We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Challenging the Importance of Plastid Genome Structure Conservation: New Insights From Euglenophytes.
- Authors
Maciszewski, Kacper; Fells, Alicja; Karnkowska, Anna
- Abstract
Plastids, similar to mitochondria, are organelles of endosymbiotic origin, which retained their vestigial genomes (ptDNA). Their unique architecture, commonly referred to as the quadripartite (four-part) structure, is considered to be strictly conserved; however, the bulk of our knowledge on their variability and evolutionary transformations comes from studies of the primary plastids of green algae and land plants. To broaden our perspective, we obtained seven new ptDNA sequences from freshwater species of photosynthetic euglenids—a group that obtained secondary plastids, known to have dynamically evolving genome structure, via endosymbiosis with a green alga. Our analyses have demonstrated that the evolutionary history of euglenid plastid genome structure is exceptionally convoluted, with a patchy distribution of inverted ribosomal operon (rDNA) repeats, as well as several independent acquisitions of tandemly repeated rDNA copies. Moreover, we have shown that inverted repeats in euglenid ptDNA do not share their genome-stabilizing property documented in chlorophytes. We hypothesize that the degeneration of the quadripartite structure of euglenid plastid genomes is connected to the group II intron expansion. These findings challenge the current global paradigms of plastid genome architecture evolution and underscore the often-underestimated divergence between the functionality of shared traits in primary and complex plastid organelles.
- Subjects
ORGANELLE formation; GENOMES; FRESHWATER algae; PLASTIDS; EUGLENOIDS; GREEN algae; ENDOSYMBIOSIS
- Publication
Molecular Biology & Evolution, 2022, Vol 39, Issue 12, p1
- ISSN
0737-4038
- Publication type
Article
- DOI
10.1093/molbev/msac255