A recently fertilised embryo contains rapidly dividing cells that have the potential to develop into any part of the body. One of life's biggest mysteries is how cells in the early embryo decide what to be.
Cohesin proteins are essential for both chromosome duplication and for controlling expression of specific developmental genes. Therefore, we hypothesise that cohesin forms a vital link between cell division and differentiation. A global aim of our research is to discover novel cohesin-dependent mechanisms of cell fate choice.
When chromosomes replicate, they must be held together until the cell is ready to divide, ensuring each daughter cell gets the correct number of chromosomes during cell division. Cohesin is a protein complex that makes up the “glue” that holds chromosomes together from S phase until their separation at anaphase.
The Rad21 protein is a subunit of mitotic cohesin (which contains additional subunits Smc1, Smc3 and SA1/2). Exciting results from our work in the zebrafish animal model revealed an unanticipated role for Rad21 in regulating the expression of specific genes (Horsfield et al. 2007, Rhodes et al., 2010).
We believe that cohesin and other chromosome cohesion proteins can contribute to animal development and cancer through regulation of gene expression. For most of our research, our laboratory investigates regulatory pathways that operate downstream of these genes using a vertebrate model: the zebrafish.
Since there is high conservation of developmental genes throughout evolution, we will be able to use the information from our zebrafish model to interpret developmental roles cohesin might play in mammals and humans.
The zebrafish offers several advantages that make it an important tool for modelling human disease.
The optical clarity of zebrafish embryos and larvae, plus their external development, allows easy visualisation of developmental processes, an attribute not found in mammalian systems.
More information about zebrafish
For more information, please see the Otago Zebrafish Facility website: