Complete mitochondrial genome of the harmful algal bloom species Thalassiosira nordenskioeldii (Mediophyceae, Bacillariophyta) from the east China sea

Thalassiosira nordenskioeldii is a common harmful algal bloom (HAB) species with worldwide distribution. Although barcode sequences of this ecologically important species have been published, no genome data have been published for T. nordenskioeldii. In this study, we constructed the complete mitochondrial genome (mtDNA) of a T. nordenskioeldii strain isolated from the East China Sea. The T. nordenskioeldii mtDNA is circular and has a length of 47,038 bp and a GC content of 30.84%. The mtDNA encodes 69 genes, including 40 protein-coding (PCGs), 27 tRNA and two rRNA genes. Phylogenetic analysis using concatenated amino acid sequences of 31 shared PCGs from 37 diatom mtDNAs revealed that the mtDNA of T. nordenskioeldii was fully resolved in a clade with that of Thalassiosira profunda. The mtDNA of T. nordenskioeldii showed high collinearity with those of T. profunda and Skeletonema marinoi with only minor rearrangements. The completion of Thalassiosira mtDNAs will facilitate evolutionary studies on species of the order Thalassiosirales and the class Mediophyceae.