{ "id": "ep9cf05w28", "slug": "peg-cell", "title": "Peg cell", "updated": "2026-10-20", "topic_path": [ { "id": "life", "label": "Life and health", "api_url": "https://www.edgepedia.org/api/v1/topics/life" }, { "id": "life.biology", "label": "Biological foundations", "api_url": "https://www.edgepedia.org/api/v1/topics/life.biology" }, { "id": "life.biology.development", "label": "Development and comparative physiology", "api_url": "https://www.edgepedia.org/api/v1/topics/life.biology.development" }, { "id": "life.biology.development.developmental-mechanisms-and-comparative-physiology", "label": "Cellular, regenerative, and comparative physiology", "api_url": "https://www.edgepedia.org/api/v1/topics/life.biology.development.developmental-mechanisms-and-comparative-physiology" } ], "geo": [ { "id": "geo.weu.t1800.life.biology.development", "label": "Western Europe · 1800 to 1945: Development and comparative physiology", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.weu.t1800.life.biology.development", "path": [ { "id": "geo.weu", "label": "Western Europe", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.weu" }, { "id": "geo.weu.t1800", "label": "Western Europe · 1800 to 1945", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.weu.t1800" }, { "id": "geo.weu.t1800.life", "label": "Life and health", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.weu.t1800.life" }, { "id": "geo.weu.t1800.life.biology", "label": "Biological foundations", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.weu.t1800.life.biology" }, { "id": "geo.weu.t1800.life.biology.development", "label": "Development and comparative physiology", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.weu.t1800.life.biology.development" } ] } ], "excerpt": "Peg cell: non-ciliated secretory cell of the oviduct (fallopian tube) epithelium, also called intercalary or Stiftchenzellen; secretes nutrients for the ovum, prominent at ovulation, and shows stem-like regenerative properties.", "snippet": "Peg cell: non-ciliated secretory cell of the oviduct (fallopian tube) epithelium, also called intercalary or Stiftchenzellen; secretes nutrients for the ovum, prominent at ovulation, and shows stem-like regenerative properties.", "node": "life.biology.development.developmental-mechanisms-and-comparative-physiology", "markdown": "# Peg cell\n\nA **peg cell** is a non-ciliated [secretory cell](https://www.edgepedia.org/secretory-cell) of the oviduct (fallopian tube) epithelium, wedged between the more numerous ciliated cells. The name traces to the German *Stiftchenzellen*, a rare third cell type identified over a century ago that appeared like slender pegs driven between the other cells; it has also been called an intercalary cell because the small cells were often found intercalated between adjacent ciliated and secretory cells.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC4442093/)\n\n| Key fact | Detail |\n|---|---|\n| Definition | Non-ciliated secretory cell of the oviduct epithelium, wedged between ciliated cells[2](https://sites.tufts.edu/histologyimages/female-reproductive-system/670/epithelium-of-ovdicut-mucosa/) |\n| Function | Secretes nutrient material for the ovum; secretion lubricates the tube and provides nourishment and protection to the traveling ovum[3](https://histology.leeds.ac.uk/home/female/oviduct/) • [4](https://www.medcell.org/histology/female_reproductive_system_lab/oviduct_epithelium.php) |\n| Secretion | Nonciliated cells that secrete a glycoprotein film covering the epithelium[5](https://www.uomus.edu.iq/img/lectures21/MUCLecture_2025_51935988.pdf) |\n| Timing | Particularly prominent at day 14 of the menstrual cycle, around the time of ovulation[3](https://histology.leeds.ac.uk/home/female/oviduct/) |\n| Markers | Marked with EPCAM, CD44, and ITGA6; peg cell markers include LGR5, NOTCH2, COL1A2, and SERINC5[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC4442093/) • [6](https://pmc.ncbi.nlm.nih.gov/articles/PMC11954873/) |\n| Regenerative role | Peg cells can expand and form organoids containing both ciliated and secretory cells, indicating potential stem cell or progenitor properties[7](https://www.mdpi.com/2073-4409/15/3/269) |\n\n## Structure and identification\n\nThe oviduct is lined by a simple columnar epithelium containing ciliated cells and non-ciliated secretory cells, with peg cells wedged between the ciliated cells.[2](https://sites.tufts.edu/histologyimages/female-reproductive-system/670/epithelium-of-ovdicut-mucosa/) Histologically, peg cells have darker nuclei that lie closer to the lumen than those of the ciliated cells.[2](https://sites.tufts.edu/histologyimages/female-reproductive-system/670/epithelium-of-ovdicut-mucosa/) They have an extensive [Golgi apparatus](https://www.edgepedia.org/golgi-apparatus) above the nucleus, toward the apical surface, consistent with their secretory function.[3](https://histology.leeds.ac.uk/home/female/oviduct/)\n\nSome authorities classify the peg cell as a third epithelial cell type alongside ciliated and secretory cells, describing it as either an undifferentiated state or an altered, functionally depleted form of ciliated or secretory cells.[8](https://www.sciencedirect.com/topics/medicine-and-dentistry/oviduct) In the rat, an electron microscopic analysis reported that peg cells appear to be the morphological image of necrobiotic cells, either ciliated or secretory.[9](https://pubmed.ncbi.nlm.nih.gov/6114052/) Other work characterizes peg cells as a distinct cell type: in human fallopian tube, a basally located population marked with [EPCAM](https://www.edgepedia.org/epcam), CD44, and ITGA6 lacks both the ciliated marker TUBB4 and the secretory marker PAX8, and this cell was identified as the peg cell.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC4442093/)\n\n## Function\n\nPeg cells secrete fluid that provides nutrients for the ovum or fertilized zygote, and their secretion lubricates the tube and provides nourishment and protection to the traveling ovum.[4](https://www.medcell.org/histology/female_reproductive_system_lab/oviduct_epithelium.php) • [10](https://www.histologyguide.org/slideview/MHS-220-oviduct/18-slide-1.html) Together with ciliated cells, which move the ovum toward the uterus, they make the microenvironment of the oviduct suitable for gamete transport, fertilization, and zygote transport.[2](https://sites.tufts.edu/histologyimages/female-reproductive-system/670/epithelium-of-ovdicut-mucosa/) Their secretion has also been described as a glycoprotein film covering the epithelium.[5](https://www.uomus.edu.iq/img/lectures21/MUCLecture_2025_51935988.pdf)\n\nThe cells vary with the reproductive cycle. They are particularly prominent at day 14 of the menstrual cycle, around the time of ovulation.[3](https://histology.leeds.ac.uk/home/female/oviduct/) In a study of human oviducts, mature ciliated and secretory cells were observed only at mid-cycle, while atrophy, deciliation, and loss of secretory activity coincided with elevated serum progesterone.[11](https://onlinelibrary.wiley.com/doi/abs/10.1002/aja.1001560405)\n\n## Stem-like properties and disease relevance\n\nWhen separated from other tissue using a characteristic set of surface antigens, peg cells act as the fallopian tube's regenerative cells in vitro; such stem-like cells cluster at the tube's fimbriated far end and occur in greater numbers in tubal samples taken from patients with serous carcinoma.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC4442093/) [In vitro](https://www.edgepedia.org/in-vitro) studies have shown that peg cells can expand and form organoids containing both ciliated and secretory cells, indicating potential stem cell or progenitor properties.[7](https://www.mdpi.com/2073-4409/15/3/269)\n\nRegional variation has been reported at the transcript level: markers of OVGP1-producing secretory cells identified as peg cells, including [LGR5](https://www.edgepedia.org/lgr5), NOTCH2, COL1A2, and SERINC5, were enriched approaching the ampulla, with highest expression in the ampulla and infundibulum and lower expression in the fimbria (fringed, finger-like open end of the fallopian tube) and isthmus in one dataset, though these trends were not replicated in a validation dataset.[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC11954873/)\n\n## References\n\n1. [Paik et al. (2012). Stem-like epithelial cells are concentrated in the distal end of the fallopian tube: a site for injury and serous cancer initiation. STEM CELLS / PMC.](https://pmc.ncbi.nlm.nih.gov/articles/PMC4442093/)\n2. [Epithelium of oviduct mucosa, Collection of Histology Images, Tufts University](https://sites.tufts.edu/histologyimages/female-reproductive-system/670/epithelium-of-ovdicut-mucosa/)\n3. [Oviduct, The Histology Guide, University of Leeds](https://histology.leeds.ac.uk/home/female/oviduct/)\n4. [Oviduct Epithelium, MedCell Histology](https://www.medcell.org/histology/female_reproductive_system_lab/oviduct_epithelium.php)\n5. [Oviduct microscopic structure lecture, University of Al-Muthanna](https://www.uomus.edu.iq/img/lectures21/MUCLecture_2025_51935988.pdf)\n6. [Spatial transcriptomic profiling of the human fallopian tube epithelium reveals region-specific gene expression patterns, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC11954873/)\n7. [Functional Changes in the Fallopian Tube: Environmental Factors, Lifestyle, Pathological Conditions and Pharmacological Agents, Cells (MDPI)](https://www.mdpi.com/2073-4409/15/3/269)\n8. [Oviduct, an overview, ScienceDirect Topics](https://www.sciencedirect.com/topics/medicine-and-dentistry/oviduct)\n9. [Ultrastructure of the oviductal mucosa of the rat. III. Basal and peg cells. Int J Fertil 1980, PubMed](https://pubmed.ncbi.nlm.nih.gov/6114052/)\n10. [Oviduct, Histology Guide slide MHS 220](https://www.histologyguide.org/slideview/MHS-220-oviduct/18-slide-1.html)\n11. [Verhage 1979, Cyclic changes in ciliation, secretion and cell height of the oviductal epithelium in women, American Journal of Anatomy](https://onlinelibrary.wiley.com/doi/abs/10.1002/aja.1001560405)\n\n---\n*Topic: Encyclopedia › Life and health › Biological foundations › Development and comparative physiology › Cellular, regenerative, and comparative physiology*\n\n*Initially written Oct 20, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/peg-cell", "markdown_url": "https://www.edgepedia.org/peg-cell.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"Peg cell\", Edgepedia (EdgeChat), https://www.edgepedia.org/peg-cell. Edgepedia Community License 1.0.", "credit_md": "\"[Peg cell](https://www.edgepedia.org/peg-cell)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/peg-cell](https://www.edgepedia.org/peg-cell). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"Peg cell\", Edgepedia (EdgeChat), https://www.edgepedia.org/peg-cell. Edgepedia Community License 1.0.", "speakable": "Peg cell: non-ciliated secretory cell of the oviduct epithelium, also called intercalary or Stiftchenzellen; secretes nutrients for the ovum, prominent at ovulation, and shows stem-like regenerative properties." }