George Beadle
The coding regions of the gene are separated by non-coding DNA that is not involved in protein expression. The non-coding regions, the introns, are cut from the precursor mRNAs in a process called "splicing". The split gene structure was found to be common to most eukaryotic genes. For this reason, one gene–one enzyme does not hold in the simple way put forward by Beadle and Tatum. This is because