Long-term expansion with germline potential of human primordial germ cell-like cells in vitro

EMBO J. 2020 Nov 2;39(21):e104929. doi: 10.15252/embj.2020104929. Epub 2020 Sep 20.


Human germ cells perpetuate human genetic and epigenetic information. However, the underlying mechanism remains elusive, due to a lack of appropriate experimental systems. Here, we show that human primordial germ cell-like cells (hPGCLCs) derived from human-induced pluripotent stem cells (hiPSCs) can be propagated to at least ~106 -fold over a period of 4 months under a defined condition in vitro. During expansion, hPGCLCs maintain an early hPGC-like transcriptome and preserve their genome-wide DNA methylation profiles, most likely due to retention of maintenance DNA methyltransferase activity. These characteristics contrast starkly with those of mouse PGCLCs, which, under an analogous condition, show a limited propagation (up to ~50-fold) and persist only around 1 week, yet undergo cell-autonomous genome-wide DNA demethylation. Importantly, upon aggregation culture with mouse embryonic ovarian somatic cells in xenogeneic-reconstituted ovaries, expanded hPGCLCs initiate genome-wide DNA demethylation and differentiate into oogonia/gonocyte-like cells, demonstrating their germline potential. By creating a paradigm for hPGCLC expansion, our study uncovers critical divergences in expansion potential and the mechanism for epigenetic reprogramming between the human and mouse germ cell lineage.

Keywords: epigenetic reprogramming; hPGC-like cells; human primordial germ cells; in vitro expansion; oogonia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • DNA Demethylation
  • DNA Methylation
  • Embryonic Stem Cells / metabolism
  • Epigenesis, Genetic
  • Epigenomics
  • Female
  • Genome
  • Germ Cells / metabolism*
  • Humans
  • Induced Pluripotent Stem Cells / cytology
  • Induced Pluripotent Stem Cells / metabolism
  • Mice
  • Ovary / embryology*
  • Pluripotent Stem Cells / cytology*
  • Pluripotent Stem Cells / metabolism*