Related Experiment Video
Updated: May 3, 2026

Discrimintion and Mapping of the Primary and Processed Transcripts in Maize Mitochondrion Using a Circular RT-PCR-based Strategy
Published on: July 29, 2019
A small portion of plastid transcripts is polyadenylated in the flagellate Euglena gracilis
Kristína Záhonová1, Lucia Hadariová2, Rostislav Vacula2
1Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic; Department of Genetics, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia.
Abstract:
Euglena gracilis possesses secondary plastids of green algal origin. In this study, E. gracilis expressed sequence tags (ESTs) derived from polyA-selected mRNA were searched and several ESTs corresponding to plastid genes were found. PCR experiments failed to detect SL sequence at the 5'-end of any of these transcripts, suggesting plastid origin of these polyadenylated molecules. Quantitative PCR experiments confirmed that polyadenylation of transcripts occurs in the Euglena plastids. Such transcripts have been previously observed in primary plastids of plants and algae as low-abundance intermediates of transcript degradation. Our results suggest that a similar mechanism exists in secondary plastids.
Related Concept Videos
Diversity of Protists I
Export of Mitochondrial and Chloroplast Genes
Pre-mRNA Processing: Modification of pre-mRNA Ends
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
pre-mRNA Processing
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl...
Protein Transport to the Outer Chloroplast Membrane
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Non-nuclear Inheritance

