Data from: Diverse hosts, diverse immune systems: evolutionary variation in bat immunology

The ability of multiple bat species to host zoonotic pathogens without
often showing disease has fostered growing interest in bat immunology,
indicating ways immune systems may differ between bats and other
vertebrates. However, interspecific variation in immunological diversity
among bats has only begun to be recognized. The order Chiroptera accounts
for over 20% of all mammal species and shows extreme diversity in a suite
of correlated ecological traits, such that bats should not be expected to
be immunologically homogenous. Here, we review the ecological and
evolutionary diversity of chiropteran hosts and highlight case studies
emphasizing the range of immune strategies thus far observed across bat
species, including responses to SARS-CoV-2. Next, we synthesize and
propose hypotheses to explain this immunological diversity, focused on
pathogen exposure, biogeography, host energetics, and environmental
stability. We then analyze immunology-related citations per species across
bats to motivate discussion of key research priorities. Broad sampling is
needed to remedy current biases, as only a fraction of bat species has
been immunologically studied. Such work should integrate methodological
advancements, in vitro and in vivo studies, and phylogenetic comparative
methods to robustly test evolutionary hypotheses and understand the
drivers and consequences of immunological diversity among bats.