Ultrastructural morphogenesis of salmonid alphavirus 1

• Published in: Journal of Fish Diseases
• Main Authors: Herath, Tharangani, Ferguson, Hugh, Thompson, Kimberly, Adams, Alexandra, Richards, Randolph
• Other Authors: Institute of Aquaculture
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Blackwell 2012
• Subjects: Atlantic salmon; CHSE-214; electron microscopy; morphogenesis; salmonid alphavirus; ultrastructure; Atlantic salmon Diseases; Sav’
• Online Access: http://hdl.handle.net/1893/15449; https://doi.org/10.1111/j.1365-2761.2012.01420.x; http://dspace.stir.ac.uk/bitstream/1893/15449/1/journal%20of%20fish%20diseases%202012.pdf

Studies on the ultrastructural morphogenesis of viruses give an insight into how the host cell mechanisms are utilized for new virion synthesis. A time course examining salmonid alphavirus 1 (SAV 1) assembly was performed by culturing the virus on Chinook salmon embryo cells (CHSE-214). Different stages of viral replication were observed under electron microscopy. Virus-like particles were observed inside membrane-bound vesicles as early as 1 h following contact of the virus with the cells. Membrane-dependent replication complexes were observed in the cytoplasm of the cells, with spherules found at the periphery of late endosome-like vacuoles. The use of intracellular membranes for RNA replication is similar to other positive-sense single-stranded RNA (+ssRNA) viruses. The number of Golgi apparatus and associated vacuoles characterized by ‘fuzzy'-coated membranes was greater in virus-infected cells. The mature enveloped virions started to bud out from the cells at approximately 24 h post-infection. These observations suggest that the pathway used by SAV 1 for the generation of new virus particles in vitro is comparable to viral replication observed with mammalian alphaviruses but with some interesting differences.