In vitro germ cell differentiation from cynomolgus monkey embryonic stem cells

Area of Science:

• Stem cell biology
• Reproductive biology
• Primate research

Background:

• Embryonic stem (ES) cells from mice and primates can differentiate into germ cells in vitro.
• Limited knowledge exists on primate ES cell differentiation markers and culture conditions.
• Monkey ES cells offer a valuable model for studying primate gametogenesis.

Purpose of the Study:

• To investigate the potential of cynomolgus monkey ES cells to differentiate into germ cells in vitro.
• To identify reliable markers for detecting primate germ cells derived from ES cells.

Main Methods:

• Examined germ cell marker gene expression (VASA, NANOS, PIWIL1) in cynomolgus monkey ES cells during embryoid body (EB) formation.
• Utilized immunocytochemistry to identify cells expressing stage-specific embryonic antigen (SSEA) 1, OCT-4, and VASA proteins.
• Assessed the impact of conditioned medium and growth factors (BMP4) on germ cell differentiation, including meiotic marker SCP1 expression.

Main Results:

• VASA expression increased significantly during EB differentiation, indicating germ cell development.
• NANOS and PIWIL1 gene expression were upregulated as EB differentiation progressed.
• Specific cell populations expressing SSEA1, OCT-4, and VASA were identified in EBs.
• BMP4 addition enhanced the expression of the meiotic marker SCP1.

Conclusions:

• VASA is a crucial marker for identifying primate germ cells differentiated from ES cells in vitro.
• Established germ cell markers (SSEA1, OCT-4, VASA) are effective for characterizing in vitro derived germ cells.
• These findings contribute to understanding primate germ cell development.