Scientists Successfully Grow Model of an Embryo

( – Scientists have developed a near-human embryo without using an egg, sperm, or a womb. Researchers at the Weizmann Institute of Science in Israel created a model of a human embryo using stem cells, following experiments during which they successfully created a mouse fetus with the same technology. The human-like embryo even emitted enough hormones to produce a positive result on a pregnancy test.

The purpose of the research is not to create humans, but to study what takes place in early pregnancy, something not possible on an actual fetus for obvious ethical reasons.

The scientists said the artificial embryo had all the characteristics of a real one. This included a placenta and membranes, and other elements that would be expected for a human at this stage of development. Research team leader Professor Jacob Hanna said, “It closely mimics the development of a real human embryo, particularly the emergence of its exquisitely fine architecture.”

In place of an egg and sperm, the scientists started with  naïve stem cells, which can be coaxed into developing into a range of different cells. These became epiblast cells – which developed into the embryo, trophoblast cells – which evolved into the placenta, hypoblast cells, and extraembryonic mesoderm cells – which became the embryo’s support system. Scientists placed a total of 120 mixed cells in a dish with naïve stem cells and waited to see what life produced.

Life spontaneously produced an embryo in what is a historic biological first.

Some scientists, however, say the samples are far from perfect – perhaps allaying certain ethical concerns. Some believe that the artificial embryos cannot develop further.

Dr. Peter Rugg-Gunn, from the Babraham Institute near Cambridge in England, described the work as “impressive” and “significant” but said not all features of a human embryo were present, while others are not organized correctly. “This embryo model would not be able to develop if transferred into a womb,” he concluded.

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