Current Research Focus
- Identification of SOX3 Target GenesD. McAninch, E. Szarek
We have shown that SOX3 is a key regulator of neurogenesis in mice and humans. However, nothing is currently known about the genes/pathways that are regulated by this important transcription factor. The aim of this project is to identify genes that are regaulted by SOX3 in the developing mouse brain. This project will utilise two existing mouse models that lack SOX3 or overexpress SOX3. Using microarray and/or protemics technology, we will identify genes/proteins that are expressed at different levels in the neuroprogenitor cells of knock-out versus transgenic embryos. These putative target genes will be validated using RT-PCR and in-situ hybridisation analysis of wild-type, knock-out and transgenic Sox3 embryos. To identify direct SOX3 targets, Bioinformatics analysis of promoter sequences from the downstream genes will be used to identify SOX3 consensus binding sites. These will be assayed by Sox3 protein binding in vivo using chromatin immunoprecipitation (ChIP) assay.
- Determining the Impact of Altered SOX3 Dosage on Neurodevelopment Using Mouse ModelsK. Lee, N. Rogers
Adult brains from mice and humans with altered SOX3 dosage have distinct structural abnormalities that appear to arise from impaired differentiation of neural progenitor cells during embryonic development. This phenotype is consistent with the expression of Sox3, which is restricted to the progenitor cell population and is downregulted during differentiation into neurons and glia. However, at present, nothing is known about the mechanism by which neurogenesis is altered in response to abnormal levels of SOX3 in mice and humans.
The aim of this project is to determine the developmental and molecular impact of altered Sox3 dosage in the embryonic mouse brain through detailed comparison of wild-type, knock-out and transgenic Sox3 embryos. Several properties of neural progenitors will be investigated including proliferation, survival, specification, commitment and differentation. This project will employ many important molecular and cell biology techniques such as PCR, dual fluorescence immunohistochemistry, cloning, in vitro transcription and in situ hybridisation.
- Impact of mutant SOX3 protein on neurodevelopmentJ. Hughes
Polyalanine expansion mutations have recently been recognised as an important new class of mutations and have been identified in eight transcription factor genes that are associated with congenital syndromes in humans. Our functional analysis of wildtype and mutant SOX3 proteins in cell lines and chick embryos indicate that mutant proteins misfold and generate cytoplasmic and nuclear aggregates with poor transcriptional activity.
To determine the impact of mutant SOX3 protein on neurodevelopment, we are using targeted mutagenesis to generate Embryonic Stem Cells and mice that contain a Sox3 polyalanine expansion allele. Comprehensive in vitro and in vivo analyses of neuro-differentiation in these mutant ES cells and mice will provide key insights into the functional consequences of Sox3 polyalanine expansions and the molecular pathology of patients with XH.
- Function and redundancy of SOX genes in the mammalian sex determination pathwayE. Sutton
We are studying a mouse model of abnormal sex organ development in which genetically female mice develop as males. Our basic research program will lead to greater understanding of the genetic switch controlling the formation of male and female characteristics. This research should in turn provide insight into the causes of defects in patients with disorders of sex development, helping to inform the difficult clinical decisions that need to be made for their treatment, and ultimately leading to better management and therapeutic strategies. Our studies may also provide unique methods to control the exotic mouse population, using the daughterless strategy.
Dr. Robin Lovell-Badge
Division of Developmental Genetics
National Institute for Medical Research