Do RNA viruses follow the central dogma, or are their genes and proteins stored, transmitted, regulated, expressed and processed, differently from eukaryotes?
RNA viruses do not completely follow the central dogma of molecular biology, which states that genetic information flows from DNA to RNA to protein. This is because RNA viruses have an RNA genome instead of DNA. However, they still store genetic information, produce proteins, and replicate themselves, but the processes are somewhat different from eukaryotes.
In RNA viruses, the viral genome is composed of RNA instead of DNA. This RNA can either be single-stranded or double-stranded, and it carries the instructions needed for viral replication. When an RNA virus infects a host cell, it uses the host's cellular machinery to replicate its genetic material and produce viral proteins.
To replicate, RNA viruses first need to convert their RNA genome into DNA. This process is carried out by an enzyme called reverse transcriptase, which synthesizes a complementary DNA (cDNA) copy of the viral RNA. This cDNA can integrate into the host's genome or exist independently in the host cell. Once the cDNA is synthesized, it can be used as a template for producing viral RNA and viral proteins.
The production of viral proteins in RNA viruses is similar to that of eukaryotes, but there are some differences. In eukaryotes, the genetic information stored in DNA is transcribed into messenger RNA (mRNA), which is then translated into proteins by ribosomes. In RNA viruses, this process is more direct. The viral RNA genome itself acts as mRNA and is directly translated into viral proteins by the host cell's ribosomes.
Overall, while the basic principles of genetic information storage and protein production are similar, RNA viruses have unique ways of carrying out these processes due to their RNA genome.