STAT3 Is an Upstream Regulator of Granzyme G in the Maternal-To-Zygotic Transition of Mouse Embryos

The maternal-to-zygotic transition (MZT), which controls maternal signaling to synthesize zygotic gene products, promotes the preimplantation development of mouse zygotes two-cell stage. Our previous study reported that granzyme g (Gzmg), a serine-type protease, is required for MZT. In this study, we further identified factors regulate Gzmg promoter activity in zygote stage embryos. A full-length from genomic DNA, FL-pGzmg (−1696~+28 nt), was cloned, and four deletion constructs promoter, Δ1-pGzmg (−1369~+28 Δ2-pGzmg (−939~+28 Δ3-pGzmg (−711~+28 nt) Δ4-pGzmg (−417~+28 were subsequently generated. Different-sized promoters used perform assays results showed promoted highest expression level enhanced green fluorescent protein (EGFP) reporter data suggested time-specific transcription upregulated by binding cis-elements −417~+28-nt region. According assay, factor sites predicted analyzed with JASPAR database, two factors, signal transducer activator 3 (STAT3) GA-binding alpha (GABPα), identified. Furthermore, STAT3 GABPα are expressed located pronuclei nuclei confirmed immunofluorescence staining; however, only recruited injected construct. These indicated may upregulate promote treatment inhibitor, S3I-201, caused embryonic arrest at stages. suggest STAT3, protein, critical regulates It plays an important role during early development.