A Molecular Study of Microbe Transfer between Distant Environments
Distributions of GC3s for each of 1216 ORF pairs with closer similarity in the foreign environment. Using GC3s% = 48% as a separator (dotted lines), the ORF pairs are classified based on the GC content of its two members. Category A (upper right) is the quadrant where we expect to find possible transfer events from soil to sea, since these pairs have high GC3%s values for both members. Pairs in category B (lower left) have low GC3%s scores for both Genes, which could suggest a transfer from a sea-like environment to soil. Category C (lower right) has typical GC3s% values for both members of ORF pairs. These pairs are likely to be ancient conserved sequences. Finally, Category D (upper left) has atypical values for both Genes, close to the expected given the shape of the GC3% distribution (28 observed, 24 expected). Unsaturated Ks values are green, and pairs with Kn/Ks>1 are red.