The cDNA Cloning, Sequence Analysis and Expression of Dopa Decarboxylase Gene in Procambarus clarkii

PurposeProcambarus clarkii belongs to the phylum arthropoda crustaceans, decapoda, also known as crayfish. As a key enzyme in innate immune response, dopa decarboxylase plays a key role in resisting the invasion of foreign pathogens. The aim of this study was to amplify Pc-ddc gene from P. clarkii and to obtain its expression pattern.

MethodsThe expression vector of Escherichia coli was constructed by molecular biology technology and analyzed by bioinformatics, at the same time, the qRT-PCR technology was applied to analysis the mRNA expression profiles of tissues.

ResultsThe full length of cDNA open reading frame (ORF) sequence of Pc-ddc gene of crayfish was 1 425 bp, encoding 474 amino acid residues, and the theoretical molecular weight of polypeptide was 52.99 ku. The molecular formula of the protein was C₂₃₈₄H₃₆₈₉N₆₄₇O₆₇₄S₂₅, and the isoelectric point was 5.98. It was a weakly acidic protein with no signal peptide at the N-terminal. Next, subcellular localization showed that Pc-DDC protein was the most abundant in mitochondria. Pc-ddc mRNA was widely expressed in the six tissues of P. clarkii with highest expression level in lymph organ.

ConclusionThese experimental data provided a supplement for the exploration of innate immune system of P. clarkii.