In vivo transcriptional products of the chloroplast DNA of Euglena gracilis.

Cloned chloroplast restriction endonuclease DNA fragments were used as hybridization probes to identify the in vivo transcriptional products of the chloroplast genome from the alga Euglena gracilis. Total cellular RNA was size fractionated by electrophoresis in denaturing gels and transferred to nitrocellulose paper. Individual plasmids containing specific chloroplast DNA fragments were radioactively labeled in vitro and hybridized to the immobilized RNA. The stable RNAs in the chloroplast were identified on the basis of their size and their origin on the chloroplast genome. Several transcripts were shown to be developmentally expressed. Some transcripts showed a possible precursor-product relationship. The rDNA was shown to be transcribed as a large transcript and then processed to the, mature rRNAs.