Eomes restricts Brachyury functions at the onset of mouse gastrulation

• Published in: Developmental cell Vol. 58; no. 18; pp. 1627 - 1642.e7
• Main Authors: Schüle, Katrin M., Weckerle, Jelena, Probst, Simone, Wehmeyer, Alexandra E., Zissel, Lea, Schröder, Chiara M., Tekman, Mehmet, Kim, Gwang-Jin, Schlägl, Inga-Marie, Sagar, Arnold, Sebastian J.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 25.09.2023
• Subjects: Brachyury; chromatin accessibility; endoderm; Eomes; lineage specification; mesoderm; mouse gastrulation; T-box transcription factors; transcriptional control; Brachyury; lineage specification; Eomes; endoderm; transcriptional control; chromatin accessibility; mouse gastrulation; T-box transcription factors; mesoderm
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/j.devcel.2023.07.023

Mammalian specification of mesoderm and definitive endoderm (DE) is instructed by the two related Tbx transcription factors (TFs) Eomesodermin (Eomes) and Brachyury sharing partially redundant functions. Gross differences in mutant embryonic phenotypes suggest specific functions of each TF. To date, the molecular details of separated lineage-specific gene regulation by Eomes and Brachyury remain poorly understood. Here, we combine mouse embryonic and stem-cell-based analyses to delineate the non-overlapping, lineage-specific transcriptional activities. On a genome-wide scale, binding of both TFs overlaps at promoters of target genes but shows specificity for distal enhancer regions that is conferred by differences in Tbx DNA-binding motifs. The unique binding to enhancer sites instructs the specification of anterior mesoderm (AM) and DE by Eomes and caudal mesoderm by Brachyury. Remarkably, EOMES antagonizes BRACHYURY gene regulatory functions in coexpressing cells during early gastrulation to ensure the proper sequence of early AM and DE lineage specification followed by posterior mesoderm derivatives. [Display omitted] •EOMES and BRACHYURY specify distinct mesoderm and endoderm (ME) gene programs in mouse embryos•Distinct programs are mediated by specific TF-binding motifs at non-overlapping enhancers•EOMES restricts BRACHYURY activities to ensure the proper sequence of ME specification Schüle and Weckerle et al. combine chromatin binding and gene expression analysis to identify distinct functions of the two related Tbx factors Eomesodermin and Brachyury in the gastrulating mouse embryo. During gastrulation, Eomesodermin restricts Brachyury functions to ensure spatial and temporal orders of tissue-specific gene programs.