Pleomorphic Adenoma Gene 1 Is Needed For Timely Zygotic Genome Activation and Early Embryo Development

Elo Madissoon,Katariina Mamia,Elisabet Einarsdottir,Shintaro Katayama,Pauliina Damdimopoulou,Juha Kere,Kaarel Krjutškov,Anastasios Damdimopoulos,Bert De Groef,Outi Hovatta

doi:10.1038/s41598-019-44882-0

Abstract

Pleomorphic adenoma gene 1 (PLAG1) is a transcription factor involved in cancer and growth. We discovered a de novo DNA motif containing a PLAG1 binding site in the promoters of genes activated during zygotic genome activation (ZGA) in human embryos. This motif was located within an Alu element in a region that was conserved in the murine B1 element. We show that maternally provided Plag1 is needed for timely mouse preimplantation embryo development. Heterozygous mouse embryos lacking maternal Plag1 showed disrupted regulation of 1,089 genes, spent significantly longer time in the 2-cell stage, and started expressing Plag1 ectopically from the paternal allele. The de novo PLAG1 motif was enriched in the promoters of the genes whose activation was delayed in the absence of Plag1. Further, these mouse genes showed a significant overlap with genes upregulated during human ZGA that also contain the motif. By gene ontology, the mouse and human ZGA genes with de novo PLAG1 motifs were involved in ribosome biogenesis and protein synthesis. Collectively, our data suggest that PLAG1 affects embryo development in mice and humans through a conserved DNA motif within Alu/B1 elements located in the promoters of a subset of ZGA genes.

Highlights

Source site for de novo motif discovery Similar site with the de novo motif binding site for the pleomorphic adenoma gene 1 (PLAG1)
The de novo PLAG1 motif was located within a conserved region of an Alu element in close vicinity to an RNA polymerase III promoter A-box, and it partially overlapped with the PRD-like transcription factor motif that we identified in our previous study (Fig. 1c; File S1)[11]
We have discovered a new role for the oncogene PLAG1 in the regulation of zygotic genome activation (ZGA)

Summary

Introduction

Source site for de novo motif discovery Similar site with the de novo motif binding site for the pleomorphic adenoma gene 1 (PLAG1). PLAG1 encodes a C2H2 zinc finger transcription factor and an oncogene that was first characterized in pleomorphic adenomas of the salivary gland[12]. It belongs to the same protein family as the functionally redundant proto-oncogene PLAG-like 2 (PLAGL2) and the imprinted tumor suppressor PLAG-like 1 (PLAGL1). Associations with cancer have been the focus of most studies on PLAG family transcription factors and less is known about their role in normal physiology. There are no reports on PLAG family genes in preimplantation embryo development or pluripotency. By using our human embryo transcriptome data set[11], Plag[1] knockout (KO) mice[14], breeding experiments, single-embryo RNA-seq, and time-lapse analysis of cleavage stage embryo development we show that PLAG1 controls a subset of ZGA genes and is needed for normal cleavage stage embryo development

Methods

Results

Conclusion