PAPERS TO WATCH

Robert Singer and colleagues at the Albert Einstein College of Medicine in New York recently visualized individual Dictyostelium discoideum cells transcribing dscA, a gene that increases in expression during development. Using an in vivo system that tags nacent mRNA, they showed dscA is transcribed in pulses. ¹ Rather than a steady, wholesale increase in transcription, Singer?s group showed the intensity and duration of dscA transcription pulses remain the same. Surprisingly, it?s the number of expressing cells that increases. Roger Patient, Faculty of 1000 member and professor at the University of Oxford, says this paper "forces you to think about transcription in a completely different way."

"People carry around a picture about these things. Most people would expect that once a gene is on, it?s on. And if it?s off, it?s off. It wouldn?t be flipping between the two all the time. But that?s what they found. They speculate that the reason for this on-off-on-off all the time is that switching it off is easier this way. Maybe it?s easier to disrupt transcription if it?s not locked in the on position."