Scientists have developed a human embryo ‘blueprint’ from human stem cells, in a breakthrough that could give a vital insight into the early stages of infant development.

The model made by the teams from the University of Cambridge and the Netherlands-based Hubretcht Institute said the embryo will allow them to observe ‘never-before-seen-process’ underlying human body’s formation.

Human layout – known as the body plan – occurs through a process known as gastrulation, in which three distinct layers of cells are formed in the embryo, which will later give rise to the three main systems of the body: nervous, musculoskeletal, and digestive.

Gastrulation is known as human development’s “black box” period, as legal constraints prevent scientists from developing embryos in the laboratory after 14 days. The team behind the study said their model resembles an embryo between the age of 18 and 21, around the same time as gastrulation is taking place.

During this period, many birth defects occur, and a better understanding of gastrulation could help us understand issues such as infertility, miscarriage, and genetic disorders, the researchers said.

The lead author Alfonso Martinez-Arias from Cambridge’s Department of Genetics said,

“Our model produces part of the blueprint of a human. It’s exciting to witness the developmental processes that until now have been hidden from view  and from the study.”

The team collected tight bundles of human cells to create the three-dimensional models known as gastruloids, and treated them with chemicals that served as signals to activate certain genes.