Draft genomes of three closely related low light-adapted Prochlorococcus

Area of Science:

• Marine microbiology
• Genomics
• Oceanography

Background:

• Prochlorococcus is a key marine cyanobacterium in warm ocean ecosystems.
• It serves as a model organism for microbial evolution and ecology studies.
• Existing genomic data lacks representation of its full wild diversity, especially low light-adapted strains.

Purpose of the Study:

• To expand the genomic representation of Prochlorococcus diversity.
• To isolate and characterize low light-adapted Prochlorococcus strains.
• To provide new genomic resources for studying microbial evolution.

Main Methods:

• Isolation of Prochlorococcus strains from enrichment cultures.
• Whole-genome sequencing using Illumina paired reads.
• De novo assembly of draft genomes.
• Analysis of co-enriched heterotrophic marine bacteria.

Main Results:

• Three draft-quality Prochlorococcus genomes (P1344, P1361, P1363) were obtained from North Pacific samples.
• These genomes belong to the low light-adapted LLIV clade and are highly related (99.9% ANI).
• Gene content varies among these closely related genomes, offering insights into fine-scale variation.

Conclusions:

• The new genomes significantly expand the Prochlorococcus genomic toolkit.
• These resources facilitate the study of microevolutionary processes in marine cyanobacteria.
• The findings contribute to a better understanding of Prochlorococcus diversity and adaptation.