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This Article Full Text Full Text (PDF) All Versions of this Article: 36/2/98    most recent 90310.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Léandri, R. D. Articles by Duranthon, V. PubMed PubMed Citation Articles by Léandri, R. D. Articles by Duranthon, V.

Revealing the dynamics of gene expression during embryonic genome activation and first differentiation in the rabbit embryo with a dedicated array screening

¹ INRA UMR 1198, Biologie du Développement et Reproduction, Jouy-en-Josas, France
² Agenae, Unité Mathématique, Informatique et Génome, Jouy-en-Josas, France
³ UMR INRA/CEA Radiobiologie et Etude du Génome/Centre de Ressources Biologiques pour la Génomique des Animaux d'Elevages et d'Intérêt Economique, Jouy-en-Josas, France

Early mammalian development is characterized by extensive changes in nuclear functions that result from epigenetic modifications of the newly formed embryonic genome. While the first embryonic cells are totipotent, this status spans only a few cell cycles. At the blastocyst stage, the embryo already contains differentiated trophectoderm cells and pluripotent inner cell mass cells. Concomitantly, the embryonic genome becomes progressively transcriptionally active. During this unique period of development, the gene expression pattern has been mainly characterized in the mouse, in which embryonic genome activation (EGA) spans a single cell cycle after abrupt epigenetic modifications. To further characterize this period, we chose to analyze it in the rabbit, in which, as in most mammals, EGA is more progressive and occurs closer to the first cell differentiation events. In this species, for which no transcriptomic arrays were available, we focused on genes expressed at EGA and first differentiation and established a 2,000-gene dedicated cDNA array. Screening this with pre-EGA, early post-EGA, and blastocyst embryos divided genes into seven clusters of expression according to their regulation during this period and revealed their dynamics of expression during EGA and first differentiation. Our results point to transient properties of embryo transcriptome at EGA, due not only to the transition between maternal and embryonic transcripts but also to the transient expression of a subset of embryonic genes whose functions remained largely uncharacterized. They also provide a first view of the functional consequences of the changes in gene expression program.

blastocyst; morula; transient expression; maternal embryo transition