Single-cell genomics unveils a canonical origin of the diverse mitochondrial genomes of euglenozoans
department or school: Science, Faculty of
department or school: Non UBC
department or school: Botany, Department of
data provider: DSpace
identifier citation: BMC Biology. 2021 May 17;19(1):103
rights copyright: The Author(s)
creator: Záhonová, Kristína
creator: Lax, Gordon
creator: Sinha, Savar D
creator: Leonard, Guy
creator: Richards, Thomas A
creator: Lukeš, Julius
creator: Wideman, Jeremy G
issued: 2021-05-19T18:06:48Z
issued: 2021-05-17
description: 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) of euglenids comprise multiple linear chromosomes carrying single genes, whereas mitochondrial chromosomes are circular non-catenated in diplonemids, but circular and catenated in kinetoplastids. In diplonemids and kinetoplastids, mitochondrial mRNAs require extensive and diverse editing and/or trans-splicing to produce mature transcripts. All known euglenozoan mtDNAs exhibit extremely short mitochondrial small (rns) and large (rnl) subunit rRNA genes, and absence of tRNA genes. How these features evolved from an ancestral bacteria-like circular mitochondrial genome remains unanswered. Results: We sequenced and assembled 20 euglenozoan single-cell amplified genomes (SAGs). In our phylogenetic and phylogenomic analyses, three SAGs were placed within kinetoplastids, 14 within diplonemids, one (EU2) within euglenids, and two SAGs with nearly identical small subunit rRNA gene (18S) sequences (EU17/18) branched as either a basal lineage of euglenids, or as a sister to all euglenozoans. Near-complete mitochondrial genomes were identified in EU2 and EU17/18. Surprisingly, both EU2 and EU17/18 mitochondrial contigs contained multiple genes and one tRNA gene. Furthermore, EU17/18 mtDNA possessed several features unique among euglenozoans including full-length rns and rnl genes, six mitoribosomal genes, and nad11, all likely on a single chromosome. Conclusions: Our data strongly suggest that EU17/18 is an early-branching euglenozoan with numerous ancestral mitochondrial features. Collectively these data contribute to untangling the early evolution of euglenozoan mitochondria.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/78381
note: RESEARCH ARTICLE Open AccessSingle-cell genomics unveils a canonicalorigin of the diverse mitochondrialgenomes of euglenozoansKristína Záhonová1,2, Gordon Lax3, Savar D. Sinha4, Guy Leonard5, Thomas A. Richards5, Julius Lukeš1,6* andJeremy G. Wideman4*AbstractBackground: The supergroup Euglenozoa unites heterotrophic flagellates from three major clades, kinetoplastids,diplonemids, and euglenids, each of which exhibits extremely divergent mitochondrial characteristics. Mitochondrialgenomes (mtDNAs) of euglenids comprise multiple linear chromosomes carrying single genes, whereasmitochondrial chromosomes are circular non-catenated in diplonemids, but circular and catenated in kinetoplastids.In diplonemids and kinetoplastids, mitochondrial mRNAs require extensive and diverse editing and/or trans-splicingto produce mature transcripts. All known euglenozoan mtDNAs exhibit extremely short mitochondrial small (rns)and large (rnl) subunit rRNA genes, and absence of tRNA genes. How these features evolved from an ancestralbacteria-like circular mitochondrial genome remains unanswered.Results: We sequenced and assembled 20 euglenozoan single-cell amplified genomes (SAGs). In our phylogeneticand phylogenomic analyses, three SAGs were placed within kinetoplastids, 14 within diplonemids, one (EU2) withineuglenids, and two SAGs with nearly identical small subunit rRNA gene (18S) sequences (EU17/18) branched aseither a basal lineage of euglenids, or as a sister to all euglenozoans. Near-complete mitochondrial genomes wereidentified in EU2 and EU17/18. Surprisingly, both EU2 and EU17/18 mitochondrial contigs contained multiple genesand one tRNA gene. Furthermore, EU17/18 mtDNA possessed several features unique among euglenozoansincluding full-length rns and rnl genes, six mitoribosomal genes, and nad11, all likely on a single chromosome.Conclusions: Our data strongly suggest that EU17/18 is an early-branching euglenozoan with numerous ancestralmitochondrial features. Collectively…
has type: Article
is shown at: 10.14288/1.0398045
language: eng
peer review status: Reviewed
provider: Vancouver : University of British Columbia Library
publisher: BioMed Central
publisher DOI: 10.1186/s12915-021-01035-y
rights: Attribution 4.0 International (CC BY 4.0)
rights URI: http://creativecommons.org/licenses/by/4.0/
scholar level: Faculty
subject: Single-cell amplified genome
subject: Evolution
subject: Mitochondrial ribosome
subject: Phylogeny
type: Text
identifier URI: http://hdl.handle.net/2429/78381