Establishment of DNA methylation during primate germ cell development

Area of Science:

• Epigenetics
• Developmental Biology
• Genomics

Background:

• DNA methylation patterns are reset in primordial germ cells and re-established during mammalian development.
• Understanding de novo methylation in germ cells is crucial for reproductive health and inheritance.

Purpose of the Study:

• To investigate the timing and dynamics of de novo DNA methylation in primate germ cells.
• To compare the DNA methylation establishment process in primate male germ cells with that of mice.

Main Methods:

• Single-cell bisulfite sequencing was employed on spermatogonia from marmosets, macaques, and humans.
• Analysis focused on the genome-wide acquisition of DNA methylation in male germ cell precursors.

Main Results:

• De novo DNA methylation occurs postnatally in male prospermatogonia and female growing oocytes across three primate species.
• Methylation establishment in monkey prospermatogonia spans 6 months to 1 year, with faster acquisition in genic regions.
• Unlike mice, primate prospermatogonia undergo mitotic divisions during methylation establishment, potentially aided by DNMT1 expression.

Conclusions:

• Primate male germ cell de novo methylation is a prolonged postnatal process with distinct features compared to mice.
• The findings highlight species-specific differences in epigenetic reprogramming during germ cell development.