Question

Do bacteria and archaea have introns and pseudogenes? Or just eukaryotes?

Answer 1

INTRONS

In some genes, not all the DNA portions are converted into mRNA or protein. Introns are the non-coding sequence of the RNA transcripts (present in the gene) which are removed or spliced out before translation process happens. This happens mainly in eukaryotes as they have a separate compartment called the nucleus which is the center place of replication and transcription of DNA sequences. The pre-mRNA formed as a result of transcription will undergo a process called splicing during which the non-coding sequences or the introns are removed and only the exons are contained. This is called mature mRNA.

Prokaryotes do not have a separate nucleus and all the replicated DNA are converted to RNA and eventually to proteins. Thus they do not possess introns.

It is said that the archaeal kingdom of organisms also have introns and studies are going on to reveal the very many introns present in them. But the splicing process is not yet known.

PSEUDOGENES

It is reported that many prokaryotes have pseudogenes in their genome. But in the case of archaea, pseudogenes are still present but due to gene decay through evolution, the number of pseudogenes are consistently decreasing. It is studied that there is a chance of presence of pseudogenes 1-5% in their genome.