Isolation and characterization of a bromodomain-containing protein cDNA sequence from Litopenaeus vannamei and its expression analysis

Bromodomain-containing protein (BCP) is a highly conservative protein, which belongs to the bromodomain and extraterminal (BET) protein superfamily. BCP can regulate gene replication and transcription by recruiting different chromosome modifying proteins, and the change of its expression is often associated with the occurrence of tumor and inflammation. Based on the transcriptomic analysis, a cDNA sequence of BCP gene (Lv-BRD), 2 229 bp in length, was isolated from the hemocytes of Litopenaeus vannamei in this study. The sequence has been deposited in GenBank with accession number of MH638256. Using online tools, the sequence was characterized. The deduced protein sequence of Lv-BRD has a conservative bromine domain, indicating that it may be involved in the regulation of cell cycle. Tissue/organ expression was analyzed by qPCR and the result showed that Lv-BRD was mainly expressed in hemocytes, hepatopancreas and gills of shrimp. Expression of Lv-BRD in hemocytes increased significantly in the early stage (0.5–12 hours past infection, hpi) challenge by white spot syndrome virus (WSSV), B. thuringiensis and V. parahemolyticus, suggesting that Lv-BRD is involved in the innate immune response to pathogens in shrimp. These results provided a basis for further studies on the function and mechanism of Lv-BRD in antiviral immunity and interferon regulation of L. vannamei.