This 1974 study investigated the requirement of arginine for replication of Marek's disease herpes virus (MDHV) in Japanese quail embryo fibroblast cell cultures. The researchers found that arginine is essential for MDHV replication. When arginine was omitted from the culture medium, plaque-forming activity was completely inhibited in arginine-depleted cells but resumed when arginine was restored. The viral genome remained viable for up to 10 days in arginine-free conditions. Arginine became necessary around 12 hours after virus inoculation. Crucially, arginine deprivation did not affect virus adsorption, penetration, or DNA synthesis but specifically prevented the formation of viral structural proteins, as detected by immunofluorescent antibody staining. The enzyme arginase, which depletes arginine, also completely blocked viral replication. These findings demonstrate that while early steps of MDHV infection occur normally without arginine, the amino acid is specifically required for late viral protein synthesis and assembly. The results parallel earlier observations with herpes simplex virus and establish arginine as a critical nutrient for cell-associated herpesvirus replication.

Key findings

• Arginine is essential for MDHV replication; its omission completely inhibits plaque formation in arginine-depleted cells but plaques resume upon arginine restoration
• Arginine deprivation does not affect virus adsorption, penetration, or DNA synthesis but specifically prevents viral structural protein formation
• The viral genome remains viable and recoverable for up to 10 days in arginine-free medium, indicating early replication steps proceed normally without arginine
• Arginine becomes required around 12 hours post-inoculation, suggesting it is needed for late stages of viral protein synthesis and virion assembly
• Complete inhibition of plaque formation occurs when arginase enzyme depletes arginine from complete medium, confirming the amino acid requirement