A novel fingerprint method for analyzing the expression of complex multigene families of very low transcript abundance.

A novel RNA fingerprint method has been developed based on the polymerase chain reaction to identify individual mRNA species derived from different members of a complex multigene family of very low transcript abundance. Using this method, changes in the composition of complex thionin mRNA populations and in the appearance of individual thionin mRNA species in different organs and in response to external stimuli were detected in Hordeum murinum. A single nucleotide exchange within the transcribed DNA may be sufficient to allow the distinction between otherwise identical transcripts.