I think you'll find some of the tricks that (mostly) viruses use to be interesting. Take a look at ribosomal frameshifting [1], where the viral RNA has a specia

I think you'll find some of the tricks that (mostly) viruses use to be interesting. Take a look at ribosomal frameshifting [1], where the viral RNA has a special structure such that at a certain point during translation in the ribosome it will skip back 1 nucleotide (a -1 frameshift; -2 and +1 frameshifts have been observed as well, more rarely), thus changing the whole reading frame. Viruses use this to encode multiple protein products in a single strand of RNA, a sort of compression. But that's not all. Say that the amount of "0-frame" protein to "-1-frame" protein needs to be at a ratio of 20:1; then if the frameshift occurs with a probability of about 5% (i.e. 5% of the time that the viral RNA is translated), these protein products will then be produced in just the right ratio (this isn't a made up example either, see [2]). So not only does this trick allow for the RNA to be compressed, it also regulates protein expression. All with just one strand of RNA. [1] https://en.wikipedia.org/wiki/Ribosomal_frameshift https://en.wikipedia.org/wiki/Ribosomal_frameshift [2] https://en.wikipedia.org/wiki/HIV_ribosomal_frameshift_signal https://en.wikipedia.org/wiki/HIV_ribosomal_frameshift_signa...