Project description:Neural differentiation of embryonic stem cells (ESCs) requires coordinated repression of the pluripotency regulatory programme and reciprocal activation of the neurogenic regulatory programme. Upon neural induction, ESCs rapidly repress expression of pluripotency genes followed by staged activation of neural progenitor and differentiated neuronal and glial genes. The transcriptional factors that underlie pluripotency are partially characterized, whereas those underlying neural induction are much less explored, and the factors that coordinate these two developmental programs are completely unknown. One transcription factor, REST (RE1 silencing transcription factor), has been linked with terminal differentiation of neural progenitors, and more recently and controversially, with control of pluripotency. Here, we show that in the absence of REST, coordination of pluripotency and neural induction is lost and there is a resultant delay in repression of pluripotency genes and a precocious activation of both neural progenitor and differentiated neuronal and glial genes. Further, we show that REST is not required for production of radial glia-like progenitors but is required for their subsequent maintenance and differentiation into neurons, oligodendrocytes and astrocytes. We propose that REST acts as a regulatory hub that coordinates timely repression of pluripotency with neural induction and neural differentiation. We have investigated the role of REST in the coupling of pluripotency and neural induction and neurogenesis using Rest-null mouse ESCs (mESCs) in conjunction with a novel mESC neural differentiation protocol. Differential expression between Rest-null ESCs and controls was tested using Illumina Mouse Ref-8 v2 BeadArray technology. Three replicates were used for Rest-null and three for control. Data analysis was performed using Bioconductor libraries beadarray and limma.
Project description:Neural differentiation of embryonic stem cells (ESCs) requires coordinated repression of the pluripotency regulatory programme and reciprocal activation of the neurogenic regulatory programme. Upon neural induction, ESCs rapidly repress expression of pluripotency genes followed by staged activation of neural progenitor and differentiated neuronal and glial genes. The transcriptional factors that underlie pluripotency are partially characterized, whereas those underlying neural induction are much less explored, and the factors that coordinate these two developmental programs are completely unknown. One transcription factor, REST (RE1 silencing transcription factor), has been linked with terminal differentiation of neural progenitors, and more recently and controversially, with control of pluripotency. Here, we show that in the absence of REST, coordination of pluripotency and neural induction is lost and there is a resultant delay in repression of pluripotency genes and a precocious activation of both neural progenitor and differentiated neuronal and glial genes. Further, we show that REST is not required for production of radial glia-like progenitors but is required for their subsequent maintenance and differentiation into neurons, oligodendrocytes and astrocytes. We propose that REST acts as a regulatory hub that coordinates timely repression of pluripotency with neural induction and neural differentiation.
Project description:Neural crest cells are migratory progenitor cells that contribute to nearly all tissues and organs throughout the body. Their formation, migration and differentiation are regulated by a multitude of signaling pathways, that when disrupted can lead to disorders termed neurocristopathies. While work in avian and amphibian species has revealed essential factors governing the specification and induction of neural crest cells during gastrulation and neurulation in non-mammalian species, their functions do not appear to be conserved in mice, leaving major gaps in our understanding of neural crest cell formation in mammals. Here we describe Germ Cell Nuclear Factor (GCNF/Nr6a1), an orphan nuclear receptor, as a critical regulator of neural crest cell formation in mice. Gcnf null mutant mice, exhibit a major disruption of neural crest cell formation. The purpose of this experiment is to examine gene expression changes in response to Gcnf mutation in E9.0 mouse embryos.
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.
Project description:Neural crest cells are migratory progenitor cells that contribute to nearly all tissues and organs throughout the body. Their formation, migration and differentiation are regulated by a multitude of signaling pathways, that when disrupted can lead to disorders termed neurocristopathies. While work in avian and amphibian species has revealed essential factors governing the specification and induction of neural crest cells during gastrulation and neurulation in non-mammalian species, their functions do not appear to be conserved in mice, leaving major gaps in our understanding of neural crest cell formation in mammals. Here we describe Germ Cell Nuclear Factor (GCNF/Nr6a1), an orphan nuclear receptor, as a critical regulator of neural crest cell formation in mice. Gcnf null mutant mice, exhibit a major disruption of neural crest cell formation. The purpose of this experiment is to examine gene expression changes in response to Gcnf mutation in anterior and posterior cranial regions of E9.25 mouse embryos.