Much of what we know about biology comes from animal models, particularly mice. Applying these insights to humans, however, is not always straightforward. For example, some of the genes important for the formation of germ cells, which eventually give rise to eggs or sperm, differ between mice and humans.

To identify gene correspondences across species, researchers often compare DNA sequences. This helps establish evolutionary relationships between genes, but it does not always answer a more functional question: Which genes play similar regulatory roles within specific cell types or cell fate specification processes across species?

To explore this question, a team of researchers at Kyoto University’s Institute for the Advanced Study of Human Biology (WPI-ASHBi) looked at how genes are expressed in relation to one another. They reasoned that the overall organization of regulatory networks might remain similar across species, even when the genes involved differ.