ABSTRACT
Ring1 and Yy1 binding protein (Rybp) has been implicated in transcriptional regulation, apoptotic signaling and as a member of the polycomb repressive complex 1, it has an important function in regulating pluripotency and differentiation of embryonic stem cells (ESCs). Earlier, we had proved that Rybp plays an essential role in mouse embryonic and central nervous system development. This work identifies Rybp, as a critical regulator of heart development. Rybp is readily detectable in the developing mouse heart from day 8.5 of embryonic development. Prominent Rybp expression persists during all embryonic stages, and Rybp marks differentiated cell types of the heart. By utilizing rybp null ESCs in an in vitro cardiac differentiation assay, we found that rybp null ESCs do not form rhythmically beating cardiomyocytes (CMCs). Gene expression profiles revealed a downregulation of cardiac terminal and upregulation of germline-specific markers in the rybp null CMCs. Furthermore, transcriptome analysis uncovered a number of novel candidate target genes regulated by Rybp. Among these are several that are important in cardiac development and contractility such as Plagl1, Isl1, and Tnnt2. Importantly, forced expression of rybp in rybp-deficient ESCs by a lentiviral vector was able to rescue the mutant phenotype. Our data provide evidence for a previously unrecognized function of Rybp in heart development and point out the importance of germ cell lineage gene silencing during somatic differentiation.
Subject(s)
Heart/embryology , Mouse Embryonic Stem Cells/cytology , Myocytes, Cardiac/cytology , Organogenesis/genetics , Repressor Proteins/genetics , Animals , Cell Cycle Proteins/genetics , Cell Differentiation/genetics , Cell Lineage/genetics , Cells, Cultured , Embryonic Development/genetics , Gene Expression Regulation, Developmental , Genes, Tumor Suppressor , LIM-Homeodomain Proteins/genetics , Mice , Myocardium/cytology , Polycomb Repressive Complex 1/metabolism , Transcription Factors/genetics , Troponin T/geneticsABSTRACT
We studied differential gene expression in ipsilateral and contralateral bovine oviduct epithelial cells using a combination of subtracted cDNA libraries and cDNA array hybridization. Four Simmental heifers were synchronized and slaughtered 3.5 days after they entered standing heat. Epithelial cells were isolated from ipsilateral and contralateral oviducts. To identify genes that are differentially regulated in ipsilateral and contralateral epithelium, subtracted cDNA libraries were produced by suppression subtractive hybridization and analyzed by cDNA array hybridization. Sequencing of cDNAs showing differential expression levels in ipsilateral and contralateral epithelium revealed 35 different cDNAs, 30 of which matched genes with known functions and 5 of which matched genes without a known function. The majority of genes (n = 27) were expressed at a higher level in the ipsilateral oviduct, but for some genes (n = 8), mRNA abundance was higher in the contralateral oviduct. The regulated genes or their products include a variety of functional classes such as cell-surface proteins, cell-cell interaction proteins, members of signal transduction pathways, immune-related proteins, and enzymes. Identification of genes differentially regulated in ipsilateral and contralateral oviduct epithelial cells is the first step toward a systematic analysis of local mechanisms that regulate the function of the bovine oviduct epithelium in the postovulation period.
