Splicing together a lineage from snapshots

Determining a temporal order of cellular events and developmental lineages on the basis of snapshots of single-cell RNA profiles is one of the great hurdles of single-cell approaches. Peter Kharchenko and colleagues propose to resolve this issue by analysing the ratio of unspliced versus spliced RNA to determine the time derivative of gene expression state and temporally order cells. They validate the methods on various published datasets and use it to determine branching decisions in the mouse hippocampus and analyse RNA changes in human embryonic brain.