Integration into host genome

Definition

Integration into host genome refers to the process by which certain viruses, particularly retroviruses, incorporate their genetic material into the DNA of the host cell. This integration allows the viral genome to be replicated alongside the host's DNA during cell division, leading to the production of new virus particles and potentially altering the host's genetic function.

5 Must Know Facts For Your Next Test

1. Integration typically occurs after reverse transcription, where viral RNA is converted into DNA before insertion into the host genome.
2. The enzyme integrase is crucial for facilitating the integration process, ensuring that the viral DNA is inserted at specific locations in the host's genome.
3. Once integrated, the viral genome can remain latent for long periods, leading to chronic infections that can reactivate under certain conditions.
4. Integration can disrupt normal gene function in the host, potentially leading to diseases such as cancer due to uncontrolled cell growth.
5. Different animal virus families exhibit varying mechanisms of integration; for example, retroviruses utilize a unique strategy involving their RNA genome.

Review Questions

• How does the process of integration into the host genome differ among various animal virus families?
  • Different animal virus families employ distinct mechanisms for integration into the host genome. Retroviruses specifically utilize reverse transcription to convert their RNA into DNA before integration. In contrast, other virus families may not integrate at all or may use different strategies such as episomal replication. This diversity in mechanisms can impact how viruses establish infections and interact with their hosts.
• Discuss the role of integrase in the integration process of retroviruses and its significance for viral replication.
  • Integrase is a vital enzyme for retroviruses that facilitates the integration of viral DNA into the host genome. It recognizes specific sequences on both the viral and host DNA, allowing for precise insertion. This step is crucial for viral replication because once integrated, the viral genome becomes a permanent part of the host's genetic material, enabling it to be replicated and transcribed during cell division. The activity of integrase can also influence how efficiently a virus can establish persistent infections.
• Evaluate the potential consequences of viral integration into the host genome and its implications for disease progression.
  • Viral integration into the host genome can have significant consequences, including disruption of normal cellular functions and potential oncogenesis. For example, if a virus integrates near or within an oncogene or tumor suppressor gene, it may lead to uncontrolled cell proliferation and cancer. Additionally, integrated viruses can create reservoirs for chronic infections, complicating treatment and increasing the risk of transmission. Understanding these implications is essential for developing effective antiviral strategies and managing diseases associated with viral infections.

Related terms

Retrovirus: A type of RNA virus that uses reverse transcription to convert its RNA into DNA, which can then integrate into the host genome.

Provirus: The form of the viral genome that is integrated into the host's DNA and can remain dormant until activated to produce new viruses.

Transcription: The process by which the integrated viral DNA is copied into RNA, which is necessary for the production of viral proteins and new virus particles.