Transcriptome sequencing of the long-nosed bandicoot (Perameles nasuta) reveals conservation and innovation of immune genes in the marsupial order Peramelemorphia

Katrina M. Morris, Haylee J. Weaver, Denis O’Meally, Marion Desclozeaux, Amber Gillett, Adam Polkinghorne

Bandicoots are omnivorous marsupials of the order Peramelemorphia. Conservation concerns and their unique biological characteristics suggest peramelomorphs are worthy research subjects, but knowledge of their genetics and immunology has lagged behind that of other high-profile marsupials. Here, we characterise the transcriptome of the long-nose bandicoot (Perameles nasuta), the first high-throughput data set from any peramelomorph. We investigate the immune gene repertoire of the bandicoot, with a focus on key immune gene families, and compare to previously characterised marsupial and mammalian species. We find that the immune gene complement in bandicoot is often conserved with respect to other marsupials; however, the diversity of expressed transcripts in several key families, such as major histocompatibility complex, T cell receptor μ and natural killer cell receptors, appears greater in the bandicoot than other Australian marsupials, including devil and koala. This transcriptome is an important first step for future studies of bandicoots and the bilby, allowing for population level analysis and construction of bandicoot-specific immunological reagents and assays. Such studies will be critical to understanding the immunology and physiology of Peramelemorphia and to inform the conservation of these unique marsupials.