mikrovirukset

Mikrovirukset, also known as satellite viruses, are small, dependent viruses that require the presence of a helper virus to replicate. Unlike autonomous viruses, which can complete their life cycle independently, mikroviruses rely on the helper virus to provide essential proteins and other components necessary for their replication and assembly.

These viruses are typically composed of a single-stranded RNA genome, often ranging from 1 to 2 kilobases in length. Their genomes encode only a few proteins, usually one or two, which are crucial for their replication but insufficient for independent propagation. The helper virus, often a larger virus such as a plant virus, supplies the remaining proteins and enzymes required for the mikrovirus to replicate within the host cell.

Mikroviruses are commonly found in plants and are classified under the family *Mikroviridae*. They are known to infect a variety of plant species and can cause mild to severe symptoms, depending on the host plant and the specific mikrovirus involved. Symptoms may include stunting, chlorosis, mosaic patterns, and reduced yield.

The study of mikroviruses is important for understanding viral interactions and plant pathology. They serve as models for investigating how viruses manipulate host cells and how helper viruses influence the behavior of dependent viruses. Research in this area also contributes to the development of strategies for controlling viral diseases in agriculture.

Mikroviruses were first described in the 1970s, and since then, several species have been identified and characterized. Their unique dependency on helper viruses makes them distinct from other viral groups and highlights the complexity of viral ecosystems within host organisms.