Human stem cells have been coaxed into forming heart progenitor cells that then develop into more-specialized heart cells.

Researchers have struggled to turn stem cells into large pools of cardiac cells that would further divide. Christine Mummery at Leiden University Medical Center in the Netherlands and her colleagues introduced into human stem cells a version of the MYC gene that they could control. By turning the gene on at key points during the cells' development, the researchers could keep the cells at a certain stage, and expand their number. With further regulation of certain biochemical signalling pathways, the team converted those cells into pacemaker or ventricular cells.

This approach could be used to create new models of human cardiac disease, the authors say.

Nature Biotechnol. http://dx.doi.org/10.1038/nbt.3271 (2015)