Extensive chloroplast genome rearrangement amongst three closely related Halamphora spp. (Bacillariophyceae), and evidence for rapid evolution as compared to land plants

• DOI: 10.1371/journal.pone.0217824
• Publication Date: 2019-07-03T17:27:32Z
• Authors: Sarah E. Hamsher; Kyle G. Keepers; Cloe S. Pogoda; Joshua G. Stepanek; Nolan C. Kane; J. Patrick Kociolek
• Keywords: Lineage (genetic); Genome size

Diatoms are the most diverse lineage of algae, but diversity their chloroplast genomes, particularly within a genus, has not been well documented. Herein, we present three genomes from genus Halamphora (H. americana, H. calidilacuna, and coffeaeformis), first pennate diatom to be represented by more than one species. ranged in size ~120 150 kb, representing 24% difference genus. Differences genome were due changes length inverted repeat region, intergenic regions, variable presence ORFs that appear encode as-yet-undescribed proteins. All species shared set 161 core features differed two genes, serC tyrC foreign unknown origin, respectively. A comparison these data previously published non-pennate Cyclotella (Thalassiosirales) revealed undergone extensive rearrangement compared other genera, as containing variation Finally, those land plants indicates this may evolving at least ~4-7 times faster plants. Studies such provide deeper insights into evolution important genetic resources for future analyses.