Complete Mitogenome Sequencing, Annotation, and Phylogeny of , a Red Alga with Intronic Gene.

The mitochondrial genome (mitogenome) is essential for identifying species and tracing genetic variation, gene patterns, and evolutionary studies. Here, the mitogenome of was sequenced on the Illumina sequencing platform. This circular mitogenome (28,265 bp) contains 49 genes, including three rRNAs, twenty transfer RNAs (tRNAs), and twenty-six protein-coding genes (PCGs). Nucleotide composition indicates biased AT (68.8%) content. A Group II intronic sequence was identified between two exons of the gene, and this sequence comprises an open reading frame (ORF) that encodes a hypothetical protein. The gene content, annotation, and genetic makeup are identical to those of Halymeniaceae members. The complete mitogenome sequences of the and species were used in a phylogenetic analysis, which revealed that these two genera are monophyletic and that and are closely related. This newly constructed mitogenome will help us better understand the general trends in the development of introns in Halymeniaceae, as well as the evolution of red algal mitogenomes within the Rhodophyta and among diverse algal species.