Data from: Experimental adaptation to singular pathogen challenge reduces susceptibility to novel pathogens in Drosophila melanogaster

In the wild, hosts often encounter and must respond to novel pathogens,
that is pathogens that they have not encountered in recent evolutionary
history, and therefore are not adapted to. How hosts respond to these
novel pathogens and the outcome of such infections can be shaped by the
host’s evolutionary history, especially by how well adapted the host is to
its native pathogens, that is pathogens they have evolved with. Host
adaptation to one pathogen can either increase its susceptibility to a
novel pathogen, due to specialization of immune defenses and trade-offs
between different arms of the immune system or can decrease susceptibility
to novel pathogens by virtue of cross-resistance. Using
laboratory Drosophila melanogaster populations, we explore if
hosts experimentally adapted to survive infection challenges by a
particular bacterial pathogen are also better at surviving infection
challenges by novel bacterial pathogens. We found that such hosts can
survive infection challenges by multiple novel pathogens, with the expanse
of cross-resistance determined by the identity of the native pathogen and
sex of the host. Therefore, we demonstrate that cross-resistance can
evolve in host populations by virtue of adaptation to a single pathogen.
This observation has important ecological consequences, especially in the
modern era where spillover of novel pathogens is a common occurrence due
to various factors, including climate change.