Single-cell genomics unveils a canonical origin of the diverse mitochondrial genomes of euglenozoans.

摘要: Background The supergroup Euglenozoa unites heterotrophic flagellates from three major clades, kinetoplastids, diplonemids, and euglenids, each of which exhibits extremely divergent mitochondrial characteristics. Mitochondrial genomes (mtDNAs) euglenids comprise multiple linear chromosomes carrying single genes, whereas are circular non-catenated in but catenated kinetoplastids. In diplonemids mRNAs require extensive diverse editing and/or trans-splicing to produce mature transcripts. All known euglenozoan mtDNAs exhibit short small (rns) large (rnl) subunit rRNA absence tRNA genes. How these features evolved an ancestral bacteria-like genome remains unanswered. Results We sequenced assembled 20 single-cell amplified (SAGs). our phylogenetic phylogenomic analyses, SAGs were placed within 14 one (EU2) two with nearly identical gene (18S) sequences (EU17/18) branched as either a basal lineage or sister all euglenozoans. Near-complete identified EU2 EU17/18. Surprisingly, both EU17/18 contigs contained genes gene. Furthermore, mtDNA possessed several unique among euglenozoans including full-length rns rnl six mitoribosomal nad11, likely on chromosome. Conclusions Our data strongly suggest that is early-branching numerous features. Collectively contribute untangling the early evolution mitochondria.