Proteins set clock for embryonic neural development, study suggests
A team of British and French geneticists has discovered how the interaction of two proteins controls the development of an embryo's brain and nervous system. The finding, published in PLoS Biology, also sheds light on the formation of other organ systems in the body and stem cell behaviour. The research team led by Professor Claudio Stern of the University College London (UCL) found that, in order for the nervous system not to develop prematurely in vertebrate embryos, there is a sequence of reactions that take place when the embryo is only a few hours old. These reactions temporarily stop the development of neural cells. More specifically, during gastrulation, when the three embryonic cell layers (ectoderm, mesoderm, and endoderm) are formed, a protein called ERNI prevents another protein - namely Geminin - from activating the Sox2 gene, which plays a crucial role in setting up the nervous system. It is only after gastrulation is completed that a new protein called BERT, discovered by the lead-author of the study, Dr Costis Papanayotou, binds with ERNI and Geminin, unblocking Sox2 and thus kick-starting the development of the brain and the neural system. 'Scientists have been looking for a long time for the switches that determine when cells in the embryo take on specific roles,' says Professor Stern, whose team initially discovered the ERNI protein. 'Our work shows that the proteins BERT and ERNI have an antagonistic relationship: BERT is stronger and overrides ERNI's suppression of the Sox2 gene.' The same gene is also crucial in helping stem cells to retain their ability to develop into all kinds of other cells and to renew themselves. This study could therefore make some contribution to the controversial area of stem cell research. The study received financial support from the EU Network of Excellence 'Cells into Organs', as well as the UK's Medical Research Council (MRC), the US National Institute of Mental Health and the French national league against cancer.
Countries
France, United Kingdom