Oral Presentation 16th Asian Conference on Transcription 2019

Epigenetic reprogramming of the brushtail possum (Trichosurus vulpecula) germline (1109)

Melanie K Laird 1 , Tim A Hore 1
  1. University of Otago, Dunedin, OTAGO, New Zealand

Epigenetic reprogramming of mammalian primordial germ cells (PGCs)- the precursors to the sperm and egg cells of adults- occurs in the early embryo as PGCs undergo active genome-wide demethylation following migration to the developing gonad. Demethylation, and subsequent re-methylation, resets parentally-inherited imprints to reflect the sex of the developing embryo.

Our understanding of both the mechanisms and evolution of this phenomenon is in its infancy. Marsupials are fascinating models of germline reprogramming as PGC migration and development occurs largely after birth- in the gonads of developing pouch young. Marsupial PGCs also appear to be reprogrammed post-natally, based on semi-quantitative global studies and single loci analysis of male wallaby PGCs. To further investigate the dynamics of epigenetic memory in marsupials, we isolated germline cells (PGCs) from male and female brushtail possums (Trichosurus vulpecula) throughout gonadal differentiation. We used post-bisulfite adaptor tagging (PBAT) to assess methylation of PGCs in a fully-quantitative manner, assigning reads against the recently-assembled possum genome. Our findings indicate that the mechanisms of germline reprogramming are conserved between marsupials and eutherian mammals, but also divergent. We discuss the potential implications of this work for the generation of transgenic marsupials using a PGC transplantation approach, and in particular, its application for possum biocontrol in New Zealand.