Science News Review

BERT and ERNI Play Important Roles in CNS Development

Jan 10 at 10:10pm by Aileen

…and you thought those silly Muppets were just silly!

With the melodic strains of Ernie’s Greatest Hit “Rubber Ducky” echoing my head, fans will be delighted to know that the dynamic duo created by Jim Henson and Frank Oz in 1969 as stars of the famous Sesame Street educational program have even more to do with brain development that originally thought!

Research published in the January 10 online issue of PLoS Biology reports A Mechanism Regulating the Onset of Sox2 Expression in the Embryonic Neural Plate has been discovered.

The neural plate is a region of the ectoderm cells in early embryo development that gives rise to the entire central nervous system in vertebrate embryos. The earliest molecular marker that cells in this plate are beginning to differentiate into their respective neural types is the transcription factor known as Sox2. The researchers, from University College London, the Université de Lyon and CNRS/INRA in France and the Wellcome/Cancer Research UK Gurdon Institute for Cancer and Developmental Biology in Cambridge, found specific protein interactions that regulate the expression of N2, the earliest enhancer of Sox2. N2 directs Sox2 expression to the largest part of the neural plate.

The three coiled-coil domain proteins are ERNI, Geminin and BERT. Both BERT and ERNI also control when different organ systems in the developing embryo begin to form. Because just a few signals instruct cells to form the thousands of different cell types, timing is everything. The researchers describe a sequence of reactions that take place when the embryo is just a few hours old, which together act as a timing mechanism for developmental expression. The development of neural cells is repressed for a time so that other cells in the embryo that will develop into internal organs and skin get a head start on the central nervous system. To make this happen BERT binds to ERNI and other proteins that unblog the expression of Sox2 at just the right time to begin development of the brain and nervous system.

The discoveries and new understanding of how this signaling works in very early embryo development will have significant implications for stem cell research, which hopes to discover the biochemical signals that tell a stem cell what to become. One of these days - I’m hoping in my children’s generation - it may be possible for people with heart, kidney, liver or lung disease, spinal cord or brain injuries to “grow their own” new organs and neural cells from stem cells.

Links:

A Mechanism Regulating the Onset of Sox2 Expression in the Embryonic Neural Plate

Two Proteins, Called BERT and ERNI, Control Brain Development