Spliceosome

A spliceosome is an enzyme involved in the process of transcription.  Because DNA contains a large amount of non-coding information (introns). when mRNA is transcrived it also contains non-coding information.  This is of no use to the mRNA as the non-coding information does not need to be transcribed.  The splicesome is the enzyme that splices the introns out of pre-mRNA to give the final mRNA product ready for translation.