Oral Virtual Presentation (Virtual only) ESA-SRB-ANZBMS 2021

Deriving induced pluripotent stem cells (iPSCs) for the Fat-tailed dunnart (#237)

Ashlee Hutchinson 1 , Irene Gallego Romero 1 , Neke Ibeh 1 , Stephen Frankenberg 1 , Andrew Pask 1
  1. University of Melbourne, Victoria, Australia

Marsupial models have so much to teach us about fundamental mammalian biology. However, essential technologies that are well defined for conventional laboratory models are concerningly underdeveloped for our marsupials. Stem cells are an integral tool for studying developmental biology and genetics. Unfortunately, the absence of an inner cell mass in marsupial embryos prevents the isolation of embryonic stem cells. Instead, we focused on the generation of induced pluripotent stem cells (iPSCs) as an equivalent alternative, using the Fat tailed dunnart as a model. iPSCs are produced by transfecting somatic cells with pluripotency genes in a process known as reprogramming. The induction of reprogramming is controlled by a highly conserved set of core factors. However, the conditions required for its completion are usually species specific, requiring additional genes, small molecules, specialised culture conditions or other variations in the derivation protocol. I have tested combinations of reprogramming plasmids, media and several small molecule supplements to refine conditions for reproducibly producing iPSCs from dunnart fibroblasts. This protocol has now been used to produce two distinct lines and multiple clones. Cells show high expression of pluripotency markers as validated using qPCR and immunocytochemistry. In concordance with other marsupial work, higher expression of POU5F3 relative to OCT3/4 has been observed. Embryoid bodies have been produced for both lines in both suspension and adhesion conditions. These have been shown to differentiate into non-stem lineages. Single cell gene expression libraries have been produced and sequenced, making these cells an important resource for marsupial pluripotency. iPSC technology makes the dunnart a tractable model for identifying conserved regulatory pathways in mammalian development. The use of stem cells should also have vast implications for marsupial conservation efforts.