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Harmoush B, Viebahn C, Tsikolia N. Development of node architecture and emergence of molecular organizer characteristics in the pig embryo. Dev Dyn 2024. [PMID: 38733144 DOI: 10.1002/dvdy.715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 03/17/2024] [Accepted: 03/30/2024] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND The avian node is the equivalent of the amphibian Spemann's organizer, as indicated by its ability to induce a secondary axis, cellular contribution, and gene expression, whereas the node of the mouse, which displays limited inductive capacities, was suggested to be a part of spatially distributed signaling. Furthermore, the structural identity of the mouse node is subject of controversy, while little is known about equivalent structures in other mammals. RESULTS We analyzed the node and emerging organizer in the pig using morphology and the expression of selected organizer genes prior to and during gastrulation. The node was defined according to the "four-quarter model" based on comparative consideration. The node of the pig displays a multilayered, dense structure that includes columnar epithelium, bottle-like cells in the dorsal part, and mesenchymal cells ventrally. Expression of goosecoid (gsc), chordin, and brachyury, together with morphology, reveal the consecutive emergence of three distinct domains: the gastrulation precursor domain, the presumptive node, and the mature node. Additionally, gsc displays a ventral expression domain prior to epiblast epithelialization. CONCLUSION Our study defines the morphological and molecular context of the emerging organizer equivalent in the pig and suggests a sequential development of its function.
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Affiliation(s)
- Braah Harmoush
- Institute of Anatomy and Cell Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Christoph Viebahn
- Institute of Anatomy and Cell Biology, University Medical Centre Göttingen, Göttingen, Germany
| | - Nikoloz Tsikolia
- Institute of Anatomy and Cell Biology, University Medical Centre Göttingen, Göttingen, Germany
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Canon E, Jouneau L, Blachère T, Peynot N, Daniel N, Boulanger L, Maulny L, Archilla C, Voisin S, Jouneau A, Godet M, Duranthon V. Progressive methylation of POU5F1 regulatory regions during blastocyst development. Reproduction 2018; 156:145-161. [PMID: 29866767 DOI: 10.1530/rep-17-0689] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 06/01/2018] [Indexed: 01/14/2023]
Abstract
The POU5F1 gene encodes one of the 'core' transcription factors necessary to establish and maintain pluripotency in mammals. Its function depends on its precise level of expression, so its transcription has to be tightly regulated. To date, few conserved functional elements have been identified in its 5' regulatory region: a distal and a proximal enhancer, and a minimal promoter, epigenetic modifications of which interfere with POU5F1 expression and function in in vitro-derived cell lines. Also, its permanent inactivation in differentiated cells depends on de novo methylation of its promoter. However, little is known about the epigenetic regulation of POU5F1 expression in the embryo itself. We used the rabbit blastocyst as a model to analyze the methylation dynamics of the POU5F1 5' upstream region, relative to its regulated expression in different compartments of the blastocyst over a 2-day period of development. We evidenced progressive methylation of the 5' regulatory region and the first exon accompanying differentiation and the gradual repression of POU5F1 Methylation started in the early trophectoderm before complete transcriptional inactivation. Interestingly, the distal enhancer, which is known to be active in naïve pluripotent cells only, retained a very low level of methylation in primed pluripotent epiblasts and remained less methylated in differentiated compartments than the proximal enhancer. This detailed study identified CpGs with the greatest variations in methylation, as well as groups of CpGs showing a highly correlated behavior, during differentiation. Moreover, our findings evidenced few CpGs with very specific behavior during this period of development.
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Affiliation(s)
- E Canon
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - L Jouneau
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - T Blachère
- Univ LyonUniversité Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France
| | - N Peynot
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - N Daniel
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - L Boulanger
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - L Maulny
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - C Archilla
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - S Voisin
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - A Jouneau
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
| | - M Godet
- Univ LyonUniversité Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France
| | - V Duranthon
- UMR BDRINRA, ENVA, Université Paris Saclay, 78350, Jouy en Josas, France
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