Complex sentence: Of the three possible topological types, type I can be found in the genomes of prokaryotes, eukaryotes and RNA plant pathogens, whereas type II have been only described in prokaryotes and type III are mostly found in plants, plant pathogens and prokaryotes.
Split into simpler sentences: Of the three possible topological types, type I can be found in the genomes of prokaryotes, eukaryotes and RNA plant pathogens. Type II have been only described in prokaryotes, whereas type III are mostly found in plants, plant pathogens and prokaryotes.