Conserved molecular portraits of bovine and human blastocysts as a consequence of the transition from maternal to embryonic control of gene expression

James Adjaye, Ralf Herwig, Thore C. Brink, Doris Herrmann, Boris Greber, Smita Sudheer, Detlef Groth, Joseph W. Carnwath, Hans Lehrach, Heiner Niemann
2007 Physiological Genomics  
The present study investigated mRNA expression profiles of bovine oocytes and blastocysts by using a cross-species hybridization approach employing an array consisting of 15,529 human cDNAs as probe, thus enabling the identification of conserved genes during human and bovine preimplantation development. Our analysis revealed 419 genes that were expressed in both oocytes and blastocysts. The expression of 1,324 genes was detected exclusively in the blastocyst, in contrast to 164 in the oocyte
more » ... luding a significant number of novel genes. Genes indicative for transcriptional and translational control (ELAVL4, TACC3) were overexpressed in the oocyte, whereas cellular trafficking (SLC2A14, SLC1A3), proteasome (PSMA1, PSMB3), cell cycle (BUB3, CCNE1, GSPT1), and protein modification and turnover (TNK1, UBE3A) genes were found to be overexpressed in blastocysts. Transcripts implicated in chromatin remodeling were found in both oocytes (NASP, SMARCA2) and blastocysts (H2AFY, HDAC7A) . The trophectodermal markers PSG2 and KRT18 were enriched 5-and 50-fold in the blastocyst. Pathway analysis revealed differential expression of genes involved in 107 distinct signaling and metabolic pathways. For example, phosphatidylinositol signaling and gluconeogenesis were prominent pathways identified in the blastocyst. Expression patterns in bovine and human blastocysts were to a large extent identical. This analysis compared the transcriptomes of bovine oocytes and blastocysts and provides a solid foundation for future studies on the first major differentiation events in blastocysts and identification of a set of markers indicative for regular mammalian development. oocytes; microarrays; cross-species hybridization CRITICAL STEPS during early development such as the timing of first cell division, activation of the embryonic genome, compaction, blastocyst formation, expansion, and hatching are regulated by a well-orchestrated expression of genes. During the transition from maternal to embryonic control of development, maternal transcripts (common to both the unfertilized oocyte and the preimplantation embryo) are Address for reprint requests and other correspondence: J. Adjaye, Max
doi:10.1152/physiolgenomics.00041.2007 pmid:17595343 fatcat:4anll42fhbgiffr3ywddnlgkee