title: Oct-4 regulates the expression of Stella and Foxj2 at the Nanog locus: implications for the developmental competence of mouse oocytes.
abstract: BACKGROUND
  Our knowledge of what determines the mammalian oocyte developmental competence is meagre. By comparing the transcriptional profiles of developmentally competent surrounded nucleolus (SN) and incompetent not surrounded nucleolus (NSN) mouse MII oocytes, we recently demonstrated that Oct-4 and Stella are key factors in the establishment of the oocytes' developmental competence.
  
  
  METHODS
  Using RT-PCR, microarray and immunocytochemistry assays, we analysed expression of genes and proteins in oocytes isolated throughout folliculogenesis and classified based on their SN- or NSN-type of chromatin organization.
  
  
  RESULTS
  We show that: (1) Oct-4 and Stella are expressed concurrently at the beginning of oocytes' growth and only in SN oocytes; (2) Germ Cell Nuclear Factor is a putative regulator of Oct-4 expression in MII oocytes; (3) the function of Oct-4 is directed at the Nanog locus, regulating the expression of Stella and Foxj2.
  
  
  CONCLUSIONS
  (1) A number of factors that act upstream and downstream of Oct-4 emerge as candidate players in the acquisition of the oocyte's developmental competence; (2) we define molecular markers that identify a specific group of ovarian oocytes (SN) that have a potential to acquire developmental competence; (3) the presence of SN and NSN oocytes in human ovaries extends the interest of these results to the field of human reproduction.
authors.affiliation: Sezione di Istologia ed Embriologia, Dipartimento di Medicina Sperimentale, Universita' degli Studi di Parma, Via Volturno 39, 43100 Parma, Italy. maurizio.zuccotti@unipr.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Zuccotti
authors.forename: Valeria
authors.initials: V
authors.lastname: Merico
authors.forename: Lucia
authors.initials: L
authors.lastname: Sacchi
authors.forename: Michele
authors.initials: M
authors.lastname: Bellone
authors.forename: Thore C
authors.initials: TC
authors.lastname: Brink
authors.forename: Mario
authors.initials: M
authors.lastname: Stefanelli
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Redi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Bellazzi
authors.forename: James
authors.initials: J
authors.lastname: Adjaye
authors.forename: Silvia
authors.initials: S
authors.lastname: Garagna
mesh_terms: D000818:Animals; D002868:Chromosomal Proteins, Non-Histone; D015536:Down-Regulation; D005260:Female; D051858:Forkhead Transcription Factors / Q000096:biosynthesis; D018398:Homeodomain Proteins / Q000502:physiology; D051379:Mice; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000502:physiology*; D009865:Oocytes / Q000502:physiology*; D009866:Oogenesis / Q000235:genetics; D012097:Repressor Proteins / Q000096:biosynthesis; D015854:Up-Regulation
chemical_list: D002868:Chromosomal Proteins, Non-Histone; C462180:Dppa3 protein, mouse; D051858:Forkhead Transcription Factors; C485809:Foxj2 protein, mouse; D018398:Homeodomain Proteins; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D050814:Octamer Transcription Factor-3; D012097:Repressor Proteins