acclimation to low O₂ in many organisms involves changes at the level of the transcriptome. Here we used high throughput RNA sequencing to explore the global transcriptomic response and specific involvement of new isoforms of hemocyanin (Hc) in the multistressor low O₂/high CO₂ response. Hepatopancreas mRNA of juvenile L.vannamei exposed to air-saturated water, low O₂, or low O₂/high CO₂ for 4 or 24 h, was pooled, sequenced (HiSeq 2500) and assembled (Trinity: 52,190 contigs) to create a deep strand-specific reference transcriptome. Annotation of the assembly revealed sequences encoding the single large and small Hc subunits, two previously undescribed full-length isoforms of the large subunit, and 12 partial sequences. mRNA of individual shrimp was sequenced (6/treatment); resulting reads were quantified (eXpress) and regulated genes identified from pairwise comparisons at each time (DESeq2). GO term enrichment (Roff- Bentzen; p < 0.0001) and PCA analysis demonstrated a distinct pattern of regulation between prolonged low O₂ and low O₂/high CO₂ treatments, showcasing the stabilization of energetically costly translational machinery, mobilization of energy stores, and downregulation of the ubiquitin/proteasomal degradation machinery. The antagonistic effect of CO₂ on the transcriptomic response of Hc subunits to low O₂ was confirmed in this study, and we are exploring the importance of these novel full length and partial isoforms to the structural and functional response of Hc in low O₂ alone and with high CO₂ (NSF IOS-1147008).