Characterisation of pouch secretions from breeding Tasmanian devils

Tasmanian devils (Sarcophilus harrisii), like all marsupials, give birth to altricial young. Here we employ proteomic analysis to identify components of devil pouch secretions (red oil) that may contribute to offspring survival and development. Proteins were extracted from 5 samples and analysed by liquid chromatography-tandem mass spectrometry. Peptide-level evidence revealed proteins involved in a diverse set of immune pathways, including those mediating iron-ion transport, defence responses to bacteria, innate immune responses, and antigen processing. A core set of 200 proteins was identified across at least three samples, 63 of which were associated with antimicrobial or immunoregulatory functions. These included immunoglobulins, components of complement and coagulation cascade, and antimicrobial proteins and peptides. For the first time, these findings highlight the Tasmanian devils red oil secretions as a source of immune proteins likely contributing to microbiome restructuring during lactation. Moreover, the data indicate that these proteins may act synergistically in pathways triggered by immune challenges or physiological stress. In briefMicrobial shifts in the Tasmanian devil pouch are critical for establishing a protective environment for the developing joey. This study confirms that Tasmanian devil red oil contains a diverse array of immune proteins that likely contribute to these microbial shifts.