How do viruses affect gene expression?

Viruses can affect gene expression by altering the transcription and translation processes within host cells.

When a virus infects a host cell, it hijacks the cell's machinery to replicate its own genetic material. This often involves the virus inserting its DNA or RNA into the host cell's genome, which can disrupt normal gene expression patterns. Viruses can also produce proteins that interfere with the host cell's transcription factors, which are responsible for regulating gene expression.

In some cases, viruses can activate or repress specific genes within the host cell. For example, the human papillomavirus (HPV) can activate genes that promote cell growth and division, leading to the development of cancer. Similarly, the hepatitis B virus can repress genes involved in immune system function, allowing the virus to evade detection and continue replicating within the host.

Overall, viruses can have a significant impact on gene expression within host cells. Understanding these mechanisms is important for developing effective treatments and vaccines for viral infections.