Hybrid-competition analyses were done to estimate the relatedness of 3H-labeled mRNA species synthesized during spore germination and log-phase growth. The competitions showed that early in the germination process 10--15 and 1--3% of the RNA transcribed from the H and from the L strand, respectively, were unique and absent during log-phase growth. At later stages, the amounts of the germination-specific H transcripts decreased more rapidly than the L transcripts. The competitions with pulse-labeled log-phase RNAs showed that vegetative genes were transcribed more rapidly from the H strand than from the L strand. Most of the results could be correlated with the observed decrease in the H/L asymmetry ration during spore germination.