do viruses have introns?

[premd]

Do viruses have introns? According to one question in the TPR, they do. However, I cannot find any source that states the same. Thanks!

---

Members don't see this ad.

 

[0Complications]

I am going to say no. I'm not 100% sure on this one, but I'm about 95% confident that they don't.

Are you sure they weren't talking about what was occurring to the hosts DNA?

 

[nlax30]

Looks like they can. I'm not really into virology but looks like judging from some PubMed abstracts..

High-risk human papillomaviruses (HPVs) encode two viral oncoproteins, E6 and E7, from a single bicistronic pre-mRNA containing three exons and two introns.

 

[Phlame217]

The can, but generally dont. The ones that tend to are ones like aids which implant a dna strand into the nucleus.

 

[Pansit]

Do viruses have introns? According to one question in the TPR, they do. However, I cannot find any source that states the same. Thanks!

Of course they can...Lysogenic viruses insert their DNA into the host cell...when the host cell transcribes the DNA, part of it could potentially be an intron and spliced out. Only bacterial DNA has no introns, as transcription and translation are simultaneous...

 

[pseudoknot]

The HIV primary transcript is alternatively spliced in many different ways.

 

[fashafosho]

Hi,
Viruses have introns and exons; they carry genomes in either DNA or RNA form and once in the host cell, they replicate or carry out transcription (which includes excision of introns) and then they subsequently use the host ribosomes to translate the mRNAs into proteins for viral assembly.

 

[armybound]

interesting question. as mentioned, it can happen. it's not too extremely common for there to be a pure intron that codes for nothing.

it's fairly common for there to be alternate splice sites, though. in my masters defense I was asked how viruses manage to pack so many genes into such a small genome and get around the fact that eukaryotes only have monocistronic transcripts. they have some pretty interesting tricks to get around that.

 

[tncekm]

In all honesty, I guess its "possible" that virus' have introns, however, it would make the most sense that in most cases virus' do not have introns. Here is why:

Virus' have a unique problem: they need to keep the size of their genome down because they're so small; so, generally their genome is really small. Because of the need to keep the genome small, the instance of introns in DNA virus' would have to be small.

 

[armybound]

I guess it depends how you describe an intron. there are intergenic stretches and there are splice variants where some AAs get taken out of a primary transcript, but there's no real rubbish areas.

look up HIV Rev's function for a good example of "introns"

 

[pseudoknot]

I guess it depends how you describe an intron. there are intergenic stretches and there are splice variants where some AAs get taken out of a primary transcript, but there's no real rubbish areas.

look up HIV Rev's function for a good example of "introns"

Nucleotides are removed from transcripts, not amino acids.

An intron could be defined as a sequence that is removed from a pre-mRNA transcript by the spliceosome. These are certainly present in both HIV and HSV, to use two examples. I don't know why we have people continuing to post in this thread with uninformed speculation when all this has already been covered.

 

[armybound]

Nucleotides are removed from transcripts, not amino acids.

An intron could be defined as a sequence that is removed from a pre-mRNA transcript by the spliceosome. These are certainly present in both HIV and HSV, to use two examples. I don't know why we have people continuing to post in this thread with uninformed speculation when all this has already been covered.

don't know what I was thinking there.. post translation instead of mRNA.