Figure 8.

RNA Gel Blots Showing the Levels of Excised Introns in rnc1 Mutants.

Total leaf RNA (5 μg per lane) was analyzed by RNA gel blot hybridization using probes specific for the indicated intron. RNA from a caf1 mutant, which has a strong defect in petD splicing, was included on the petD intron blot for comparison. Arrows point to presumed excised introns: their sizes match those of excised introns and they do not hybridize to exon probes (data not shown). The reduced splicing of the rpl2 and rps12-int2 introns in the strong rnc1 alleles (rnc1-2/rnc1-3 and rnc1-2 homozygotes) is not informative because these introns are in subgroup IIA and fail to splice in all maize mutants lacking plastid ribosomes. iv, ivory leaves; pg, pale green leaves.