An international team of scientists led by the University of Edinburgh has mapped the network of genomic switches responsible for regulating the expression of individual genes.

In a three-year project dubbed “FANTOM5,” researchers studied the world’s largest assemblage of cell types and tissues from the mouse and human to determine how those switches interact with one another to guide the physical phenomenon that is the living biological creature. More than 250 scientists from some 20 countries of the world participated in the project, with help from the RIKEN Center for Life Science Technologies in Japan.

Study leader David Hume, director of the Roslin Institute, described the work as a tremendous achievement in human self-understanding. “To use the analogy of an aeroplane, we have made a leap in understanding the function of all of the parts,” he said in a statement. “And now we have gone well beyond that, to understanding how they are connected and control the structures that enable flight.”

Published in the journal Nature on Wednesday, the study represents a new understanding of our human genome, which tells the body how to build cells and which genes to express. The genetic regulatory process is controlled by switches — referred to as promoters and enhancers — that mark the difference between one type of cell and another.

"The FANTOM5 project has identified new elements in the genome that are the targets of functional genetic variations in human populations, and also have obvious applications to other species,” Hume said.

As the research team publishes a series of academic papers from the study, the new evidence may help explain how humans differ from other species sharing much of our genome, including the 96 percent commonality between humans and chimpanzees, according to Martin Taylor of Edinburgh. "The research gives us an insight as to why humans are different from other animals, even though we share many genes in common," he said in the statement. “Comparing the mouse and human atlases reveals extensive rewiring of gene switches that has occurred over time, helping us to understand more about how we have evolved."

Already, researchers at Edinburgh are conducting separate studies using the new atlas to study the regulation of genes for building muscle and bone, as well as for the regulation of the immune system.

Source: Hume D, et al. Nature. 2014.