Integration of large and diverse angiosperm DNA fragments into Asian Gnetum mitogenomes.
BMC Biol
; 22(1): 140, 2024 Jun 25.
Article
em En
| MEDLINE
| ID: mdl-38915079
ABSTRACT
BACKGROUND:
Horizontal gene transfer (HGT) events have rarely been reported in gymnosperms. Gnetum is a gymnosperm genus comprising 25â35 species sympatric with angiosperms in West African, South American, and Southeast Asian rainforests. Only a single acquisition of an angiosperm mitochondrial intron has been documented to date in Asian Gnetum mitogenomes. We wanted to develop a more comprehensive understanding of frequency and fragment length distribution of such events as well as their evolutionary history in this genus.RESULTS:
We sequenced and assembled mitogenomes from five Asian Gnetum species. These genomes vary remarkably in size and foreign DNA content. We identified 15 mitochondrion-derived and five plastid-derived (MTPT) foreign genes. Our phylogenetic analyses strongly indicate that these foreign genes were transferred from diverse eudicots-mostly from the Rubiaceae genus Coptosapelta and ten genera of Malpighiales. This indicates that Asian Gnetum has experienced multiple independent HGT events. Patterns of sequence evolution strongly suggest DNA-mediated transfer between mitochondria as the primary mechanism giving rise to these HGT events. Most Asian Gnetum species are lianas and often entwined with sympatric angiosperms. We therefore propose that close apposition of Gnetum and angiosperm stems presents opportunities for interspecific cell-to-cell contact through friction and wounding, leading to HGT.CONCLUSIONS:
Our study reveals that multiple HGT events have resulted in massive amounts of angiosperm mitochondrial DNA integrated into Asian Gnetum mitogenomes. Gnetum and its neighboring angiosperms are often entwined with each other, possibly accounting for frequent HGT between these two phylogenetically remote lineages.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Filogenia
/
Transferência Genética Horizontal
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Gnetum
/
Genoma Mitocondrial
Idioma:
En
Revista:
BMC Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Taiwan