title: Time course of the meiotic arrest in sheep cumulus-oocyte complexes treated with roscovitine.
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 μM 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.
authors.affiliation: Rua dos Girassóis,n.278 - Bairro Convívio - CEP: 18605-240 Botucatu - S.P.,Brazil.
authors.forename: Letícia Ferrari
authors.initials: LF
authors.lastname: Crocomo
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology - School of Veterinary Medicine and Animal Science (FMVZ),São Paulo State University (UNESP) - Botucatu,Brazil.
authors.forename: Wolff Camargo
authors.initials: WC
authors.lastname: Marques Filho
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology - School of Veterinary Medicine and Animal Science (FMVZ),São Paulo State University (UNESP) - Botucatu,Brazil.
authors.forename: Camila Louise
authors.initials: CL
authors.lastname: Ackermann
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology - School of Veterinary Medicine and Animal Science (FMVZ),São Paulo State University (UNESP) - Botucatu,Brazil.
authors.forename: Daniela Martins
authors.initials: DM
authors.lastname: Paschoal
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology - School of Veterinary Medicine and Animal Science (FMVZ),São Paulo State University (UNESP) - Botucatu,Brazil.
authors.forename: Midyan Daroz
authors.initials: MD
authors.lastname: Guastali
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology - School of Veterinary Medicine and Animal Science (FMVZ),São Paulo State University (UNESP) - Botucatu,Brazil.
authors.forename: Rosiára Rosária
authors.initials: RR
authors.lastname: Dias Maziero
authors.affiliation: Laboratory of Genetics and Animal Breeding,Federal University of Pampa,Uruguaiana,RS,Brazil.
authors.forename: Mateus José
authors.initials: MJ
authors.lastname: Sudano
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology - School of Veterinary Medicine and Animal Science (FMVZ),São Paulo State University (UNESP) - Botucatu,Brazil.
authors.forename: Fernanda da Cruz
authors.initials: Fda C
authors.lastname: Landim-Alvarenga
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology - School of Veterinary Medicine and Animal Science (FMVZ),São Paulo State University (UNESP) - Botucatu,Brazil.
authors.forename: Sony Dimas
authors.initials: SD
authors.lastname: Bicudo
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D054885:Cumulus Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods; D007986:Luteinizing Hormone / Q000494:pharmacology; D008540:Meiosis / Q000187:drug effects*; D009865:Oocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011687:Purines / Q000494:pharmacology*; D000077546:Roscovitine; D012756:Sheep; D013997:Time Factors
chemical_list: D047428:Protein Kinase Inhibitors; D011687:Purines; D000077546:Roscovitine; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D018844:Cyclin-Dependent Kinases
keywords: Cumulus cell expansion; Inhibitor; Meiosis; Nuclear maturation; Ovine