Data from: Population connectivity patterns of genetic diversity, immune responses and exposure to infectious pneumonia in a metapopulation of desert bighorn sheep

Habitat fragmentation is an important driver of biodiversity loss and can
be remediated through management actions aimed at maintenance of natural
connectivity in metapopulations. Connectivity may protect populations from
infectious diseases by preserving immunogenetic diversity and disease
resistance. However, connectivity could exacerbate the risk of infectious
disease spread across vulnerable populations. We tracked the spread of a
novel strain of Mycoplasma ovipneumoniae in a metapopulation of desert
bighorn sheep (Ovis canadensis nelsoni) in the Mojave desert to
investigate how variation in connectivity among populations influenced
disease outcomes. M. ovipneumoniae was detected throughout the
metapopulation, indicating that the relative isolation of many of these
populations did not protect them from pathogen invasion. However, we show
that connectivity among bighorn sheep populations was correlated with
higher immunogenetic diversity, a protective immune response and lower
disease prevalence. Variation in protective immunity predicted infection
risk in individual bighorn sheep and was associated with heterozygosity at
genetic loci linked to adaptive and innate immune signalling. Together,
these findings may indicate that population connectivity maintains
immunogenetic diversity in bighorn sheep populations in this system and
has direct effects on immune responses in individual bighorn sheep and
their susceptibility to infection by a deadly pathogen. Our study suggests
that the genetic benefits of population connectivity could outweigh the
risk of infectious disease spread and supports conservation management
that maintains natural connectivity in metapopulations.