ABSTRACT
The transition from a differentiated germ cell into a totipotent zygote during oogenesis and preimplantation development is critical to the creation of a new organism. During this period, cell characteristics change dynamically, suggesting that a global alteration of gene expression patterns occurs, which is regulated by global changes in various epigenetic factors. Among these, transcription factors (TFs) are essential in the direct regulation of transcription and also play important roles in determining cell characteristics. However, no comprehensive analysis of TFs from germ cells to embryos had been undertaken. We used mRNA amplification systems and microarrays to conduct a genomewide analysis of TFs at various stages of oogenesis and preimplantation development. The greatest alteration in TFs occurred between the 1- and 2-cell stages, at which time zygotic genome activation (ZGA) occurs. Our analysis of TFs classified by structure and function revealed several specific patterns of change. Basic transcription factors, which are the general components of transcription, increased transiently at the 2-cell stage, while homeodomain (HD) TFs were expressed specifically in the oocyte. TFs containing the Rel homology region (RHR) and Ets domains were expressed at a high level in 2-cell and blastocyst embryos. Thus, the global TF dynamics that occur during oogenesis and preimplantation development seem to regulate the transition from germ-cell-type to embryo-type gene expression.
Subject(s)
Embryo Implantation/genetics , Embryonic Development/physiology , Gene Expression Profiling , Gene Expression Regulation, Developmental/physiology , Oogenesis/physiology , Transcription Factors/physiology , Animals , Blastocyst/metabolism , Female , Homeodomain Proteins/metabolism , Mice , Oligonucleotide Array Sequence Analysis , Oocytes/physiology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transcription, GeneticABSTRACT
Previous studies have indicated that Ess1/Pin1, a gene in the parvulin family of peptidyl-prolyl isomerases (PPIases), plays an important role in regulating the G(2)/M transition of the cell cycle by binding cell-cycle-regulating proteins in eukaryotic cells. Although the ess1 gene has been considered to be essential in yeast, we have isolated viable ess1 deletion mutants and demonstrated, via analysis of yeast gene expression profiles using microarray techniques, a novel regulatory role for ESS1 in the G(1) phase. Although the overall expression profiles in the tested strains (C110-1, W303, S288c, and RAY-3AD) were similar, marked changes were detected for a number of genes involved in the molecular action of ESS1. Among these, the expression levels of a cyclophilin A gene, also a member of the PPIase family, increased in the ess1 null mutant derived from C110-1. Subsequent treatment with cyclosporin A significantly retarded growth, which suggests that ESS1 and cyclophilin A are functionally linked in yeast cells and play important roles at the G(1) phase of the cell cycle.
