title: Development of the follicular basement membrane during human gametogenesis and early folliculogenesis.
abstract: BACKGROUND
  In society, there is a clear need to improve the success rate of techniques to restore fertility. Therefore a deeper knowledge of the dynamics of the complex molecular environment that regulates human gametogenesis and (early) folliculogenesis in vivo is necessary. Here, we have studied these processes focusing on the formation of the follicular basement membrane (BM) in vivo.
  
  
  RESULTS
  The distribution of the main components of the extracellular matrix (ECM) collagen IV, laminin and fibronectin by week 10 of gestation (W10) in the ovarian cortex revealed the existence of ovarian cords and of a distinct mesenchymal compartment, resembling the organization in the male gonads. By W17, the first primordial follicles were assembled individually in that (cortical) mesenchymal compartment and were already encapsulated by a BM of collagen IV and laminin, but not fibronectin. In adults, in the primary and secondary follicles, collagen IV, laminin and to a lesser extent fibronectin were prominent in the follicular BM.
  
  
  CONCLUSIONS
  The ECM-molecular niche compartimentalizes the female gonads from the time of germ cell colonization until adulthood. This knowledge may contribute to improve methods to recreate the environment needed for successful folliculogenesis in vitro and that would benefit a large number of infertility patients.
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333, Leiden, ZC, The Netherlands. marijneheeren@gmail.com.|Department of Gynaecology, Leiden University Medical Center, Albinusdreef 2, 2300, Leiden, RC, The Netherlands. marijneheeren@gmail.com.|Current address: Department of Obstetrics and Gynaecology, VU University Medical Center, De Boelelaan 1118, 1081, Amsterdam, HZ, The Netherlands. marijneheeren@gmail.com.
authors.forename: A Marijne
authors.initials: AM
authors.lastname: Heeren
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333, Leiden, ZC, The Netherlands. L.van_Iperen@lumc.nl.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: van Iperen
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333, Leiden, ZC, The Netherlands. danielle.k90@gmail.com.
authors.forename: Daniëlle B
authors.initials: DB
authors.lastname: Klootwijk
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333, Leiden, ZC, The Netherlands. A.B.de_Melo_Bernardo@lumc.nl.
authors.forename: Ana
authors.initials: A
authors.lastname: de Melo Bernardo
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333, Leiden, ZC, The Netherlands. M.S.Roost@lumc.nl.
authors.forename: Matthias S
authors.initials: MS
authors.lastname: Roost
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333, Leiden, ZC, The Netherlands. M.M.Gomes_Fernandes@lumc.nl.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Gomes Fernandes
authors.affiliation: Department of Gynaecology, Leiden University Medical Center, Albinusdreef 2, 2300, Leiden, RC, The Netherlands. L.A.Louwe@lumc.nl.
authors.forename: Leonie A
authors.initials: LA
authors.lastname: Louwe
authors.affiliation: Department of Gynaecology, Reinier de Graaf Hospital, Reinier de Graaf 3-11, 2625, Delft, AD, The Netherlands. Hilders@rdgg.nl.
authors.forename: Carina G
authors.initials: CG
authors.lastname: Hilders
authors.affiliation: Department of Gynaecology, Leiden University Medical Center, Albinusdreef 2, 2300, Leiden, RC, The Netherlands. F.M.Helmerhorst@lumc.nl.
authors.forename: Frans M
authors.initials: FM
authors.lastname: Helmerhorst
authors.affiliation: Department of Gynaecology, Leiden University Medical Center, Albinusdreef 2, 2300, Leiden, RC, The Netherlands. L.A.J.van_der_Westerlaken@lumc.nl.
authors.forename: Lucette A J
authors.initials: LA
authors.lastname: van der Westerlaken
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333, Leiden, ZC, The Netherlands. lopes@lumc.nl.|Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium. lopes@lumc.nl.
authors.forename: Susana M
authors.initials: SM
authors.lastname: Chuva de Sousa Lopes
mesh_terms: D001485:Basement Membrane / Q000378:metabolism / Q000502:physiology*; D024141:Collagen Type IV / Q000378:metabolism; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D005718:Gametogenesis; D006801:Humans; D008297:Male; D006080:Ovarian Follicle / Q000254:growth & development*; D010053:Ovary / Q000196:embryology / Q000378:metabolism; D013737:Testis / Q000196:embryology / Q000378:metabolism
chemical_list: D024141:Collagen Type IV; D005353:Fibronectins