Assembly and Evolution of Poxviruses

Poxvirus assemblyPoxvirus assembly has been an intriguing area of research for several decades. While advancements in experimental techniques continue to yield fresh insights, many questions are still unresolved. Large genome sizes of up to 380 kbp, asymmetrical structure, an exterior lipid bilayer, and a cytoplasmic life cycle are some notable characteristics of these viruses. Inside the particle are two lateral bodiesLateral bodies and a protein wall-bound-biconcave coreCore containing the viral nucleocapsidNucleocapsid. The assembly progresses through five major stages—endoplasmic reticulum (ER) membrane alteration and rupture, crescentCrescent formation, immature virionImmature virion formation, genome encapsidationGenome encapsidation, virion maturationVirion maturation and in a subset of viruses, additional envelopment of the virion prior to its dissemination. Several large dsDNA viruses have been shown to follow a comparable sequence of events. In this chapter, we recapitulate our understanding of the poxvirus morphogenesisPoxvirus morphogenesis process while reviewing the most recent advances in the field. We also briefly discuss how virion assembly aids in our knowledge of the evolutionary links between poxviruses and other Nucleocytoplasmic Large DNA VirusesNucleocytoplasmic large DNA viruses (NCLDVs) (NCLDVs).