Final answer:
Lentiviruses are more infectious than other retroviruses due to their ability to integrate efficiently into host genomes, high mutation rates during replication, and adaptability to host defenses. The presence of an ENV gene-encoded protein envelope also aids their infectivity.
Step-by-step explanation:
Lentiviruses are more infectious than other retroviruses because of their ability to infect both dividing and non-dividing cells and because they can integrate into the host genome more efficiently. Unlike most retroviruses, lentiviruses have a complex genome that can more easily adapt to the host's cellular environment. This adaptability is driven by high mutation rates during genome replication, as lentiviruses use reverse transcriptase, which is prone to making copying errors. Therefore, these mutations enable the lentivirus to evolve and bypass the host's immune defenses more effectively.
Retroviral DNA, in comparison to the genomes of RNA and DNA viruses, integrates into the host DNA, allowing a more stable presence within the host and increasing the chances of dissemination and persistence. The presence of an ENV gene-encoded protein envelope surrounding the retroviral DNA also facilitates the virus's entry into the cell and the subsequent integration.
The HIV virus, a type of lentivirus, is a pertinent example of a retrovirus that, due to its mutable nature and efficient infection mechanism, has a significant impact on human health. The damage to the infected cells caused by lentiviruses like HIV can disrupt normal cell functions and contribute to various diseases, including AIDS.