Embryology Unit Children's Medical Research Institute

Lab head: Professor Patrick Tam
Location: Children's Medical Research Institute

This project explores the cellular and molecular mechanism of the establishment of the body plan and the formation of organs during embryonic development and elucidates how faults in the morphogenetic process disrupts development using genetic models of birth defects and embryo-derived stem cells.

Website: http://www.cmri.org.au/Research/Research-Units/Embryology
Lab members: Dr Nicolas Fossat
Funding: NHMRC
Research approach equipment: Genome analysis (RNA-seq, ChIP-Seq, iCLIP-Seq, ChIP-nexus, microfluidic qPCR and single-cell transcriptome), protein analysis (mass-spectrometry, BioID, yeast two-hybrid), bioinformatics, system biology, genome editing (CRISPR-Cas9, Piggy-Bac transposase, Cre-loxP system), dissection and manipulation of mouse embryos, molecular biological methods for gene cloning and analysis of gene expression (including real-time PCR and in situ hybridization), histology, immunofluorescence, cell culture, generation of organoids, transfection, organoids, cell and embryo electroporation.

Control of cell differentiation during mouse embryogenesis and stem cell development

Primary supervisor: Patrick Tam

The knowledge of how to maintain, expand and differentiate stem cells is essential for the realisation of clinical cell-based therapy for the replacement and repair of diseased tissues.  Cells of the early embryo are capable of generating many cell types, hence are regarded as pluripotent cells.  As the embryo develops, there is a progressive restriction of the ability of the cells to do so.  Cells in more advanced embryos will give rise to an increasingly limited set of cell types.  We are documenting the genome-wide transcriptome (expression profiles) of the cell population at all definable positions in the embryo, which will enable the tracking of the essential activity of the gene regulatory network and signalling pathways driving cell fate choices and lineage progression during gastrulation.  The network and pathway function will be verified by tracking lineage differentiation in genetically modified embryos.

Recently, stem cells have been derived from mouse embryos at the post-implantation stage.  These epiblast stem cells differ from the conventional embryonic stem cells, regarding the culture conditions for maintenance and differentiation, suggesting that they are a different type of stem cell that are already predisposed for more specialized differentiation.  This project will examine if these stem cells may be induced to differentiate more efficiently into specific types of embryonic tissue by recapitulating the genetic and signalling  activity that regulate cell differentiation in the embryo. Specifically, we will focus on one transcription factor, Mixl1, a cell-fate specifier expressed uniquely at this stage of development. We will study upstream signalling pathways (WNT,TGFb) that are controlling the expression of Mixl1 as well as its downstream targets. To this aim, stem cells will be differentiated by using cutting edge experimental tools such as gastruloid production and micro-patterning of cell populations that recapitulate the early embryo development. Transcriptome analysis of the cell population complemented with single cell analysis will be conducted to glean a comprehensive view of the molecular mechanisms of cell fate decision, which will inform us on how to generate by design of cell types with unique attributes for therapeutic application by design from other pluripotent stem cells.

Discipline: Applied Medical Sciences, Westmead
Keywords: Genetics, Molecular biology, Stem cells