Complete plastid genome of Odontella aurita (Mediophyceae, Bacillariophyta) and plastid genome evolution in diatoms.

Abstract

Odontella aurita is an oblong shaped diatom with long spines and often forming chains. Odontella is one of ubiquitous marine planktonic group occurs from the temperate to arctic regions. The genus was subject to taxonomic and ecological studies, however, there is no organelles genome determined yet. In present study, we have collected the water sample from the Sihwaho (37˚1837.10N 126˚3619.0E the west coast of Korea) by using plankton net (10 um mash) than isolated Odontella aurita SH036. We have sequenced and annotated complete plastid genome (ptDNA) of the strain by using NGS technology. The ptDNA length is 120.3 kb with 31.9% of GC and a pair of inverted repeats (IR 2 X 7,725 bp). The circular ptDNA contains 167 genes, including 129 protein-coding genes, 6 rRNAs, and 30 tRNAs. The ptDNA of O. aurita was compared to that of Trieres chinensis [known as Odontella sinensis in NCBI under accession no. NC_001713 119.7 kb, 31.8% GC, a pair of IR (2 X 7,872 bp), and 128 protein-coding genes], the closely related species from all available diatoms data. Two ptDNAs showed significant size differences in 23 CDS and intergenic regions, and number of ORF. In order to understand the recent independent acquisiton of acpP gene in diatoms, we searched almost all homologous genes from available organisms, i.e. bacteria and eukaryotes. New ptDNA data may useful for better understanding on the genetic diversity and evolutidies, however, there is no organelles genome determined yet. In present study, we have collected the water sample from the Sihwaho (37˚1837.10N 126˚3619.0E the west coast of Korea) by using plankton net (10 um mash) than isolated Odontella aurita SH036. We have sequenced and annotated complete plastid genome (ptDNA) of the strain by using NGS technology. The ptDNA length is 120.3 kb with 31.9% of GC and a pair of inverted repeats (IR 2 X 7,725 bp). The circular ptDNA contains 167 genes, including 129 protein-coding genes, 6 rRNAs, and 30 tRNAs. The ptDNA of O. aurita was compared to that of Trieres chinensis [known as Odontella sinensis in NCBI under accession no. NC_001713 119.7 kb, 31.8% GC, a pair of IR (2 X 7,872 bp), and 128 protein-coding genes], the closely related species from all available diatoms data. Two ptDNAs showed significant size differences in 23 CDS and intergenic regions, and number of ORF. In order to understand the recent independent acquisiton of acpP gene in diatoms, we searched almost all homologous genes from available organisms, i.e. bacteria and eukaryotes. New ptDNA data may useful for better understanding on the genetic diversity and evoluti