Strong BERT quells ERNI

BERT and ERNI may be familiar to Sesame Street fans, but now researchers have found that play a vital role in embryonic development.

BERT and ENRI interact to control embryogenesis

UCL (University College London) scientists have discovered how two proteins called BERT and ERNI interact in embryos to control when different organ systems in the body start to form, deepening our understanding of the development of the brain and nervous system and stem cell behaviour.

Professor Claudio Stern, leader of the team, said: “Scientists have been looking for a long time for the switches that determine when cells in the embryo take on specific roles.”

The new research solves a part of the puzzle of how vertebrates prioritise the order in which they begin to develop different sets of structures. During development only a few signals instruct cells to form thousands of cell types, so the timing of how cells interpret these signals is critical. The international research team of the UCL Department of Anatomy & Developmental Biology has shown that the first stage of development of the brain and nervous system is, paradoxically, a block on its progression.

“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, which has a crucial function in setting up the nervous system,” said Professor Stern.

The scientists describe a sequence of reactions that take place when vertebrate embryos are only a few hours old that together act as a timing mechanism, temporarily stopping the development of neural cells - cells that go on to form the brain and nervous system. This gives a head-start to other cells in the embryo that will go on to create the body’s internal organs and skin and prevents the nervous system from developing prematurely.

The work was published in PLOS Biology.