Working out the functions of individual genes in human cells is now much simpler thanks to a new database of time-lapse movies showing cells in action.
Jan Ellenberg of the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, and his colleagues across Europe introduced the freely accessible database of 190,000 videos to the scientific community along with a paper published today in Nature1.
Ellenberg and his team set out to observe what happens to cells when each of the 21,000 human protein-coding genes is disrupted. They perturbed gene expression using short interfering RNA molecules (siRNA) and then observed the effects over two days on fluorescently labelled chromosomes using time-lapse imaging. Because this generated huge amounts of data — more than 19 million cell divisions — the researchers developed computational tools to analyse all of the videos. Their technique automatically tracked the position of the nucleus in each cell and classified its appearance into 16 different categories. The method recognized with 87% accuracy changes in the nuclear shape that were related to basic functions such as cell division, proliferation, survival and migration.
“Technically this paper is really a tour de force,” says Jason Swedlow, a cell biologist at the University of Dundee, UK. “The systematic way the group has gone through and knocked down genes and filmed the results is really impressive.”