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. Overall design: Examination of transcription of Mouse PGCs
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:We have developed a tet-inducible immortalized mouse embryonic fibroblast (iMEF) cell culture model of SDH-loss paraganglioma/pheochromocytoma in which silencing gene rearrangement of the Sdhc floxed allele is driven by doxycycline-dependent expression of cre-recombinase from a tet-inducible promoter (R26M2rtTA/+;TetOcre;Sdhcfl/fl). Using this model and an isogenic Sdhc wt control line (R26M2rtTA/+;TetOcre;Sdhcfl/wt), we have characterized the time-course of Sdhc gene rearrangement, protein loss, and succinate accumulation following induction with doxycycline. Using reduced representation bisulfite sequencing (RRBS), we have quantified changes in the genome-wide distribution of cytosine/5’-methyl-cytosine due to succinate accumulation using our Sdhc -/- cell line. Through a time-course experimental design, we have grown R26M2rtTA/+;TetOcre;Sdhcfl/fl (experimental) and R26M2rtTA/+;TetOcre;Sdhcfl/wt (control) iMEFs in standard DMEM media containing 10% FBS and quantified DNA methylation changes in these cells as a function of time after triggering SDHC gene rearrangement via doxycycline exposure. Overall design: Included in this dataset are single replicate RRBS time course data for experimental (R26M2rtTA/+;TetOcre;Sdhcfl/fl) and control (R26M2rtTA/+;TetOcre;Sdhcfl/wt) cell lines at days 0, 5, 9, 12,16, and 20 after induction with doxycycline.