Induction Of Germ-cell Fate From Pluripotent Stem Cells In Vitro

Germ cells are the only cell type that is able to pass genetic information from generation to generation. In vitro derivation of germ cells from the embryonic stem cells (ESCs) has great values for animal breeding, clinical therapy of infertility, and studying the regulatory mechanism of germ cell development. However, most previous studies focused on PGC specification, yet successful generation of terminal differentiated gametes from ESCs remains challenging. Here, we explored the induction of germ cells from mouse ESCs and mouse epiblast stem cells(EpiSCs) by detecting the expression of the key PGC genes, such as Blimp1, CXCR4 and VASA, as well as the markers during spermatogenesis, such as PLZF, GFRal and ACROSIN. We found that expression of these genes are upregulated to various degrees upon induction of mouse germ-cell fate in vitro. In addition, we demonstrated that haploid spermatid-like cells formed from differentiated human ESCs by characterization of expression of marker genes in meiosis, such as ACROSIN and PRM1, as well as by corrected DNA methylation patterns of imprinted loci H19 and PEG10 genes. We further demonstrated that these haploid spermatid-like cells could fertilize mouse oocytes into two-cell embryos when injected.