Project description:To measure on a global scale the SV40 large T antigen-mediated changes in gene transcription in mouse embryo fibroblasts differing in the expression of p53. Samples of total RNA from 3T3 (wt p53) and 10-1 (p53-null) mouse embryo fibroblasts stably transfected with SV40 large T-antigen expressing pMYcLT vector (3T3 LT and 10-1 LT cells) or empty pMYsIG vector (3T3 IG and 10-1 IG cells) were subjected to gene expression analysis.
Project description:To measure on a global scale the SV40 large T antigen-mediated changes in gene transcription in mouse embryo fibroblasts differing in the expression of p53.
Project description:SV40 transforms cells through the action of two oncoproteins, large T antigen and small t antigen. Small t antigen targets phosphatase PP2A, while large T antigen stimulates cell proliferation and survival by action on multiple proteins, including the tumor suppressors Rb and p53. Large T antigen also binds components of the transcription initiation complex and several transcription factors. We examined global gene expression in SV40-transformed mouse embryo fibroblasts, and in enterocytes obtained from transgenic mice. SV40 transformation alters the expression of approximately 800 cellular genes in both systems. Much of this regulation is observed in both MEFs and enterocytes and is consistent with T antigen action on the Rb-E2F pathway. However, the regulation of many genes is cell-type specific, suggesting that unique signaling pathways are activated in different cell types upon transformation, and that the consequences of SV40 transformation depends on the type of cell targeted.
Project description:SV40 transforms cells through the action of two oncoproteins, large T antigen and small t antigen. Small t antigen targets phosphatase PP2A, while large T antigen stimulates cell proliferation and survival by action on multiple proteins, including the tumor suppressors Rb and p53. Large T antigen also binds components of the transcription initiation complex and several transcription factors. We examined global gene expression in SV40-transformed mouse embryo fibroblasts, and in enterocytes obtained from transgenic mice. SV40 transformation alters the expression of approximately 800 cellular genes in both systems. Much of this regulation is observed in both MEFs and enterocytes and is consistent with T antigen action on the Rb-E2F pathway. However, the regulation of many genes is cell-type specific, suggesting that unique signaling pathways are activated in different cell types upon transformation, and that the consequences of SV40 transformation depends on the type of cell targeted. Keywords: comparative genomic hybridization
Project description:Nucleolus-associated DNA was isolated from MEF cells before and after conditional knock-out of UBF and hybridized against genomic DNA in biological replicates. Two different types of immortalized MEF cells were used. MEFs were immortalized by genetic depletion of p53, iMEFs were immortalized by transfection of the SV40 Tt antigen.
Project description:PGCs undergo two distinct stages of demethylation before reaching a hypomethylated ground state at E13.5. Stage 1 occurs between E7.25- E9.5 in which PGCs experience a global loss of cytosine methylation. However, discreet loci escape this global loss of methylation and between E10.5-E13.5, stage 2 of demethylation takes place. In this stage these loci are targeted by Tet1 and Tet2 leading to the loss of the remaining methylation and resulting in the epigenetic ground state. Our data shows that Dnmt1 is responsible for maintaining the methylation of loci that escape stage 1 demethylation, and that it functions in a UHRF1 independent manner. Our data further demonstrates that when these loci lose methylation prior to stage 2 it results in early activation of the meiotic program, which leads to precocious differentiation of the germ line resulting in a decreased pool of PGCs in the embryo and subsequent infertility in adult mice.
