'Flip-flop' Switch Behind Cellular Process

Scientists from the John Innes Centre reported in the journal Cell that they have discovered a molecular switch that signals asymmetric cell divisions in a stem cell and ensures that these occur at the right location and time, to produce layers of specialized root tissues.

"Through an experimental-modelling cycle, we have unravelled how stem cells in the Arabidopsis root regulate asymmetric cell divisions that give rise to two new cell identities at the correct position," said Dr Stan Marée of the John Innes Centre. "We dissected the underlying molecular circuit which operates in each cell, and found that it presented a highly robust bistable behaviour, due to two positive feedback loops involving the proteins SHR, SCR and the cell-cycle related players RBR and CYCLD6;1. In other words, we showed that the circuit behaves like a (flip-flop) switch."

With this discovery, it is possible that similar molecular circuitry could be also involved in other important cellular processes.

Read the original article at http://news.jic.ac.uk/2012/08/flip-flop-switch/ and the research article at http://www.sciencedirect.com/science/article/pii/S009286741200880X.