title: Germ cells influence cord formation and Leydig cell gene expression during mouse testis development.
abstract: BACKGROUND
  It is widely accepted that, during the development of testes in the mammalian embryo, male germ cells are influenced by signals from the surrounding somatic cells, but not vice versa, so that germ cells are dispensable for the formation of testes.
  
  
  RESULTS
  We now demonstrate that development of the mouse fetal testis is compromised in the absence of germ cells. Using two- and three-dimensional imaging techniques, we reveal that W(e)/W(e) mutant testes devoid of germ cells have misshapen and poorly organized cords. We also found that mutant gonads have fewer Sertoli cells than normal and that the Leydig cells express key markers at higher than normal levels.
  
  
  CONCLUSIONS
  These observations point to the existence of germ cell-derived signals that directly or indirectly affect the Sertoli and Leydig cell populations, and provide a new paradigm for the organogenesis of the mammalian testes.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Rios-Rojas
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
authors.forename: Cassy
authors.initials: C
authors.lastname: Spiller
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
authors.forename: Josephine
authors.initials: J
authors.lastname: Bowles
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Koopman
mesh_terms: D000818:Animals; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005854:Germ Cells / Q000378:metabolism*; D007985:Leydig Cells / Q000378:metabolism*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D013085:Spermatic Cord / Q000196:embryology*
keywords: morphogenesis; organogenesis; sex determination; signaling; testosterone