Supplementary datasets for: Large-scale genome sequencing reveals the driving forces of viruses in microalgal evolution

Microalgae are integral primary producers for global ecosystems whose
genomes can be mined for ecological insights, but representative genome
sequences are lacking for many phyla. We cultured and sequenced 107
microalgae species from 11 different phyla indigenous to varied
geographies and climates. This genome collection was used to resolve
genomic differences between saltwater and freshwater microalgae.
Freshwater species showed domain-centric ontology enrichment for nuclear
and nuclear membrane functions, while saltwater species were enriched in
organellar and cellular membrane functions. Marine species contained
significantly more viral families in their genomes (p-value = 8 x 10(-4)).
Viral sequences were identified from Chlorovirus, Coccolithovirus,
Pandoravirus, Marseillevirus, Tupanvirus, and others integrated into algal
genomes. Algal, viral-origin sequences were found to be expressed and to
code for a wide variety of functions. Our results clarify the poorly
characterized occurrences of viral elements in algal genomes and define a
unified adaptive strategy for algal halotolerance.