Germline/soma distinction in embryos requires regulators of zygotic genome activation. Author Megan Colonnetta, Paul Schedl, Girish Deshpande Publication Year 2023 Type Journal Article Abstract In embryos, somatic versus germline identity is the first cell fate decision. Zygotic genome activation (ZGA) orchestrates regionalized gene expression, imparting specific identity on somatic cells. ZGA begins with a minor wave that commences at nuclear cycle (NC)8 under the guidance of chromatin accessibility factors (Zelda, CLAMP, GAF), followed by the major wave during NC14. By contrast, primordial germ cell (PGC) specification requires maternally deposited and posteriorly anchored germline determinants. This is accomplished by a centrosome coordinated release and sequestration of germ plasm during the precocious cellularization of PGCs in NC10. Here, we report a novel requirement for Zelda and CLAMP during the establishment of the germline/soma distinction. When their activity is compromised, PGC determinants are not properly sequestered, and specification is disrupted. Conversely, the spreading of PGC determinants from the posterior pole adversely influences transcription in the neighboring somatic nuclei. These reciprocal aberrations can be correlated with defects in centrosome duplication/separation that are known to induce inappropriate transmission of the germ plasm. Interestingly, consistent with the ability of bone morphogenetic protein (BMP) signaling to influence specification of embryonic PGCs, reduction in the transcript levels of a BMP family ligand, (), is exacerbated at the posterior pole. Keywords Animals, Drosophila, Drosophila Proteins, Drosophila melanogaster, Gene Expression Regulation, Developmental, Zygote, Germ Cells Journal Elife Volume 12 Date Published 2023 Jan 04 ISSN Number 2050-084X DOI 10.7554/eLife.78188 Alternate Journal Elife PMCID PMC9812407 PMID 36598809 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML