Data for: Insect homolog of oxytocin/vasopressin associated with parenting of males but not females in a subsocial beetle

Parental care is thought to evolve through modification of behavioral
precursors, which predicts that the mechanistic changes occur in the genes
underlying those traits. The duplicated gene system of
oxytocin/vasopressin has been broadly co-opted across vertebrates to
influence parenting, from a pre-duplication ancestral role in water
balance. It remains unclear whether co-option of these genes for parenting
is limited to vertebrates. Here, we experimentally tested for associations
between inotocin gene expression and water balance, parental acceptance of
offspring, and active parenting in the subsocial beetle Nicrophorus
orbicollis, to test whether a single copy homologue, inotocin, has
similarly been co-opted for parental care in a species with elaborate
parenting. As expected, inotocin was associated with water balance in both
sexes. Inotocin expression increased around sexual maturation in both
males and females, although more clearly in males. Finally, we found that
expression of inotocin was not associated with acceptance of larvae but
was associated with a transition to male but not female parenting.
Moreover, level of offspring provisioning behavior and gene expression
were positively correlated in males but uncorrelated in females. Our
results suggest a broad co-option of this system for parenting that may
have existed prior to gene duplication, and that inotocin may be
associated with flexibility in parenting behavior.