Revisiting Porcine Circovirus Infection: Recent Insights and Its Significance in the Piggery Sector

Figures

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  Figure 1. Genome organization of porcine circovirus.

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  Figure 2. Worldwide occurrence of different species of PCVs.

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  Figure 3. Phylogenetic relationship among four species of porcine circoviruses.

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  Figure 4. Life cycle of PCV. 1 Binding of virus with the cell surface receptor; 2 Entry of the virus via endocytosis/macropinocytosis/actin and Rho-GTPase dependent manner; 3, 4 Transport of the virus through the vesicular trafficking pathway and escape of virus from endosome; 5 Translocation of the virus from the cytoplasm to the nucleus along microtubular track (MT)/without microtubular track. Translocation may involve interaction of virus with NPM1; 6 Disassembly of nucleocapsid by serine protease under acidic or neutral pH and entry of viral genome into the nucleus; 7 Conversion of viral ssDNA into dsDNA by host enzymes; 8, 9, 10 Transcription, translation and synthesis of Cap, Rep, and Rep′ proteins; 11, 12 Transport of Cap (through interaction with NPM1), Rep and Rep′ proteins from cytoplasm into the nucleus; 13 Rolling circular replication of dsDNA by viral Rep, Rep′, and host DNA polymerase; 14, 15 Genome packaging, capsid assembly and generation of new viral particle; 16 Transport of new virus from nucleus to cytoplasm; 17 Export of new virus. Question mark (6) indicates whether or not capsid disassembly occurs prior to the nuclear entry of the virus. Colored shapes represent…