Retrovirus

Definition

A retrovirus is a type of virus that uses reverse transcription to convert its RNA genome into DNA after infecting a host cell. This unique ability allows the virus to integrate its genetic material into the host's genome, leading to a life cycle that can result in persistent infections. Retroviruses are known for their role in various diseases, particularly HIV/AIDS, which highlights their impact on human health.

5 Must Know Facts For Your Next Test

1. Retroviruses contain an RNA genome, which is different from many other viruses that have DNA genomes.
2. After entering a host cell, retroviruses use reverse transcriptase to create double-stranded DNA from their RNA.
3. The integrated viral DNA, known as a provirus, can remain inactive for years before being activated to produce new viral particles.
4. HIV is the most well-known retrovirus and primarily targets immune cells, leading to acquired immunodeficiency syndrome (AIDS).
5. Retroviral infections can lead to long-term health issues due to their ability to integrate into the host genome and evade the immune system.

Review Questions

• How does reverse transcription contribute to the life cycle of a retrovirus?
  • Reverse transcription is crucial in the life cycle of a retrovirus because it allows the virus to convert its RNA genome into DNA after entering a host cell. This newly formed viral DNA is then integrated into the host's genome, forming a provirus that can replicate whenever the host cell divides. This process enables the virus to persist in the host for extended periods, creating challenges for treatment and immune response.
• What implications does viral integration have for the long-term health of an infected individual?
  • Viral integration can have significant implications for an infected individual's long-term health. Once a retrovirus integrates its genetic material into the host's DNA, it can remain dormant or active depending on various factors. This persistent presence increases the risk of developing chronic diseases and can lead to conditions such as cancer or AIDS due to immune system compromise, as seen with HIV. Therefore, understanding viral integration is key for managing and treating retroviral infections.
• Evaluate the challenges that arise in treating retroviral infections like HIV due to their unique replication strategy.
  • Treating retroviral infections like HIV presents unique challenges largely due to their replication strategy involving reverse transcription and viral integration. The ability of retroviruses to integrate their genetic material into the host genome allows them to evade detection by the immune system and persist despite antiviral treatments. Additionally, mutations during reverse transcription can lead to drug resistance, making it difficult to develop effective therapies. Consequently, strategies like combination antiretroviral therapy (cART) are essential for managing these infections and preventing disease progression.

Related terms

Reverse Transcriptase: An enzyme used by retroviruses to convert their RNA into DNA, enabling the integration of viral genes into the host cell's DNA.

Viral Integration: The process by which a retrovirus inserts its genetic material into the host's genome, allowing it to replicate alongside the host's DNA.

Lysogenic Cycle: A phase of viral replication where the viral DNA integrates into the host genome and can remain dormant for a period, contrasting with the lytic cycle where the virus actively replicates and causes cell death.