Origin of reovirus oligo(A)

Area of Science:

• Virology
• Molecular Biology

Background:

• Reovirus virions contain double-stranded RNA genomes and approximately 1,200 molecules of oligo(A) per virion.
• Oligo(A) is a short chain of adenine nucleotides, 10-15 nucleotides in length.

Purpose of the Study:

• To investigate the role of oligo(A) in reovirus infectivity and replication.
• To determine if oligo(A) is a virus-specific product and its necessity for viral processes.

Main Methods:

• Purification of reovirus virions from infected cells (BHK, HeLa, L cells).
• Chymotryptic digestion to convert virions to cores.
• Assessing oligo(A) content and infectivity of virions and cores.
• Restoring infectivity of cores by adsorption to cells with Kaopectate.

Main Results:

• Oligo(A) was found in similar amounts and composition across different cell types, suggesting it's virus-specific.
• Conversion of virions to cores led to significant loss of oligo(A) and decreased infectivity.
• Partial restoration of infectivity was achieved by adsorbing cores to cells with Kaopectate.
• Re-purified virions from core-infected cells contained normal oligo(A) levels.

Conclusions:

• Oligo(A) is a virus-specific component of reovirus virions.
• Oligo(A) is not essential for reovirus infectivity.
• Oligo(A) is not required as a primer or template for its own synthesis during reovirus replication.