A critical role of PRDM14 in human primordial germ cell fate revealed by inducible degrons

Anastasiya Sybirna,Merrick Pierson Smela,Ran Brosh,Sabine Dietmann,Walfred W C Tang,M Azim Surani,Wolfram H Gruhn

doi:10.1038/s41467-020-15042-0

Abstract

PRDM14 is a crucial regulator of mouse primordial germ cells (mPGCs), epigenetic reprogramming and pluripotency, but its role in the evolutionarily divergent regulatory network of human PGCs (hPGCs) remains unclear. Besides, a previous knockdown study indicated that PRDM14 might be dispensable for human germ cell fate. Here, we decided to use inducible degrons for a more rapid and comprehensive PRDM14 depletion. We show that PRDM14 loss results in significantly reduced specification efficiency and an aberrant transcriptome of hPGC-like cells (hPGCLCs) obtained in vitro from human embryonic stem cells (hESCs). Chromatin immunoprecipitation and transcriptomic analyses suggest that PRDM14 cooperates with TFAP2C and BLIMP1 to upregulate germ cell and pluripotency genes, while repressing WNT signalling and somatic markers. Notably, PRDM14 targets are not conserved between mouse and human, emphasising the divergent molecular mechanisms of PGC specification. The effectiveness of degrons for acute protein depletion is widely applicable in various developmental contexts.

Highlights

PRDM14 is a crucial regulator of mouse primordial germ cells, epigenetic reprogramming and pluripotency, but its role in the evolutionarily divergent regulatory network of human PGCs remains unclear
We reveal an indispensable role for PRDM14 in germ cell fate, since loss of function affects the efficiency of specification and results in an aberrant hPGC-like cells (hPGCLCs) transcriptome
Using two acute protein depletion strategies, combined with rescue, transcriptomic and chromatin immunoprecipitation (ChIP)-seq experiments, we demonstrate that PRDM14 is required for hPGCLC specification and represses somatic differentiation while promoting germline fate (Supplementary Fig. 9)

Summary

Introduction

PRDM14 is a crucial regulator of mouse primordial germ cells (mPGCs), epigenetic reprogramming and pluripotency, but its role in the evolutionarily divergent regulatory network of human PGCs (hPGCs) remains unclear. Chromatin immunoprecipitation and transcriptomic analyses suggest that PRDM14 cooperates with TFAP2C and BLIMP1 to upregulate germ cell and pluripotency genes, while repressing WNT signalling and somatic markers. Understanding whether PRDM14 has a role in hPGC specification is critical towards gaining insights on the molecular divergence between mouse and human PGCs. An inducible system for PRDM14 loss of function during hPGCLC specification from hESCs is critical, since PRDM14 is vital for hESC pluripotency[13]. We reveal an indispensable role for PRDM14 in germ cell fate, since loss of function affects the efficiency of specification and results in an aberrant hPGCLC transcriptome. The study illustrates the power of conditional degrons, which can be widely used to study TFs during cell fate determination

Methods

Results

Conclusion