Metabolic trade-offs constrain the cell size ratio in a nitrogen-fixing symbiosis.
Cell
; 187(7): 1762-1768.e9, 2024 Mar 28.
Article
in En
| MEDLINE
| ID: mdl-38471501
ABSTRACT
Biological dinitrogen (N2) fixation is a key metabolic process exclusively performed by prokaryotes, some of which are symbiotic with eukaryotes. Species of the marine haptophyte algae Braarudosphaera bigelowii harbor the N2-fixing endosymbiotic cyanobacteria UCYN-A, which might be evolving organelle-like characteristics. We found that the size ratio between UCYN-A and their hosts is strikingly conserved across sublineages/species, which is consistent with the size relationships of organelles in this symbiosis and other species. Metabolic modeling showed that this size relationship maximizes the coordinated growth rate based on trade-offs between resource acquisition and exchange. Our findings show that the size relationships of N2-fixing endosymbionts and organelles in unicellular eukaryotes are constrained by predictable metabolic underpinnings and that UCYN-A is, in many regards, functioning like a hypothetical N2-fixing organelle (or nitroplast).
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cyanobacteria
/
Haptophyta
/
Nitrogen Fixation
Language:
En
Journal:
Cell
Year:
2024
Type:
Article