Tripping on Acid: Trans-Kingdom Perspectives on Biological Acids in Immunity and Pathogenesis
Figure 3
Phylogeny of acidic phagolysosome use in immunity.
Simplified phylogeny of life, marking major hypothesized steps supported by current comparative biology in the co-opting of the acidic phagolysosome system in innate and adaptive immunity (blue). Sister taxon names are illustrative and not necessarily of same phylogenetic rank, and genetic distances are not to scale. All life has innate immunity, but only vertebrates have adaptive immunity (red). Origins of key proteins that regulate the system are shown in green.