Evidence that the 5' end of lac mRNA starts to decay as soon as it is synthesized

Abstract
By monitoring the decay of the first 16% of the beta-galactosidase message, we showed that the 5' end started to decay before the 3' end was completed and at a rate equivalent to that of the whole molecule. Thus, decay was neither from 3' to 5' nor from random internal fragmentation but rather proceeded in a net 5' to 3' direction.