Naslov
The Ancestral Mitotic State: Closed Orthomitosis With Intranuclear Spindles in the Syncytial Last Eukaryotic Common Ancestor

Autori
Bremer, Nico ; Tria, Fernando D. K. ; Skejo, Josip ; Martin, William F.

Izvornik
Genome biology and evolution (1759-6653) 15 (2023), 3; Evad016, 13

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
last eukaryotic common ancestor, ancestral state reconstruction, mitosis, syncytium, eukaryogenesis

Sažetak
All eukaryotes have linear chromosomes that are distributed to daughter nuclei during mitotic division, but the ancestral state of nuclear division in the last eukaryotic common ancestor (LECA) is so far unresolved. To address this issue, we have employed ancestral state reconstructions for mitotic states that can be found across the eukaryotic tree concerning the intactness of the nuclear envelope during mitosis (open or closed), the position of spindles (intranuclear or extranuclear), and the symmetry of spindles being either axial (orthomitosis) or bilateral (pleuromitosis). The data indicate that the LECA possessed closed orthomitosis with intranuclear spindles. Our reconstruction is compatible with recent findings indicating a syncytial state of the LECA, because it decouples three main processes: chromosome division, chromosome partitioning, and cell division (cytokinesis). The possession of closed mitosis using intranuclear spindles adds to the number of cellular traits that can now be attributed to LECA, providing insights into the lifestyle of this otherwise elusive biological entity at the origin of eukaryotic cells. Closed mitosis in a syncytial eukaryotic common ancestor would buffer mutations arising at the origin of mitotic division by allowing nuclei with viable chromosome sets to complement defective nuclei via mRNA in the cytosol.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

Napomena
This project has received funding from the
European Research Council (ERC) under the European
Union's Horizon 2020 research and innovation
program (grant 666053 and 101018894) and the
Volkswagen Foundation (grant 93046) and the Moore
Simons Initiative on the Origin of the Eukaryotic
Cell (grant 9743).

POVEZANOST RADA