title: Messenger RNAs in metaphase II oocytes correlate with successful embryo development to the blastocyst stage.
abstract: The mRNAs accumulated in oocytes provide support for embryo development until embryo genomic activation. We hypothesized that the maternal mRNA stock present in bovine oocytes is associated with embryo development until the blastocyst stage. To test our hypothesis, we analyzed the transcriptome of the oocyte and correlated the results with the embryo development. Our goal was to identify genes expressed in the oocyte that correlate with its ability to develop to the blastocyst stage. A fraction of oocyte cytoplasm was biopsied using micro-aspiration and stored for further expression analysis. Oocytes were activated chemically, cultured individually and classified according to their capacity to develop in vitro to the blastocyst stage. Microarray analysis was performed on mRNA extracted from the oocyte cytoplasm fractions and correlated with its ability to develop to the blastocyst stage (good quality oocyte) or arrest at the 8-16-cell stage (bad quality oocyte). The expression of 4320 annotated genes was detected in the fractions of cytoplasm that had been collected from oocytes matured in vitro. Gene ontology classification revealed that enriched gene expression of genes was associated with certain biological processes: 'RNA processing', 'translation' and 'mRNA metabolic process'. Genes that are important to the molecular functions of 'RNA binding' and 'translation factor activity, RNA binding' were also enriched in oocytes. We identified 29 genes with differential expression between the two groups of oocytes compared (good versus bad quality). The content of mRNAs expressed in metaphase II oocytes influences the activation of the embryonic genome and enables further develop to the blastocyst stage.
authors.affiliation: Departamento de Genética, Faculdade de Medicina de Ribeirão Preto-Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.
authors.forename: Fernando Henrique
authors.initials: FH
authors.lastname: Biase
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, USA.
authors.forename: Robin Edward
authors.initials: RE
authors.lastname: Everts
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, USA.
authors.forename: Rosane
authors.initials: R
authors.lastname: Oliveira
authors.affiliation: Departamento de Ciências Básicas, Faculdade de Zootecnia e Engenharia de Alimentos-Universidade de São Paulo, Pirassununga, São Paulo, Brasil.
authors.forename: Weruska Karyna Freitas
authors.initials: WK
authors.lastname: Santos-Biase
authors.affiliation: Departamento de Ciências Básicas, Faculdade de Zootecnia e Engenharia de Alimentos-Universidade de São Paulo, Pirassununga, São Paulo, Brasil.
authors.forename: Giovana Krempel
authors.initials: GK
authors.lastname: Fonseca Merighe
authors.affiliation: Centre de Recherche en Reproducion Animale, Faculté de Médicine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada.
authors.forename: Lawrence Charles
authors.initials: LC
authors.lastname: Smith
authors.affiliation: Departamento de Genética, Faculdade de Medicina de Ribeirão Preto-Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.
authors.forename: Lúcia
authors.initials: L
authors.lastname: Martelli
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, USA.
authors.forename: Harris
authors.initials: H
authors.lastname: Lewin
authors.affiliation: Departamento de Ciências Básicas, Faculdade de Zootecnia e Engenharia de Alimentos-Universidade de São Paulo, Pirassununga, São Paulo, Brasil.
authors.forename: Flávio Vieira
authors.initials: FV
authors.lastname: Meirelles
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology* / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology* / Q000378:metabolism; D047108:Embryonic Development; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D066298:In Vitro Techniques; D008677:Metaphase / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D023121:RNA, Messenger, Stored / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D023121:RNA, Messenger, Stored