Which vector has a unique advantage of integrating into chromosomes without disrupting the genome?

The adeno-associated virus (AAV) is known for its unique capability to integrate into the host genome in a manner that is less disruptive compared to other vectors, such as retroviruses. This property arises from its reliance on specific loci for integration, commonly at chromosome 19 in humans, which allows it to insert its genetic material in a precise location. This characteristic makes AAV particularly valuable for gene therapy applications, where stable and long-term expression of the therapeutic gene is required without causing unwanted mutations or disruptions to essential genes that could occur with other vectors.

In contrast, retroviruses integrate their genetic material into the host genome but can cause disruptions at the integration site, potentially leading to unintended consequences, such as insertional mutagenesis. Adenoviruses do not integrate into the host genome at all; instead, they exist as episomes, which can limit their use for long-term gene expression. Naked DNA, while capable of transient expression, lacks the ability to integrate into the genome entirely, limiting its utility for sustained genetic modification. Thus, the integration capacity of AAV, coupled with its minimal disruption to the host genome, distinguishes it as an ideal choice for therapeutic applications that require lasting genetic changes.