Introns mediate post-transcriptional enhancement of nuclear gene expression in the green microalga Chlamydomonas reinhardtii

Autoři: Thomas Baier aff001;  Nick Jacobebbinghaus aff001;  Alexander Einhaus aff001;  Kyle J. Lauersen aff001;  Olaf Kruse aff001
Působiště autorů: Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universitätsstrasse, Bielefeld, Germany aff001;  Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia aff002
Vyšlo v časopise: Introns mediate post-transcriptional enhancement of nuclear gene expression in the green microalga Chlamydomonas reinhardtii. PLoS Genet 16(7): e32767. doi:10.1371/journal.pgen.1008944
Kategorie: Research Article
doi: 10.1371/journal.pgen.1008944


Efficient nuclear transgene expression in the green microalga Chlamydomonas reinhardtii is generally hindered by low transcription rates. Introns can increase transcript abundance by a process called Intron-Mediated Enhancement (IME) in this alga and has been broadly observed in other eukaryotes. However, the mechanisms of IME in microalgae are poorly understood. Here, we identified 33 native introns from highly expressed genes in C. reinhardtii selected from transcriptome studies as well as 13 non-native introns. We investigated their IME capacities and probed the mechanism of action by modification of splice sites, internal sequence motifs, and position within transgenes. Several introns were found to elicit strong IME and found to be broadly applicable in different expression constructs. We determined that IME in C. reinhardtii exclusively occurs from introns within transcribed ORFs regardless of the promoter and is not induced by traditional enhancers of transcription. Our results elucidate some mechanistic details of IME in C. reinhardtii, which are similar to those observed in higher plants yet underly distinctly different induction processes. Our findings narrow the focus of targets responsible for algal IME and provides evidence that introns are underestimated regulators of C. reinhardtii nuclear gene expression.

Klíčová slova:

Algae – DNA transcription – Eukaryota – Gene expression – Chlamydomonas reinhardtii – Introns – Messenger RNA – Sequence motif analysis


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