The complete mitogenomes of the green algae Jenufa minuta and Jenufa perforata (Chlorophyceae, incertae sedis) reveal a variant genetic code previously unrecognized in the Chlorophyceae

Abstract

We sampled the first mitogenomes from a novel lineage of the Chlorophyceae that is sister to Sphaeropleales. Although the Jenufa perforata (27,180 bp) and Jenufa minuta (41,488 bp) mitogenomes differ markedly in size, gene order and intron content, their repertoires of conserved genes are essentially identical. Their rRNA genes display the same fragmentation patterns as their counterparts in Sphaeropleales. Their tRNA gene complements include two ancestral genes shared with Oedogoniales and Chaetophorales (Chlorophyceae) as well as a derived gene for a tRNA species decoding UGA as tryptophan. This noncanonical genetic code differs from those previously reported for Sphaeropleales.

Keywords

• chlorophyceae
• sphaeropleales
• fragmented rrna genes
• reduced gene content
• noncanonical genetic code