title: Effect of growth factors on oocyte maturation and allocations of inner cell mass and trophectoderm cells of cloned bovine embryos.
abstract: This study was conducted to determine the additive effects of exogenous growth factors during in vitro oocyte maturation (IVM) and the sequential culture of nuclear transfer (NT) embryos. Oocyte maturation and culture of reconstructed embryos derived from bovine granulosa cells were performed in culture medium supplemented with either epidermal growth factor (EGF) alone or a combination of EGF with insulin-like growth factor-I (IGF-I). The maturation rates of oocytes matured in the presence of EGF or the EGF + IGF-I combination were significantly higher than those of oocytes matured in the presence of only fetal calf serum (FCS) (P 0.05). IGF-I alone or in combination with EGF in sequential embryo culture medium significantly increased the ratio of inner cell mass (ICM) to total blastocyst cells (P < 0.05). Our results showed that the addition of growth factors to IVM and sequential culture media of cloned bovine embryos increased the ICM without changing the total cell number. These unknown and uncontrolled effects of growth factors can alter the allocation of ICM and trophectoderm cells (TE) in NT embryos. A decrease in TE cell numbers could be a reason for developmental abnormalities in embryos in the cloning system.
authors.affiliation: Namik Kemal University, Faculty of Agriculture,Department of Agricultural Biotechnology,Tekirdag,Turkey.
authors.forename: Sezen
authors.initials: S
authors.lastname: Arat
authors.affiliation: The Scientific and Technological Research Council of Turkey (TUBITAK),Marmara Research Center (MRC),Genetic Engineering and Biotechnology Institute,41470,Gebze,Kocaeli,Turkey.
authors.forename: Arzu Tas
authors.initials: AT
authors.lastname: Caputcu
authors.affiliation: Ondokuz Mayis University,Faculty of Veterinary Medicine,Department of Reproduction and Artificial Insemination,55200,Samsun,Turkey.
authors.forename: Mesut
authors.initials: M
authors.lastname: Cevik
authors.affiliation: The Scientific and Technological Research Council of Turkey (TUBITAK),Marmara Research Center (MRC),Genetic Engineering and Biotechnology Institute,41470,Gebze,Kocaeli,Turkey.
authors.forename: Tolga
authors.initials: T
authors.lastname: Akkoc
authors.affiliation: The Scientific and Technological Research Council of Turkey (TUBITAK),Marmara Research Center (MRC),Genetic Engineering and Biotechnology Institute,41470,Gebze,Kocaeli,Turkey.
authors.forename: Gaye
authors.initials: G
authors.lastname: Cetinkaya
authors.affiliation: Adiyaman University,Faculty of Medicine,Department of Medical Genetics,Adiyaman,Turkey.
authors.forename: Haydar
authors.initials: H
authors.lastname: Bagis
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D053624:Blastocyst Inner Cell Mass / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D002417:Cattle; D002478:Cells, Cultured; D019976:Cloning, Organism; D003470:Culture Media / Q000494:pharmacology; D004357:Drug Synergism; D047108:Embryonic Development / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D059471:In Vitro Oocyte Maturation Techniques; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
chemical_list: D003470:Culture Media; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I
keywords: Bovine; Cell allocation; Cloning; Embryo culture; Growth factors