<i>Ixodes scapularis</i> tick–<i>A</i>. <i>phagocytophilum</i> coevolution.

<p>The pathogen inhibits apoptosis by reducing porin levels to increase infection but without affecting tick feeding and reproduction, as illustrated after gene knockdown to maintain tick vector capacity. However, the pathogens do not manipulate subolesin levels because, as shown after gene knockdown, it can affect infection and tick performance. These results illustrate coevolutionary mechanisms by which pathogens manipulate tick protective responses to facilitate infection while preserving tick feeding and vector capacity to guarantee survival of both pathogens and ticks.