Researchers have developed a human embryo “drawing” with the help of human stem cells, in a breakthrough that can provide important insight into the early stages of infant development, new research showed Thursday.
Teams from the University of Cambridge and the Netherlands-based Hubrecht Institute said their model will allow them to observe processes that have not previously seen the underlying formation of the human body.
The human layout – known as the body plan – takes place through a process called gastrulation, where three distinct cell layers are formed in the embryo that will later give rise to the body’s three main systems: nerve, musculoskeletal and digestive tract.
Gastrulation is known as the “black box” period for human development because legal restrictions prevent researchers from developing embryos in the lab after 14 days.
The team behind the study, published in Nature, said their model is similar to an embryo between 18 and 21 days old, roughly at the same time as gastrulation occurs.
Many birth defects occur during this period, and a better understanding of gastrulation can help our understanding of issues such as infertility, miscarriage and genetic disorders, the researchers said.
“Our model produces part of a human’s plan,” said lead author Alfonso Martinez-Arias, of Cambridge’s genetic department.
“It is exciting to see the development processes that have so far been hidden from view – and from the study.”
To create the three-dimensional models, so-called gastruloids, the team collected narrow bundles of human cells and treated them with chemicals that acted as signals to activate certain genes.
This is the first time, say the researchers, that human stem cells have been used to create a 3D human embryo after some experiments with stem cells from mice and zebrafish.
The researchers emphasized that gastruloids never develop into fully formed embryos because they have no brain cells and lack any tissue for implantation in the uterus.
Still, they were able to observe about 72 hours after the model’s development and identify clear signs of events that led to the formation of muscles, bones and cartilage.
Jeremy Green, professor of developmental biology at King’s College London, said the study was a “fantastic window” into the early formation of the human body.
“(It) highlights the amazing power of self-organization of cells and tissues with the right conditions,” added Green, who was not involved in the research.
© Agence France Press