Transcript profiling during preimplantation mouse development

Abstract

Studies using low-resolution methods to assess gene expression during preimplantation mouse development indicate that changes in gene expression either precede or occur concomitantly with the major morphological transitions, that is, conversion of the oocyte to totipotent 2-cell blastomeres, compaction, and blastocyst formation. Using microarrays, we characterized global changes in gene expression and used Expression Analysis Systematic Explorer (EASE) to identify biological and molecular processes that accompany and likely underlie these transitions. The analysis confirmed previously described processes or events, but more important, EASE revealed new insights. Response to DNA damage and DNA repair genes are overrepresented in the oocyte compared to 1-cell through blastocyst stages and may reflect the oocyte's response to selective pressures to insure genomic integrity; fertilization results in changes in the transcript profile in the 1-cell embryo that are far greater than previously recognized; and genome activation during 2-cell stage may not be as global and promiscuous as previously proposed, but rather far more selective, with genes involved in transcription and RNA processing being preferentially expressed. These results validate this hypothesis-generating approach by identifying genes involved in critical biological processes that can be the subject of a more traditional hypothesis-driven approach.

Molecular and ultrastuctural changes of rat pre-implantation embryos during two-cell developmental arrest

“…This was expected since cell cycle and protein degradation through ubiquitin-protesome pathways work coordinately to enable rapid production and degradation of proteins that lead to progression of cell cycle [30]. Similar biological processes were also up-regulated in mouse embryos where mRNAs encoding proteins involved in cell cycle and protein catabolism increased in 2-cell mouse embryos [31]. Contrary to our results, Zeng et al [31] reported significant increase in mRNSs involved RNA processing in 2-cell mouse embryos.…”

HDAC1 and HDAC2 in mouse oocytes and preimplantation embryos: Specificity versus compensation

“…85 Several lines of evidence support a role for HDAC1 in development of a transcriptionally repressive state that initiates in 2-cell embryos. 42 First, microarray data and qRT-PCR show that Hdac1 is zygotically expressed beginning from 2-cell stage, 42,86,87 accompanying genome activation. Second, HDAC1 protein enters into nucleus in late 2-cell embryos that is concomitant with zygotic genome activation at this stage ( Figure 2).…”

The PcG gene Sfmbt2 is paternally expressed in extraembryonic tissues

“…The shorter isoform, which is predicted to encode a truncated protein containing only one MBT domain, results from the use of a polyA site within exon 6. Expression of Sfmbt2 in preimplantation embryos is characteristic of a group of genes with a mid-preimplantation gene activation pattern, when major embryonic expression commences between the 8-cell and blastocyst stage (Fig1C), as assessed from published microarray data (Zeng et al, 2004;Hamatani et al, Dev Cell, 2004). Genes with this expression pattern have been purported to have roles in blastocyst formation and the emergence of distinct cell types in the preimplantaion embryo.…”

“…of expression for single androgenetic (n=34), gynogenetic (n=7), and biparental (n=24) blastocysts. Expression data of Sfmbt2 through preimplantation development were compiled from Zeng et al, 2004.…”