- Date de publication : 2009-02-03
Vigneault C, Gravel C, Vallée M, McGraw S, Sirard MA. Unveiling the bovine embryo transcriptome during the maternal-to-embryonic transition. Reproduction. 2009;137:245-57. doi: 10.1530/REP-08-0079. PubMed PMID: 18987256.
animals cattle dna primers embryonic development female gene expression profiling gene expression regulation, developmental in situ hybridization oligonucleotide array sequence analysis pregnancy reverse transcriptase polymerase chain reaction transcription, genetic
Bovine early embryos are transcriptionally inactive and subsist through the initial developmental stages by the consumption of the maternal supplies provided by the oocyte until its own genome activation. In bovine, the activation of transcription occurs during the 8- to 16-cell stages and is associated with a phase called the maternal-to-embryonic transition (MET) where maternal mRNA are replaced by embryonic ones. Although the importance of the MET is well accepted, since its inhibition blocks embryonic development, very little is known about the transcripts expressed at this crucial step in embryogenesis. In this study, we generated and characterized a cDNA library enriched in embryonic transcripts expressed at the MET in bovine. Suppression subtractive hybridization followed by microarray hybridization was used to isolate more than 300 different transcripts overexpressed in untreated late eight-cell embryos compared with those treated with the transcriptional inhibitor, alpha-amanitin. Validation by quantitative RT-PCR of 15 genes from this library revealed that they had remarkable consistency with the microarray data. The transcripts isolated in this cDNA library have an interesting composition in terms of molecular functions; the majority is involved in gene transcription, RNA processing, or protein biosynthesis, and some are potentially involved in the maintenance of pluripotency observed in embryos. This collection of genes associated with the MET is a novel and potent tool that will be helpful in the understanding of particular events such as the reprogramming of somatic cells by nuclear transfer or for the improvement of embryonic culture conditions.