Fig. 4

Identifying the ISS-associated-accessory genes of A. pittii. A A hierarchically clustered visualization of the A. pittii pangenome. Each column is a gene, and each row is a sample. The bottom rows indicate the proportions of ISS or Earth isolates in which a given gene was identified. The yellow box indicates the presence of genes particularly associated with the genomes of ISS strains. B, C The output of a gene-level association study comparing ISS and Earth strains. The volcano plot in B indicates the distribution of odds ratios between genes enriched in and lost in space flight. The top 30 most ISS-associated, non-hypothetical, distinct proteins with the highest odds ratios are labeled. Point color corresponds to the fraction of ISS genomes in which a gene is found. C The genomic context of significant, non-hypothetical, genes. The x-axis is the concatenation of all contigs in a representative ISS isolate. Blank spots on this axis contain genes or portions of the genome that were not evaluated in the association study due to the low prevalence