Polycistronic/Monocistronic vs RNA Splicing

[sanguinee]

I understand that prokaryotic mRNA typically includes several genes in a single transcript (polycistronic), whereas eukaryotic mRNA includes only one gene per transcript (monocistronic). But RNA splicing kind of confuses me - because isn't that a way for one mRNA transcript to be spliced and create other products? Wouldn't that make eukaryotic mRNA polycistronic?

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[Hailstorm]

There are slightly different forms of genes: isoforms, as opposed to completely different genes.

 

[sanguinee]

So polycistronic refers to completely different genes, while RNA-splicing produces slightly different forms of genes?

 

[erythrocyte666]

polycistronic means once you have a synthesized mRNA, it'll look something like this: 5'----[Gene for protein A]----[Gene for protein B]----3' (think of the prokaryotic operon - you always see the necessary genes all side-by-side after the promoter/operator and these are all transcribed at once rather than separately)
viral genes are highly polycistronic, so gene for protein B can possibly start within the gene region for protein A
monocistronic means the mature (i.e. translatable) mRNA will code for a single protein - alternative splicing occurs in premature mRNA
i guess this is more a difference in terminology