Abiotic selection of microbial genome size in the global ocean

David K. Ngugi, Silvia G. Acinas, Pablo Sánchez, Josep M. Gasol, Susana Agusti, David M. Karl, Carlos M. Duarte

Research output: Contribution to journalArticlepeer-review

11 Citations (Web of Science)


Strong purifying selection is considered a major evolutionary force behind small microbial genomes in the resource-poor photic ocean. However, very little is currently known about how the size of prokaryotic genomes evolves in the global ocean and whether patterns reflect shifts in resource availability in the epipelagic and relatively stable deep-sea environmental conditions. Using 364 marine microbial metagenomes, we investigate how the average genome size of uncultured planktonic prokaryotes varies across the tropical and polar oceans to the hadal realm. We find that genome size is highest in the perennially cold polar ocean, reflecting elongation of coding genes and gene dosage effects due to duplications in the interior ocean microbiome. Moreover, the rate of change in genome size due to temperature is 16-fold higher than with depth up to 200 m. Our results demonstrate how environmental factors can influence marine microbial genome size selection and ecological strategies of the microbiome.

Original languageEnglish
Article number1384
Number of pages12
JournalNature Communications
Issue number1
Publication statusPublished - 2023
Externally publishedYes


Dive into the research topics of 'Abiotic selection of microbial genome size in the global ocean'. Together they form a unique fingerprint.

Cite this