Scientists have developed an entity that closely resembles one early human embryowithout using sperm, eggs or uterus.

According to a BBC report, the Weizmann Institute team announced that their “embryo model”, developed using stem cells, resembles a real 14-day-old embryo.

According to the scientists involved in the effort, the purpose of creating embryo models is to provide an ethical way of understanding the first moments of our lives.

The first few weeks after an egg is fertilized by sperm is a time of dramatic change – from a collection of indistinct cells to what eventually begins to take the form of an embryo

During this critical period, several miscarriages are recorded and genetic anomalies appear, without the scientific community having enough knowledge about these cases.

“It’s a ‘black box’ and that’s not a cliché – our knowledge is very limited,” Professor Jacob Hanna, from the Weizmann Institute of Science, told the BBC.

Research on embryos is legally, ethically and technically limited. But now there is a rapidly growing field that mimics and models natural fetal development. This research, published in the journal Nature, is described by the Israeli team as the first “complete” embryo model, mimicking all the basic structures that appear in the early embryo.

“It’s really a textbook image of a day 14 human embryo,” says Professor Hanna, which “has never been done before.”

Instead of sperm and egg, the starting material was primitive stem cells reprogrammed to become any type of tissue in the body.

Chemicals were then used to turn these stem cells into four types of cells found in the early stages of the human embryo:

  • epiblast cells, which become the actual embryo
  • trophoblast cells, which become the placenta
  • hypoblastic cells, which become the amniotic sac
  • cells of extraembryonic mesoderm