All starting from the same DNA, neurons ultimately take on individual characteristics in the brain and body. Differences in which genes they transcribe into RNA help determine which type of neuron they become, and from there, a new MIT study shows, individual cells edit a selection of sites in those RNA transcripts, each at their own widely varying rates.
The new study surveyed the whole landscape of RNA editing in more than 200 individual cells commonly used as models of fundamental neural biology: tonic and phasic motor neurons of the fruit fly. One of the main findings is that most sites were edited at rates between the “all-or-nothing” extremes many scientists have assumed based on more limited studies in mammals, says senior author Troy Littleton, the Menicon Professor in the MIT departments of Biology and Brain and Cognitive Sciences. The resulting dataset and open-access analyses, recently published in eLife, set the table for discoveries about how RNA editing affects neural function and what enzymes implement those edits.
“We have this ‘alphabet’ now for RNA editing in these neurons,” Littleton says. “We know which genes are edited in these neurons, so we can go in and begin to ask questions as to what is that editing doing to the neuron at the most interesting targets.”
