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Popovic M, Bialecka M, Gomes Fernandes M, Taelman J, Van Der Jeught M, De Sutter P, Heindryckx B, Chuva De Sousa Lopes SM. Human blastocyst outgrowths recapitulate primordial germ cell specification events. Mol Hum Reprod 2020; 25:519-526. [PMID: 31211841 PMCID: PMC6802404 DOI: 10.1093/molehr/gaz035] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 04/29/2019] [Indexed: 01/08/2023] Open
Abstract
Our current knowledge of the mechanisms leading to human primordial germ cell (PGC) specification stems solely from differentiation experiments starting from human pluripotent stem cells. However, information regarding the origin of PGCs in vivo remains obscure. Here we apply an improved system for extended in vitro culture of human embryos to investigate the presence of PGC-like cells (PGCLCs) 12 days post fertilization (dpf). Good quality blastocysts (n = 141) were plated at 6 dpf and maintained in hypoxia, in medium supplemented with Activin A until 12 dpf. We primarily reveal that 12 dpf outgrowths recapitulate human peri-implantation events and demonstrate that blastocyst quality significantly impacts both embryo viability at 12 dpf, as well as the presence of POU5F1+ cells within viable outgrowths. Moreover, detailed examination of 12 dpf blastocyst outgrowths revealed a population of POU5F1+, SOX2– and SOX17+ cells that may correspond to PGCLCs, alongside POU5F1+ epiblast-like cells and GATA6+ endoderm-like cells. Our findings suggest that, in human, PGC precursors may become specified within the epiblast and migrate either transiently to the extra-embryonic mesoderm or directly to the dorsal part of the yolk sac endoderm around 12 dpf. This is a descriptive analysis and as such the conclusion that POU5F1+ and SOX17+ cells represent bona fide PGCs can only be considered as preliminary. In the future, other PGC markers may be used to further validate the observed cell populations. Overall, our findings provide insights into the origin of the human germline and may serve as a foundation to further unravel the molecular mechanisms governing PGC specification in human.
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Affiliation(s)
- Mina Popovic
- Ghent Fertility And Stem cell Team (G-FAST), Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Monika Bialecka
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg, Leiden, The Netherlands
| | - Maria Gomes Fernandes
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg, Leiden, The Netherlands
| | - Jasin Taelman
- Ghent Fertility And Stem cell Team (G-FAST), Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.,Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg, Leiden, The Netherlands
| | - Margot Van Der Jeught
- Ghent Fertility And Stem cell Team (G-FAST), Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Petra De Sutter
- Ghent Fertility And Stem cell Team (G-FAST), Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Björn Heindryckx
- Ghent Fertility And Stem cell Team (G-FAST), Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Susana M Chuva De Sousa Lopes
- Ghent Fertility And Stem cell Team (G-FAST), Department of Reproductive Medicine, Ghent University Hospital, Ghent, Belgium.,Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg, Leiden, The Netherlands
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