Quantifying the changes in genetic diversity within sequence-discrete bacterial populations across a spatial and...

Area of Science:

• Microbiology
• Environmental Science
• Genomics

Background:

• Recent studies show natural microbial communities are dominated by sequence-discrete populations.
• The stability of sequence and gene diversity within these populations, especially in dynamic freshwater (lotic) habitats, is not well understood.

Purpose of the Study:

• To quantify the dynamics of intra-population diversity in a riverine environment over two years.
• To investigate the relationship between intra-population diversity, population persistence, and gene-content stability.

Main Methods:

• Sampling across five sites in the Kalamas River over a two-year period.
• Quantification of intra-population sequence and gene-content diversity.
• Correlation analysis between diversity metrics and population persistence.

Main Results:

• A positive correlation was found between higher intra-population sequence diversity and longer population persistence.
• Most populations showed gene-content changes around 10%, with one exhibiting ~21% change, often involving hypothetical proteins and mobile elements.
• Seasonal variations in gene content, such as phototrophy-related proteins, were observed.

Conclusions:

• Freshwater microbial genomes exhibit remarkable dynamism across short temporal and spatial scales.
• Intra-population diversity influences population stability and has implications for defining bacterial species and microbial source tracking.