In eukaryotes, RNA Polymerase III catalyses the synthesis of :

RNA polymerase III is responsible for transcription of tRNA, 5srRNA, and snRNAs (small nuclear RNAs). The RNA polymerase II transcribes precursor of mRNA, the heterogeneous nuclear RNA (hnRNA). The RNA polymerase I transcribes rRNAs (28S, 18S, and 5.8S).