Transcriptomic analysis of cultured kuruma shrimp primary lymphoid organ cells for identifying key cascades hindering sustainable culture

The progress of virology research in shrimp has been hampered by a lack of immortalized shrimp cell lines, and even long-term and stable primary cell cultures have not been perfectly achieved. Here, transcriptomic analysis of primary lymphoid cells in kuruma shrimp Marsupenaeus japonicus was performed to understand gene expression changes and stressors under existing culture conditions. In our optimized culture, the primary cells showed dead cell increases on days 3–4 and 6–7 after seeding. Next, we performed transcriptomic analysis at four time points (days 1, 3, 4, and 6 after tissue seeding), and RNA sequencing revealed that detected genes could be divided into three groups according to their expression changes: (1) downregulated on days 3–6, (2) upregulated on days 3–4, and (3) upregulated on day 6. Group 1 included platelet-derived growth factor receptor alpha and vascular endothelial growth factor 3 ( MjVEGF3 ). Consistently, quantitative real-time polymerase chain reaction (qPCR) results showed a significant decrease in MjVEGF3 and its receptor ( MjVEGFR ) expression. These results suggest the importance of supplementation to recover VEGF signaling in the proper time-dependent manner for long and stable culture of shrimp lymphoid organ cells.