Molecular-Genetic Mechanisms of Somatic Cell Reprogramming for Reproductive Biology Applications
Keywords:
in vitro gametogenesis, induced pluripotent stem cells, primordial germ cellsAbstract
The article examines a spectrum of molecular-genetic mechanisms that enable the reprogramming of differentiated somatic cells into gametes within the context of rapidly advancing in vitro gametogenesis (IVG) and its prospective applications in reproductivemedicine and biodiversity conservation. The objective is to provide a comprehensive analysis of human-specific signaling pathways, transcriptional networks, and epigenetic modifications that determine the competence of pluripotent cells to enter the germline program, and to evaluate the performance of contemporary IVG protocols. The relevance of this topic stems from the fact that, despite successful implementation of the complete IVG cycle in mice, translation of analogous approaches to humans encounters fundamental divergences in the architecture of gene regulatory networks and unresolved epigenetic safety issues, particularly with respect to genomic imprinting and meiotic errors. The scientific novelty of this review lies in the integration of data from 2010–2025 with an emphasis on the human SOX17–BLIMP1–TFAP2C network, the temporal and dose-dependent interpretation of BMP/WNT signals, two-wave epigenetic reprogramming, and the critical role of metabolic tuning (N2B27, NAC, hypoxia) in sustaining germline competence. It is demonstrated that the principal limitation of IVG is not the mere derivation of pluripotent cells, but rather their positioning along a continuum of states (primed/naïve, iMeLC), the completeness of erasure of epigenetic memory, and thefidelity of meiotic progression; moreover, current 3D models of the gonadal niche (xrOvary, rOv) and synthetic gametogenesis strategies only partially mitigate these barriers and do not eliminate the risks of epigenetic insufficiency in the resulting gametes. The article is intended for researchers in human reproductive biology, regenerative medicine, stem cell biology, and reproductive tissue bioengineering.
References
Y. Luo and Y. Yu, “Research Advances in Gametogenesis and Embryogenesis Using Pluripotent Stem Cells,” Frontiers in Cell and Developmental Biology, vol. 20, no. 9, p. 801468, Jan. 2022, doi:https://doi.org/10.3389/fcell.2021.801468.2.K. Hayashi, C. Galli, S. Diecke, and T. B. Hildebrandt, “Artificially produced gametes in mice, humans and other species,” Reproduction Fertility and Development, vol. 33, pp. 91–101, Jan. 2021, doi:https://doi.org/10.1071/rd20265.3.M. V. Romualdez-Tan, “Modelling in vitro gametogenesis using induced pluripotent stem cells: A review,” Cell Regeneration, vol. 12, no. 33, Oct. 2023, doi:https://doi.org/10.1186/s13619-023-00176-5.4.P. Karagiannis et al., “Induced Pluripotent Stem Cells and Their Use in Human Models of Disease and Development,” Physiological Reviews, vol. 99, no. 1, pp. 79–114, Jan. 2019, doi:https://doi.org/10.1152/physrev.00039.2017.5.S. Dhaiban, S. Chandran, M. Noshi, and A. A. Sajini, “Clinical translation of human iPSC technologies: advances, safety concerns, and future directions,” Frontiers in Cell and Developmental Biology, vol. 13, Sep. 2025, doi:https://doi.org/10.3389/fcell.2025.1627149.6.O. Hikabe et al., “Reconstitution in vitro of the entire cycle of the mouse female germ line,” Nature, vol. 539, no. 7628, pp. 299–303, Oct. 2016, doi:https://doi.org/10.1038/nature20104.7.H. Yu et al., “The establishment and regulation of human germ cell lineage,” Stem Cell Research & Therapy, vol. 16, p. 139, Mar. 2025, doi:https://doi.org/10.1186/s13287-025-04171-2.8.A. W. Overeem et al., “Efficient and scalable generation of primordial germ cells in 2D culture using basement membrane extract overlay,” Cell Reports Methods, vol. 3, no. 6, p. 100488, Jun. 2023, doi:https://doi.org/10.1016/j.crmeth.2023.100488.9.N. Irie et al., “SOX17 Is a Critical Specifier of Human Primordial Germ Cell Fate,” Cell, vol. 160, pp. 253–268, Jan. 2015, doi:https://doi.org/10.1016/j.cell.2014.12.013.10.S.-M. Lee and M. A. Surani, “Epigenetic reprogramming in mouse and human primordial germ cells,” Experimental & Molecular Medicine, vol. 56, pp. 2578–2587, Dec. 2024, doi:https://doi.org/10.1038/s12276-024-01359-z.11.I. M. Saadeldin, S. Ehab, M. Essa, A. M. Abdelazim, and A. M. Assiri, “The Mammalian Oocyte: A Central Hub for Cellular Reprogramming and Stemness,” Stem Cells and Cloning Advances and Applications, vol. 18, pp. 15–34, Feb. 2025, doi:https://doi.org/10.2147/sccaa.s513982.12.J. P. Burgstaller and M. R. Chiaratti, “Mitochondrial Inheritance Following Nuclear Transfer: From Cloned Animals to Patientswith Mitochondrial Disease,” Methods in molecular biology, vol. 2647, pp. 83–104, 2023, doi:https://doi.org/10.1007/978-1-0716-3064-8_4.13.Y. Chen, M. Li, and Y. Wu, “The occurrence and development of induced pluripotent stem cells,” Frontiers in genetics, vol. 15, Apr. 2024, doi:https://doi.org/10.3389/fgene.2024.1389558.14.Y.-H. Lin, J. D. Lehle, and J. R. McCarrey, “Source cell-type epigenetic memory persists in induced pluripotent cells but is lost in subsequently derived germline cells,” Frontiers in cell and developmental biology, vol. 12, p. 1306530, Feb. 2024, doi:https://doi.org/10.3389/fcell.2024.1306530.15.M.-T. Zhao et al., “Molecular and functional resemblance of differentiated cells derived from isogenic human iPSCs and SCNT-derived ESCs,” Proceedings of the National Academy of Sciences, vol. 114, no. 52, pp. E11111–E11120, Dec. 2017, doi:https://doi.org/10.1073/pnas.1708991114.16.A. Reda, J.-B. Stukenborg, and Q. Deng, “Differentiation of Human-Induced Pluripotent Stem Cells (hiPSCs) into Human Primordial Germ Cell-like Cells (hPGCLCs) In Vitro,” Methods in molecular biology, vol. 2490, pp. 235–249, 2022, doi:
American Academic Publisherpg. 817https://www.academicpublishers.org/journals/index.php/ijms/indexhttps://doi.org/10.1007/978-1-0716-2281-0_17.17.M. V. Santos et al., “Generating human primordial germ cell-like cells from pluripotentstem cells: a scoping review of in vitro methods,” Human Reproduction Open, vol. 2025, no. 4, p. hoaf056, Jan. 2025, doi:https://doi.org/10.1093/hropen/hoaf056.18.E. Camacho-Aguilar, S. T. Yoon, M. A. Ortiz-Salazar, S. Du, M. C. Guerra, and A. Warmflash, “Combinatorial interpretation of BMP and WNT controls the decision between primitive streak and extraembryonic fates,” Cell Systems, vol. 15, no. 5, pp. 445-461.e4, May 2024, doi:https://doi.org/10.1016/j.cels.2024.04.001.19.Q. Luo et al., “Epiblast-like stem cells established by Wnt/β-catenin signaling manifest distinct features of formative pluripotency and germline competence,” Cell Reports, vol. 42, no. 1, p. 112021, 2023, doi:https://doi.org/10.1016/j.celrep.2023.112021.20.M. Tian and M. Zhang, “Advances in in vitro oocyte generation from pluripotent stem cells and ovarian stem cells,” Frontiers in Endocrinology, vol. 16, p.1515253, Aug. 2025, doi:https://doi.org/10.3389/fendo.2025.1515253.21.W. W. C. Tang et al., “Sequential enhancer state remodelling defines human germline competence and specification,” Nature Cell Biology, vol. 24, no. 4, pp. 448–460, Apr. 2022, doi:https://doi.org/10.1038/s41556-022-00878-z.22.L. A. Fischer et al., “Tracking and mitigating imprint erasure during induction of naive human pluripotency at single-cell resolution,” Stem Cell Reports, vol. 20, no. 3, p. 102419, Mar. 2025, doi:https://doi.org/10.1016/j.stemcr.2025.102419.23.F. Passaretti et al., “Different Mechanisms Cause Hypomethylation of Both H19 and KCNQ1OT1 Imprinted Differentially Methylated Regions in Two Cases of Silver–Russell Syndrome Spectrum,” Genes, vol. 13, no. 10, p. 1875, Oct. 2022, doi:https://doi.org/10.3390/genes13101875.24.S. M. Czukiewska, C. M. Roelse, and S. M. Chuva de Sousa Lopes, “Human and non-human primate female in vitro gametogenesis toward meiotic entry: a systematic review,” Fertility and Sterility, vol. 124, no. 1, pp. 6–21, May 2025, doi:https://doi.org/10.1016/j.fertnstert.2025.04.040.25.G. Yuan et al., “Improving in vitro induction efficiency of human primordial germ cell-like cells using N2B27 or NAC-based medium,” Journal of Biomedical Research, vol. 39, no. 6, p. 587, Jan. 2025, doi:https://doi.org/10.7555/jbr.38.20240433.26.S. Vijayakumar et al., “Monolayer platform to generate and purify primordial germ-like cells in vitro provides insights into human germline specification,” Nature Communications, vol. 14, p. 5690, Sep. 2023, doi:https://doi.org/10.1038/s41467-023-41302-w.27.M. Kobayashi et al., “Expanding homogeneous culture of human primordial germ cell-like cells maintaining germline features without serum or feeder layers,” Stem Cell Reports, vol. 17, no. 3, pp. 507–521, Mar. 2022, doi:https://doi.org/10.1016/j.stemcr.2022.01.012.28.C. Yamashiro et al., “Generation of human oogonia from induced pluripotent stem cells in vitro,” Science, vol.362, no. 6412, pp. 356–360, Sep. 2018, doi:https://doi.org/10.1126/science.aat1674.29.Y. Kuse et al., “Placenta-derived factors contribute to human iPSC-liver organoid growth,” Nature Communications, vol. 16, p. 2493, Spring 2025, doi:https://doi.org/10.1038/s41467-025-57551-w.30.C. Charalambous, A. Webster, and M. Schuh, “Aneuploidy in mammalian oocytes and the impact of maternal ageing,” Nature Reviews Molecular Cell Biology, vol. 24, pp. 27–44, Sep. 2022, doi:https://doi.org/10.1038/s41580-022-00517-3.31.E. Choong, E. P. Dawson, K. Bowman, and E. Y. Adashi, “In vitro gametogenesis (IVG): reflections from a workshop,” Journal of Assisted Reproduction and Genetics, vol. 41, pp. 3323–3326, Summer 2024, doi:https://doi.org/10.1007/s10815-024-03266-8.32.M. P. Smela et al., “Rapid human oogonia-like cell specification via transcription factor-directed differentiation,” EMBO Reports, vol. 26, no. 4, pp. 1114–1143, Jan. 2025, doi:https://doi.org/10.1038/s44319-025-00371-2.
