Sweden : developing a comprehensive atlas of the early genetic development of the brain

Researchers at the Swedish Karolinska Institute have presented an atlas of early brain development that can be used to find out what went wrong in the development of brain tumors in children as well as to find new treatments.

The international research team mapped fetal brain development between the sixth and thirteenth weeks.

“This is the first comprehensive study of brain development with a focus on gene regulation,” said Sten Linarsson, professor of molecular systems biology at the Department of Medical Biochemistry at Karolinska Institutet. “It involved systematic mapping of the entire brain, so that all regions could be compared to each other.”

The development of the brain in the fetus begins in its early stages, resembling a tube, as the walls of the tube develop into the shape of a complete brain, and the center of the tube filled with fluids becomes the ventricles, that is, the brain cavity.

Between the sixth and thirteenth weeks of pregnancy, rapid specialization of the cells in the walls of the tube occurs through a very complex chain reaction, in which substances are secreted that stimulate the first cells to develop in a specific way. These cells then secrete additional signals that control the next stage of cell development, and so on.

The signals activate genes that produce specialized proteins in different cell types, and also act as new signals.

“We wanted to follow the process from DNA to RNA to protein at each step,” says Lennarsson.

The research team used a method that can measure active regions on DNA and RNA chains formed in individual cells, with the aim of providing a detailed map of the development process.

This research is part of the larger Swedish project “Atlas of Human Developmental Cells,” in which several research groups studied the genetic development of the brain, heart, and lungs.

Now, researchers are using the maps to decipher the evolutionary errors that lead to brain diseases.

“We are now studying the onset of brain cancer in children, as well as tumors that arise during the fetal stage,” Linarson explained.

The research was published in the journal Nature.