University Duisburg-Essen Institute of Anatomy, Essen


Prof. Dr. med. Dr. rer. nat.
Hans-Werner Denker
phone: +49 (0)201 403792
fax: +49 (0)201 4377593
Deutsche Version English Version

Hans-Werner Denker – University Duisburg-Essen

Prof. H.-W. Denker Hans-Werner Denker, Prof. Dr. med. Dr. rer. nat.
Chair of Anatomy and Developmental Biology
Institute of Anatomy, Medical Faculty, University Duisburg-Essen (Germany)
Retired since March 2006

Research Topics

Cell and developmental biology:
Embryo implantation; cell biology of uterine epithelium and its receptive state; trophoblast; in vitro investigations of trophoblastic and choriocarcinoma cell lines; cell-cell interactions, cell-matrix interactions, cell differentiation, mechanisms of invasion.
Developmental biology of early mammalian embryos.

Pluripotent stem cells:
Differentiation potential (totipotency, omnipotency, pluripotency) and ethical implications.

Recent own Publications (view all)

  • DENKER, H.-W.:
    Rise of the rabbit model for implantation research. A commemoration of the scientific work of Bent G. Boving (1920-2019).
    Biology of Reproduction 102 (6): 1170-1176 (2020); doi:
    PubMed   BOR   BOR (free access)
  • DENKER, H.-W.:
    Recent embryo twinning data prompt reconsideration of theories on a crucial role of segregation of oocyte cytoplasmic constituents in mammals.
    (Comment on: CASSER, E., WDOWIK, S., ISRAEL, S., WITTEN, A., SCHLATT, S., NORDHOFF, V., BOIANI, M.: Differences in blastomere totipotency in 2-cell mouse embryos are a maternal trait mediated by asymmetric mRNA distribution. Molec. Hum. Reproduct. 25/11, 729-744, 2019; doi:
    Molec. Hum. Reprod. 26: 193-198 (2020); doi:
    PubMed   MHR   PDF-Download AOV (214 KB)
  • DENKER, H.-W.:
    Embryonen, Embryoide, Gastruloide... Ethische Aspekte zur Selbstorganisation und zum Engineering von Stammzellkolonien und Embryonen.
    In: M. Rothhaar, M. Hähnel, R. Kipke (Eds.): Der manipulierbare Embryo. Potentialitäts- und Speziesargumente auf dem Prüfstand. Münster: Mentis (Brill), 2017, pp. 15-47; doi: 10.30965/9783957438393_003.
    Mentis (Brill)   Google Scholar   Abstract (40 KB)   pdf-download (196 KB)
  • DENKER, H.-W.:
    Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development.
    Cells 5(4): E39 (2016) (doi:10.3390/cells5040039)
    PubMed   Cells Website   pdf-download (5.16 MB)
  • DENKER, H.-W.:
    Implantation: Cell biology of embryo penetration route revisited.
    (Comment on: UCHIDA, H. et al.: How to create an embryo penetration route. Am. J. Reprod. Immunol. 75(3): 326-332, 2016; doi: 10.1111/aji.12476)
    Am. J. Reprod. Immunol. 76(6): 429-431 (2016) (doi: 10.1111/aji.12591).
    PubMed   AJRI   pdf-download (219 KB)   summary (68 KB)
  • DENKER, H.-W.:
    Comment on G. Herranz: The timing of monozygotic twinning: a criticism of the common model. Zygote (2013).
    (Comment on: HERRANZ, G.: Zygote 23(1): 27-40, 2015; doi: 10.1017/S0967199413000257)
    Zygote 23(2): 312-314 (2015) (doi: 10.1017/S0967199413000579).
    PubMed   Zygote   pdf-download (41.8 KB)
  • DENKER, H.-W.:
    A Quest for Refocussing Stem Cell Induction Strategies: How to Deal with Ethical Objections and Patenting Problems.
    In: M. Prasad and P. Di Nardo (Eds.): Innovative Strategies in Tissue Engineering. (River Publishers Series in Research and Business Chronicles: Biotechnology and Medicine; Vol. 2; A. Vertes, P. Di Nardo and P. Rameshwar, Ser.-Eds.) Aalborg, Denmark: River Publishers, 2015, pp. 117-134.
    Google Scholar   River Publishers   River Publishers (Open Access)   pdf-download (385 KB)
  • DENKER, H.-W.:
    Stem Cell Terminology and 'Synthetic' Embryos: A New Debate on Totipotency, Omnipotency, and Pluripotency and How It Relates to Recent Experimental Data
    Cells Tissues Organs 199: 221-227 (2014).
    PubMed   CTO Website (free access)
  • DENKER, H.-W.:
    Time to reconsider stem cell induction strategies.
    Cells 1: 1293-1312 (2012) (Open Access).
    PubMed   Cells Website   pdf-download (222 KB)
  • DENKER, H.-W., HOLM, S.:
    Patenting and stem cell pluripotency.
    (Comment on: SMITH, A.: 'No' to ban on stem-cell patents. Nature 472, 418, 2011; doi: 10.1038/472418a.)
    Nature 472: 418, 2011; Online Comment #22079.
    pdf-download (6.56 KB)   Nature Website
    Segregation during cleavage in the mammalian embryo? A critical comparison of whole-mount/CLSM and section immunohistochemistry casts doubts on segregation of axis-relevant leptin domains in the rabbit.
    Histochemistry and Cell Biology 135: 553-570 (2011).
    PubMed   SpringerLink

Recent unpublished Comments...

...on Publications (view all)

  • DENKER, H.-W.:
    „Totipotency“ of stem cells: Plasticity vs. self-organization capacity
    (Comment on: ISHIUCHI, T., ENRIQUEZ-GASCA, R., MIZUTANI, E., BOSKOVIC, A., ZIEGLER-BIRLING, C., RODRIGUEZ-TERRONES, D., WAKAYAMA, T., VAQUERIZAS, J.M., TORRES-PADILLA, M.E.: Early embryonic-like cells are induced by downregulating replication-dependent chromatin assembly. Nature Struct. Mol. Biol. 22: 662-671, 2015).
    pdf-download (113 KB)
  • DENKER, H.-W.:
    Comment on Draft NIH Guidelines for Human Stem Cell Research (2009) (Public Comment ID 16452).
    pdf-download (15.1 KB)   NIH WebsiteUnfortunately, NIH has removed this webpage.
    However, you are still welcome to download my comment as a PDF (15.1 KB).

...on Events (view all)

  • December 2012
    Stem Cell Patents: Ruling of the German Bundesgerichtshof (BGH) - a Missed Chance
    On 27 November 2012, the German Federal Court of Justice (Bundesgerichtshof, BGH) in Karlsruhe has finally ruled in the stem cell patenting case Greenpeace vs. Brüstle (background information)... [more]
  • November 2011
    Stem Cell Patents
    The European Court of Justice (ECJ) in Luxembourg ruled on October 18, 2011, that stem cells cannot be patented if their derivation involves/d sacrificing human embryos (as typical for the derivation of embryonic stem cells, ES cells)... [more]
  • April/May 2011
    Legislative initiatives concerning PID/PGD: Debates of the German Bundestag
    The German parliament (Bundestag) is presently discussing legislative initiatives for regulations of preimplantation diagnosis (PID/PGD)... [more]

...on Books (view all)

  • WEIGL, A.: Resch-Verlag (2007)
    Der preisgegebene Mensch. Überlegungen zum biotechnischen Umgang mit menschlichen Embryonen.

Recently added PDFs

  • DENKER, H.-W.:
    Formation of the blastocyst: determination of trophoblast and embryonic knot.
    Current Topics in Pathology (E. Grundmann und H.W. Kirsten, eds.) Vol. 62: Developmental Biology and Pathology (A. Gropp und K. Benirschke, Vol.-eds.). Berlin-Heidelberg-New York: Springer-Verlag, 1976, pp. 59-79.
    PubMed   SpringerLink   pdf-download (8.17 MB)   Abstract (58 KB)
  • DENKER, H.-W. and THIE, M.:
    The regulatory function of the uterine epithelium for trophoblast attachment: experimental approaches.
    In: Molecular, Cellular and Developmental Biology of Reproduction: Basic and Clinical Aspects (P.M. Motta, S.A. Nottola, G. Macchiarelli and S. Correr, Eds.).
    Italian Journal of Anatomy and Embryology 106 (2 Supplement 2): 291-306, 2001.
    pdf-download (12.2 MB) PubMed
  • DENKER, H.-W.:
    Embryonen und Embryoide: Gedanken eines Entwicklungsbiologen zu ethischen Implikationen von Autonomie und Machbarkeit.
    (Lecture) Der manipulierbare Embryo: Potentialitäts- und Speziesargumente auf dem Prüfstand (Auftakttagung zum BMBF-Projekt "Der manipulierbare Embryo"), Eichstätt, Katholische Universität Eichstätt-Ingolstadt, 3.-5. Nov. 2016.
    lecture pdf (4.70 MB)
    Die Geister, die sie riefen.
    Hintergründe der politischen Durchsetzung der Embryonennutzung – Eine Erforschung der Forscher.

    FAZ – Frankfurter Allgemeine Zeitung, Nr. 137, 16.06.2001, p. 41/43.
    FAZ-archive   pdf-download (548 KB, with kind permission of FAZ)

    A fascinating report on the highly politicised discussions about establishing stem cell research in Germany around 2001, addressing aspects that deserve increased attention again today, i.e. after the advent of cell reprogramming technologies, and since self-organization of stem cells is receiving much interest. This article specifically provides background information about the decision of my group to switch its focus of research, which had previously been on the cell biology of embryo implantation, to stem cell self-organization, and why it was impossible to complete this new research program in spite of, or perhaps due to, its ethical impact.

    Continued differentiation of mammalian embryos in utero after blockage of implantation.
    Abstract No. 22, XVth EDBO International Embryological Conference, Strasbourg, 1982
    abstract (376 KB)   poster (11.8 MB)

    This conference poster has now been scanned and is presented here in full length as PDF because the morphological findings that it documents have not been published in detail elsewhere. These data are of particular interest because they clearly contradict a widely held opinion that embryo implantation is an absolute prerequesite for the development of a basic body plan. This poster shows on contrast that, when hatching of rabbit embryos is prevented by proteinase inhibitor infusion into the uterus, differentiation of the embryonic anlage can continue at an only slightly reduced pace, in spite of the fact that implantation has been prevented and the embryo remains free-floating in the uterine lumen. The illustrations document in detail that basic elements of the basic body plan (like neural tube, somites) can be formed in a regular way in such non-implanted embryos.

    Shedding of the "capsule" and proteinase activity in the horse embryo.
    (Abstr.) IV Int. Sympos. on Equine Reproduction, Calgary 1986. J. Reprod. Fert. Suppl. 35, 703 (1987)
    pdf-download (366 KB)   poster (6.09 MB)

    This conference poster has been scanned and is presented here now in full lenghth as PDF because its photographs and data remained unique, i.e. they have not been published otherwise, and no comparable data are available in the literature. The reason is that it was not possible to continue this study on proteinases involved in horse embryo implantation, because additional specimens (of shock-frozen horse embryos within the uterus) representing the most interesting stages could not be obtained due to logistic and financial difficulties. So these data remain until today the only available details on proteolytic enzymes possibly involved in hatching of the horse embryo from its extracellular coverings/coat, the "capsule", in utero.