Now what happens inside signed Eukaryotic cells is when transcription takes place we form a pre mRNA molecule that contains introns and exons. But then what happens inside the Eukaryotic cell is we have a process that takes place that removes those intros from the mRNA to form an mRNA molecule that only consists of the exons. And this is a fully functional mRNA molecule that can now be used to form proteins. So if we are to use bacterial cells to form different types of eukaryotic proteins from Eukaryotic genes we have to first remove these introns from the genes of those Eukaryotic DNA molecules. So once again Eukaryotic genes contain noncoding segments called introns. And when Eukaryotic genes are transcribed the pre mRNA molecule that is formed contains those intron segments.