Effect of Parental Care on the Verical Transmission of Enteric Bacteria in Nicrophorus Defodiens

Parental care has evolved promote fitness gains. Burying beetles engage in extensive pre- hatching and post-hatching parental care providing several avenues to transmit bacteria to their offspring. One aspect of pre-hatching parental care consists of preserving a small vertebrate carcass via oral and anal secretions, allowing the carcass to be used as a reproductive resource. Post-hatching parental care consists in large part of parental regurgitations of the preserved carcass. We sought to determine if pre-hatching parental care resulted in bacterial transmission from adults to carcasses via anal secretions. We then sought to determine if lab-rearing conditions affected the digestive tract bacterial communities of F1 and F2 generation adults. We finally sought to determine if carcasses and post-hatching parental care in the form of parental regurgitations resulted into bacterial transmission to larvae. Using High-Throughput Illumina MiSeq, we were able to characterize bacterial communities of adult and larval digestive tracts, anal secretions, and unprepared and prepared carcasses. Our results show that bacterial communities of adults are dissimilar from anal secretions and prepared carcasses. We then show that lab-rearing conditions do not significantly alter digestive tract bacterial communities of F1 and F2 generation adults relative to wild caught adults. We proceed to show that larvae receiving parental regurgitations have digestive tract bacterial communities similar to their parents whereas larvae that do not receive parental regurgitations have dissimilar digestive tract bacterial communities from their parents. We further show that bacterial communities of prepared carcasses are dissimilar from all larvae. Our evidence suggests that anal secretions to preserve carcasses for the reproductive bout and have no influence on bacterial transmission to neither carcasses nor larvae. Our evidence also suggests that parental regurgitations influence bacterial transmission to offspring.