Genome assembly of the numbat (Myrmecobius fasciatus), the only termitivorous marsupial

GigaByte. 2022 Mar 17:2022:gigabyte47. doi: 10.46471/gigabyte.47. eCollection 2022.

Abstract

The numbat (Myrmecobius fasciatus) is an endangered Australian marsupial, and the last surviving member of the Myrmecobiidae family. The numbat regularly undergoes torpor and is unique amongst marsupials as it is the only diurnal and termitivorous species. Here we sequenced the first draft genome of the numbat using 10× Genomics Chromium linked-read technology, resulting in a 3.42 Gbp genome with a scaffold N50 of 223 kbp. A global transcriptome from liver, lung and tongue was also generated to aid genome annotation, identifying 21,465 protein-coding genes. To investigate adaptation to the numbat's termitivorous diet and arid/semi-arid range, we interrogated the most highly expressed transcripts within the tongue and manually annotated taste, vomeronasal and aquaporin gene families. Antimicrobial proteins and proteins involved in digestion were highly expressed in the tongue, alongside umami taste receptors. However, sweet taste receptors were not expressed in this tissue, which combined with the putative contraction of the bitter taste receptor gene repertoire in the numbat genome, may indicate a potential evolutionary adaptation to their specialised termitivorous diet. Vomeronasal and aquaporin gene repertoires were similar to other marsupials. The draft numbat genome is a valuable tool for conservation and can be applied to population genetics/genomics studies and to investigate the unique biology of this interesting species.

Grants and funding

This work has been funded by the Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science (CE200100012) and Discovery Project (DP180102465), and the Bioplatforms Australia Oz Mammals Genomics consortia. LS and PB are each supported by an Australian postgraduate award. TH is supported by a KAKENHI grant from the Japan Society for the Promotion of Science (JSPS) (19K16241, 21H04919, and 21KK0106) and the JSPS Bilateral Joint Research Project “Earth-wide comparative genomics of endangered mammals in Japan and Australia” (JPJSBP 120219902).