Human primordial germ cell commitment in vitro associates with a unique PRDM14 expression profile

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Reproductive Biology

Background:

• Human primordial germ cell (PGC) specification mechanisms are largely unknown due to limited cell access and in vitro models.
• Understanding PGC development is crucial for reproductive medicine and generating gametes.

Purpose of the Study:

• To establish a defined, stepwise in vitro system for inducing human pre-migratory PGC-like cells (PGCLCs) from pluripotent stem cells (PSCs).
• To investigate the molecular mechanisms and developmental pathways of early human germ cell specification.

Main Methods:

• Utilized a stepwise differentiation system involving cytokines to guide PSCs towards PGCLCs.
• Analyzed gene expression patterns, including PRDM14, and DNA methylation status during differentiation.
• Compared human PGCLC development with murine germ cell specification processes.

Main Results:

• Successfully induced PGCLCs from human PSCs through a mesoderm-like intermediate.
• Observed sequential activation of mesodermal and PGC genes, alongside suppression of neural induction and de novo DNA methylation.
• Identified similarities and key differences in early human PGC development compared to mice, particularly in transcriptional regulation (3-6 weeks).

Conclusions:

• Human PGC specification involves epigenesis, driven by inductive signals, similar to mice.
• The developed system provides a valuable model for studying early human germ cell development.
• Further understanding can advance the generation of PSC-derived gametes for reproductive applications.