Time course of the meiotic arrest in sheep cumulus-oocyte complexes treated with roscovitine

Author(s)

Crocomo, Leticia Ferrari ^[1] ; Marques Filho, Wolff Camargo ^[1] ; Ackermann, Camila Louise ^[1] ; Paschoal, Daniela Martins ^[1] ; Guastali, Midyan Daroz ^[1] ; Dias Maziero, Rosiara Rosaria ^[1] ; Sudano, Mateus Jose ^[2] ; Landim-Alvarenga, Fernanda da Cruz ^[1] ; Bicudo, Sony Dimas ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Dept Anim Reprod & Vet Radiol, Sch Vet Med & Anim Sci FMVZ, Botucatu, SP - Brazil

^[2] Fed Univ Pampa, Lab Genet & Anim Breeding, Uruguaiana, RS - Brazil

• Document type: Journal article
• Source: ZYGOTE; v. 24, n. 2, p. 310-318, APR 2016.
• Web of Science Citations: 2

Abstract

Temporary meiosis arrest with cyclin-dependent kinases inhibitors has been proposed in order to improve the quality of in vitro matured oocytes. In sheep, however, this phenomenon has been rarely investigated. Therefore, the present study aimed to evaluate the effect of different incubation times with roscovitine on nuclear maturation and cumulus cell expansion of sheep cumulus-oocyte complexes (COCs). For this, COCs were cultured for 0, 6, 12 or 20 h in basic maturation medium (Control) containing 75 M roscovitine (Rosco). After, they were in vitro matured (IVM) for 18 h in the presence of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). At the end of each treatment, cumulus cell expansion and nuclear maturation were assessed under a stereomicroscope and by Hoechst 33342 staining, respectively. In the Control and Rosco groups, the absence of cumulus cell expansion prevailed at 0, 6, 12 and 20 h. After IVM for 18 h, total cumulus cell expansion in the Rosco treatments was dependent on the exposure time to roscovitine. A significantly high percentage of oocytes treated with roscovitine for 6 h (87%), 12 h or 20 h (65%) were arrested at the germinal vesicle (GV) stage. In contrast, 23% GVBD, 54% metaphase I (MI) and 61% MII oocytes were observed in the Control groups at 6, 12 and 20 h, respectively. In all treatments, a significant percentage of oocytes reached MII after IVM for 18 h. Therefore, roscovitine reversibly arrested the meiosis of sheep oocytes during different culture times with the maximal efficiency of meiotic inhibition reached at 6 h. In addition, reversibility of its inhibitory action on cumulus cells was exposure-time dependent. (AU)

• FAPESP's process: 11/18843-9 - Gene expression and in vitro developmental potential of sheep cumulus-oocyte complexes treated with roscovitine
• Grantee: Sony Dimas Bicudo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/14041-5 - Gene expression and in vitro developmental potential of sheep cumulus-oocyte complexes treated with roscovitine
• Grantee: Letícia Ferrari Crocomo
• Support Opportunities: Scholarships in Brazil - Doctorate