title: Oct4-GFP expression during transformation of gonocytes into spermatogonial stem cells in the perinatal mouse testis.
abstract: OBJECTIVE
  In cryptorchidism perinatal failure to switch off Oct4, a germ cell (GC) marker, may lead to carcinoma in situ. We aimed to analyze Oct4 expression during mouse gonocyte transformation into spermatogonial stem cells (SSC).
  
  
  METHODS
  Testes from OG2 (Oct4-promoter driven eGFP) mice at embryonic day (E) 17 and postnatal day P0-10 underwent immunohistochemistry and immunoblotting. Antibodies against MVH, AMH, Ki67, and c-Kit were visualized by confocal microscopy. Numbers of Oct4-GFP(+) GC and Oct4-GFP(-) GC/tubule were counted using ImageJ. Data were analyzed using nonparametric one-way ANOVA.
  
  
  RESULTS
  GC from E17-P4 were Oct4-GFP(+). Numbers of Oct4-GFP(-) GC/tubule increased from P6-10, whereas Oct4-GFP(+) GC/tubule numbers remained similar between P6 and P10. Sertoli cells proliferated from E17-P10, whereas GC only proliferated from P2. Gonocytes (Oct4-GFP(+)/c-Kit(-)) central in tubules migrated to the basement membrane to become prospermatogonia (Oct4-GFP(+)/c-Kit(-)) and then SSC (Oct4-GFP(+)/c-Kit(+)) from day 4 and further developed into Oct4-GFP(-)/c-Kit(+) at P6.
  
  
  CONCLUSIONS
  In Oct4-GFP mice both centrally located gonocytes and prospermatogonia located at the tubular basement membrane were Oct4-GFP(+)/c-Kit(-) before further developing into SSC (Oct4-GFP(+)/c-Kit(+)). This indicates that Oct4 is important in gonocyte transformation into SSC. Understanding this process will aid GC tumor diagnostics and fertility potential in boys with UDT undergoing orchidopexy.
authors.affiliation: FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC 3052, Australia. Electronic address: ruili.li@mcri.edu.au.
authors.forename: Ruili
authors.initials: R
authors.lastname: Li
authors.affiliation: FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia.
authors.forename: Amanda
authors.initials: A
authors.lastname: Vannitamby
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhang
authors.affiliation: Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC 3800, Australia.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Fehmel
authors.affiliation: FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC 3052, Australia.
authors.forename: Bridget R
authors.initials: BR
authors.lastname: Southwell
authors.affiliation: FD Stephens Surgical Research Group, Murdoch Childrens Research Institute, Parkville, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC 3052, Australia; Urology Department, The Royal Children's Hospital, Parkville, VIC 3052, Australia. Electronic address: john.hutson@rch.org.au.
authors.forename: John M
authors.initials: JM
authors.lastname: Hutson
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000166:cytology; D002454:Cell Differentiation; D002465:Cell Movement; D049109:Cell Proliferation; D003456:Cryptorchidism / Q000473:pathology; D005854:Germ Cells / Q000166:cytology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D050814:Octamer Transcription Factor-3 / Q000378:metabolism*; D012708:Sertoli Cells / Q000166:cytology; D013093:Spermatogonia / Q000166:cytology* / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism*
chemical_list: D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse
keywords: Gonocyte migration; Gonocytes transformation; Oct4; Spermatogonial stem cells; Undescended testis