Maternal Plag1 deficiency delays two-cell stage embryo development and embryonic genome activation [Embryos]

Pleomorphic adenoma gene 1 (PLAG1) encodes a transcription factor involved in cancer and growth. We study the role of PLAG1 in preimplantation embryos using STRT RNA-seq of single embryos from wild type and knockout mothers (both mated with wild type studs). The lack of maternal Plag1 led to delayed mouse 2-cell stage embryo development, compensatory expression of Plag1 from the paternal allele, and dysregulation of 1,089 genes. Half of these genes displayed a pattern of delayed activation and play roles in ribosome biogenesis and protein synthesis. These mouse genes further showed a significant overlap with human EGA genes with similar ontology, and an enrichment of the PLAG1 de novo motif. We conclude that Plag1 affects EGA through retrotransposons influencing ribosomes and protein synthesis, a mechanism that might also explain its roles in cancer and growth Overall design: Single wild type and maternal Plag1 knockout embryos at MII, 2-cell and 8-cell stage development in 14-16 biologicla replicas per developmental stage and genotype.