title: Treatment of nuclear-donor cells or cloned zygotes with chromatin-modifying agents increases histone acetylation but does not improve full-term development of cloned cattle.
abstract: Although somatic cell nuclear transfer (SCNT) is a promising tool, its potential use is hampered by the high mortality rates during the development to term of cloned offspring. Abnormal epigenetic reprogramming of donor nuclei after SCNT is thought to be the main cause of this low efficiency. We hypothesized that chromatin-modifying agents (CMAs) targeting chromatin acetylation and DNA methylation could alter the chromatin configuration and turn them more amenable to reprogramming. Thus, bovine fibroblasts were treated with 5-aza-2'-deoxycytidine (AZA) plus trichostatin (TSA) or hydralazine (HH) plus valproic acid (VPA) whereas, in another trial, cloned bovine zygotes were treated with TSA. The treatment of fibroblasts with either AZA+TSA or HH+VPA increased histone acetylation, but did not affect the level of DNA methylation. However, treatment with HH+VPA decreased cellular viability and proliferation. The use of these cells as nuclear donors showed no positive effect on pre- and postimplantation development. Regarding the treatment of cloned zygotes with TSA, treated one-cell embryos showed an increase in the acetylation patterns, but not in the level of DNA methylation. Moreover, this treatment revealed no positive effect on pre- and postimplantation development. This work provides evidence the treatment of either nuclear donor cells or cloned zygotes with CMAs has no positive effect on pre- and postimplantation development of cloned cattle.
authors.affiliation: Departamento de Ciências Básicas, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Pirassununga, São Paulo, Brazil.
authors.forename: Juliano Rodrigues
authors.initials: JR
authors.lastname: Sangalli
authors.forename: Tiago Henrique Camara
authors.initials: TH
authors.lastname: De Bem
authors.forename: Felipe
authors.initials: F
authors.lastname: Perecin
authors.forename: Marcos Roberto
authors.initials: MR
authors.lastname: Chiaratti
authors.forename: Lilian de Jesus
authors.initials: Lde J
authors.lastname: Oliveira
authors.forename: Reno Roldi
authors.initials: RR
authors.lastname: de Araújo
authors.forename: José Rodrigo
authors.initials: JR
authors.lastname: Valim Pimentel
authors.forename: Lawrence Charles
authors.initials: LC
authors.lastname: Smith
authors.forename: Flávio Vieira
authors.initials: FV
authors.lastname: Meirelles
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000818:Animals; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D002417:Cattle / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D042002:Chromatin Assembly and Disassembly / Q000187:drug effects*; D019976:Cloning, Organism / Q000379:methods*; D000077209:Decitabine; D047108:Embryonic Development / Q000187:drug effects*; D005260:Female; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006657:Histones / Q000378:metabolism; D006830:Hydralazine / Q000494:pharmacology; D006877:Hydroxamic Acids / Q000494:pharmacology; D053652:Nuclear Transfer Techniques / Q000662:veterinary; D011247:Pregnancy; D047929:Term Birth / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D014635:Valproic Acid / Q000494:pharmacology; D015053:Zygote / Q000187:drug effects* / Q000502:physiology
chemical_list: D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D006830:Hydralazine; C012589:trichostatin A; D014635:Valproic Acid; D000077209:Decitabine; D001374:Azacitidine