Transcriptome assemblies of wild Litopenaeus vannamei and wild Farfantepenaeus aztecus Assembly

RNA-Seq data were collected from the hepatopancreas tissues of wild-caught Pacific whiteleg shrimp Litopenaeus vannamei, and wild-caught Atlantic brown shrimp Farfantepenaeus aztecus. De novo assembly yielded high-quality stranded transcriptomes. Manual curation of the hemocyanin subunits from all three groups of penaeid shrimp confirmed the existence of a small gamma-type hemocyanin subunit (HcS), greater sequence diversity in the large gamma-type hemocyanin subunit than previously identified (HcL1-3 isoforms) and expression of a beta-type hemocyanin subunit (HcB) previously unidentified in Penaeid shrimp. Relative abundance of transcripts encoding these hemocyanin isoforms differed within and among the three species/strains. Exposure to low O2 induced expression of all of the subunits in aquacultured L. vannamei. With concurrent exposure to high CO2, the number of gamma-type hemocyanin transcripts decreased while the expression of beta-type transcripts remained unchanged. Together with functional data for hemocyanins in the same shrimp species/strains, the RNA-Seq approach shows great promise to provide new insights into the connection between sequence, protein structure, and physiological function of respiratory pigments in this decapod crustacean family.