title: H3K9 trimethylation precedes DNA methylation during sheep oogenesis: HDAC1, SUV39H1, G9a, HP1, and Dnmts are involved in these epigenetic events.
abstract: The oocyte, to become a fully mature gamete, has to acquire a correct pattern of DNA methylation on its genome; this epigenetic event represents the major point of the molecular mechanisms that occur during postnatal oogenesis. It is known that an intimate link exists between DNA methylation and histone posttranslational modifications, such as trimethylation of lysine 9 on histone 3 (H3K9me3), that is essential in the silencing of gene transcription. What remains unclear is the precise sequence of these two epigenetic events and the protein expression of the enzymes that catalyze this epigenetic maturation during oogenesis. To identify the key molecules involved in global DNA methylation and H3K9me3, a biological network-based computational model was realized. Then, the spatiotemporal distribution of the proteins, identified from the biological network, was assessed during postnatal oogenesis. The results obtained suggest the existence of a sequential cascade of events in which H3K9me3 is the primary step followed by DNA methylation. These two epigenetic marks are realized due to the recruitment of the HDAC1, SUV39H1, G9a, HP1, and Dnmt3a, which were always localized in the nuclei of the oocytes and were dependent on chromatin configuration. These results involving DNA methylation and H3K9me3 are crucial in defining the oocyte developmental competence.
authors.affiliation: Department of Comparative Biomedical Sciences, University of Teramo, Teramo, Italy. vrusso@unite.it
authors.forename: Valentina
authors.initials: V
authors.lastname: Russo
authors.forename: Nicola
authors.initials: N
authors.lastname: Bernabò
authors.forename: Oriana
authors.initials: O
authors.lastname: Di Giacinto
authors.forename: Alessandra
authors.initials: A
authors.lastname: Martelli
authors.forename: Annunziata
authors.initials: A
authors.lastname: Mauro
authors.forename: Paolo
authors.initials: P
authors.lastname: Berardinelli
authors.forename: Valentina
authors.initials: V
authors.lastname: Curini
authors.forename: Delia
authors.initials: D
authors.lastname: Nardinocchi
authors.forename: Mauro
authors.initials: M
authors.lastname: Mattioli
authors.forename: Barbara
authors.initials: B
authors.lastname: Barboni
mesh_terms: D000818:Animals; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D003198:Computer Simulation; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D019175:DNA Methylation; D000090205:DNA Methyltransferase 3A; D044127:Epigenesis, Genetic; D056284:Histone Deacetylase 1 / Q000378:metabolism*; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D007150:Immunohistochemistry; D008239:Lysine / Q000378:metabolism; D008745:Methylation; D009866:Oogenesis; D012756:Sheep
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D000090266:Chromobox Protein Homolog 5; D000076983:Histone Methyltransferases; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D011495:Histone-Lysine N-Methyltransferase; D056284:Histone Deacetylase 1; D008239:Lysine