title: Epigenetic Status of H19-Igf2 Imprinted Genes and Loss of 5-Hydroxymethylcytosine in the Brain of Cloned Goats.
abstract: In mammals, the imprinted genes play vital roles in development and are generally controlled by DNA methylation at imprinting control regions (ICRs). Recently, it was discovered that 5-hydroxymethylcytosine (5-hmC) is a stable epigenetic modification; however, its functions in cloned animal genomes have not yet been fully elucidated. In this study, we interrogated and quantified the 5-hmC levels in the brain of cloned goats and discovered upregulation of Uhrf1 (p < 0.001), Dnmt1 (p < 0.05), Dnmt3a (p < 0.05), Igf2 (p < 0.01), and H19 (p < 0.05) and downregulation of Dnmt3b (p < 0.001), Tet1 (p < 0.001), Tet2 (p < 0.05), Tet3 (p < 0.001), Mecp2 (p < 0.05), and Igf2r (p < 0.05) in deceased cloned goat tissues compared with the normal controls. We demonstrated that DNA methylation was increased at H19 ICR (51.33% ± 2.03% vs. 93.07% ± 3.06%; p < 0.01) and that DNA was hypomethylated at Igf2 ICR (4.57% ± 1.48% vs. 7.63% ± 1.83%; p > 0.05) in the brain of deceased cloned goats. Finally, we showed that within the cloned goat brain genome, the amount of genome-wide 5-hmC was significantly decreased (0.083% ± 0.026% vs. 0.024% ± 0.007%; p < 0.05), whereas the 5-hmC levels within H19 and Igf2 CCGG sites were not significantly altered (0.17% ± 0.09% vs. 0.03% ± 0.01%; p > 0.05) in the brain of deceased cloned goats. Our data bring further experimental evidence regarding the abnormalities in 5-hmC and advance our current understanding of the role of 5-hmC in cloned animals.
authors.affiliation: Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University , Nanjing, China.
authors.forename: Mingtian
authors.initials: M
authors.lastname: Deng
authors.affiliation: Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University , Nanjing, China.
authors.forename: Caifang
authors.initials: C
authors.lastname: Ren
authors.affiliation: Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University , Nanjing, China.
authors.forename: Zifei
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University , Nanjing, China.
authors.forename: Guomin
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University , Nanjing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University , Nanjing, China.
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Wan
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D019976:Cloning, Organism; D019175:DNA Methylation; D005260:Female; D018392:Genomic Imprinting; D006041:Goats / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism*; D008297:Male
chemical_list: D006657:Histones; C011865:5-hydroxymethylcytosine; D007335:Insulin-Like Growth Factor II; D044503:5-Methylcytosine
keywords: 5-hydroxymethylcytosine; DNA methylation; goat; imprinting; somatic cell nuclear transfer