title: Time-lapse dynamics of the mouse oocyte chromatin organisation during meiotic resumption.
abstract: In the mammalian oocyte, distinct patterns of centromeres and pericentromeric heterochromatin localisation correlate with the gamete's developmental competence. Mouse antral oocytes display two main types of chromatin organisation: SN oocytes, with a ring of Hoechst-positive chromatin surrounding the nucleolus, and NSN oocytes lacking this ring. When matured to MII and fertilised, only SN oocytes develop beyond the 2-cell, and reach full term. To give detailed information on the dynamics of the SN or NSN chromatin during meiosis resumption, we performed a 9 hr time-lapse observation. The main significant differences recorded are: (1) reduction of the nuclear area only in SN oocytes; (2) ~17 min delay of GVBD in NSN oocytes; (3) chromatin condensation, after GVBD, in SN oocytes; (4) formation of 4-5 CHCs in SN oocytes; (5) increase of the perivitelline space, ~57 min later in NSN oocytes; (6) formation of a rosette-like disposition of CHCs, ~84 min later in SN oocytes; (7) appearance of the MI plate ~40 min later in NSN oocytes. Overall, we described a pathway of transition from the GV to the MII stage that is punctuated of discrete recordable events showing their specificity and occurring with different time kinetics in the two types of oocytes.
authors.affiliation: Laboratorio di Biologia dello Sviluppo, Dipartimento di Biologia e Biotecnologie "Lazzaro Spallanzani", Università degli Studi di Pavia, Via Ferrata 9, 27100 Pavia, Italy.
authors.forename: Martina
authors.identifier: 0000-0003-1926-6709
authors.initials: M
authors.lastname: Belli
authors.affiliation: Laboratorio di Biologia dello Sviluppo, Dipartimento di Biologia e Biotecnologie "Lazzaro Spallanzani", Università degli Studi di Pavia, Via Ferrata 9, 27100 Pavia, Italy.
authors.forename: Giulia
authors.identifier: 0000-0002-2864-4604
authors.initials: G
authors.lastname: Vigone
authors.affiliation: Laboratorio di Biologia dello Sviluppo, Dipartimento di Biologia e Biotecnologie "Lazzaro Spallanzani", Università degli Studi di Pavia, Via Ferrata 9, 27100 Pavia, Italy.
authors.forename: Valeria
authors.identifier: 0000-0002-3872-259X
authors.initials: V
authors.lastname: Merico
authors.affiliation: Laboratorio di Biologia dello Sviluppo, Dipartimento di Biologia e Biotecnologie "Lazzaro Spallanzani", Università degli Studi di Pavia, Via Ferrata 9, 27100 Pavia, Italy ; Centro Ricerche di Medicina Rigenerativa, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy.
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Redi
authors.affiliation: Laboratorio di Biologia dello Sviluppo, Dipartimento di Biologia e Biotecnologie "Lazzaro Spallanzani", Università degli Studi di Pavia, Via Ferrata 9, 27100 Pavia, Italy ; Centro di Ingegneria Tissutale, Università degli Studi di Pavia, 27100 Pavia, Italy.
authors.forename: Silvia
authors.identifier: 0000-0003-0803-2405
authors.initials: S
authors.lastname: Garagna
authors.affiliation: Sezione di Anatomia, Istologia ed Embriologia, Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali (S.Bi.Bi.T.), Università degli Studi di Parma, Via Volturno 39, 43125 Parma, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Zuccotti
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism*; D005260:Female; D008540:Meiosis; D051379:Mice; D009865:Oocytes / Q000166:cytology*; D013997:Time Factors; D059008:Time-Lapse Imaging / Q000379:methods*
chemical_list: D002843:Chromatin