Polyomavirus genome and polyomavirus enhancer-driven gene expression during myogenesis.

Area of Science:

• Molecular Biology
• Cell Biology
• Virology

Background:

• Myogenic differentiation involves coordinated gene expression.
• Polyomavirus (Py) early mRNA is co-transcribed with myogenic function mRNAs.
• A common regulatory factor may control coordinate gene expression.

Purpose of the Study:

• Investigate the relationship between Py infection and myoblast differentiation.
• Identify regulatory mechanisms of coordinate gene expression.
• Examine the role of the Py enhancer in myogenic gene expression.

Main Methods:

• In vitro differentiation of mouse C2 myoblasts.
• Polyomavirus infection and resistance studies.
• Analysis of alpha-actin and myosin light-chain mRNA expression.
• Transfection with chimeric plasmids (pSVPy12CAT) for gene expression analysis.

Main Results:

• Py infection inhibits C2 myoblast differentiation and myogenic mRNA expression.
• Py-resistant myoblasts show dominant permissibility to Py growth and myogenic mRNA expression in hybrids.
• The Py enhancer-driven CAT gene is expressed in transfected C2 cells regardless of differentiation stage.
• Undifferentiated cells expressing the CAT gene restricted viral growth, while Py-resistant cells also expressed the CAT gene.

Conclusions:

• Py infection disrupts normal myoblast differentiation and gene expression.
• Viral and cellular regulatory factors interact during myogenesis.
• The Py enhancer's function may differ in transient transfections versus genomic integration.