Rights: The University of Waikato Published 28 June 2011 Download

Cells decide what they will become in the embryo. Associate Professor Peter Dearden, from the University of Otago, is interested how our genes control this process.


Cells decide what they are going to be in the embryo. So if you think about an embryo, it starts with a single cell which is fertilised and then that cell goes on to divide to produce two cells, and four cells and eight cells, and eventually those cells have to start becoming different, because we have different cells in different parts of our bodies, so we’ve got to get a liver in the right place and a kidney in the right place.

And a lot of what we do is study how cells make those decisions, and we don’t know in most cases how cells make those decisions, but we are beginning to understand that almost all of development is controlled by genes – so all of the processes that happen in development, of marking out where cells are going to be forming to produce an organ or what sort of cells are going to be controlled by genes. So marking out where bits of the embryo are, that’s controlled by genes, and how cells turn into particular sorts of cells – into liver cells or kidney cells – that’s controlled by genes.

So genes are the major part of this process. It’s not to say the environment doesn’t have an effect, but the environment has an effect through changing how genes work. So it’s a genetic process that makes an embryo and makes the cell types in an embryo and the organs and tissues.

Victor French, University of New Mexico, Valencia Campus, Science Department.
The C. Everett Koop Institute, Dartmouth Medical School, Dartmouth-Hitchcock Medical Center, Dartmouth College