Data from: Diel patterning in the bacterial community associated with the sea anemone Nematostella vectensis

Microbes can play an important role in the physiology of animals by
providing essential nutrients, inducing immune pathways, and influencing
the specific species that compose the microbiome through competitive or
facilitatory interactions. The community of microbes associated with
animals can be dynamic depending on the local environment, and factors
that influence the composition of the microbiome are essential to our
understanding of how microbes may influence the biology of their animal
hosts. Regularly repeated changes in the environment, such as diel
lighting, can result in two different organismal responses: a direct
response to the presence and absence of exogenous light and endogenous
rhythms resulting from a molecular circadian clock, both of which can
influence the associated microbiota. Here, we report how diel lighting and
a potential circadian clock impacts the diversity and relative abundance
of bacteria in the model cnidarian Nematostella vectensis using an
amplicon-based sequencing approach. Comparisons of bacterial communities
associated with anemones cultured in constant darkness and in light:dark
conditions revealed that individuals entrained in the dark had a more
diverse microbiota. Overall community composition showed little variation
over a 24-hour period in either treatment; however, abundances of
individual bacterial OTUs showed significant cycling in each treatment. A
comparative analysis of genes involved in the innate immune system of
cnidarians showed differential expression between lighting conditions in
N. vectensis, with significant up-regulation during long-term darkness for
a subset of genes. Together, our studies support a hypothesis that the
bacterial community associated with this species is relatively stable
under diel light conditions when compared with static conditions and that
particular bacterial members may have time-dependent abundance that
coincides with the diel photoperiod in an otherwise stable community.