In a recent research work published in the journal Cell, a team led by researchers from the Weizmann Institute of Science in Israel have grown mouse embryo models using only stem cells outside the uterus in a special incubator. The embryo was developed without fertilising gametes, sperm and egg ,and without any assistance from the parents. The embryo shows evidence of a brain and a beating heart.

The development of an artificial mouse embryo outside a mother’s womb without the need for sperm or eggs is a major step forward in synthetic biology. The tiny embryo was constructed purely from stem cells, opening up intriguing but ethically problematic prospects for the future possibility of growing a live animal, including humans, solely from cultivated stem cells in a laboratory.

This is an excellent example of biotechnology that will aid researchers in understanding how stem cells function and whether or not they hold the key to curing a wide range of illnesses. According to the convention, Lifebegan when an egg met a sperm. One of the biggest mysteries in biology is how a little clump of cells can develop into a sophisticated biological system with many different types of specialised tissues and organs. Biologists have been dissecting embryos almost cell by cell for the past few decades to learn every nuance of their development.

Through careful study, scientists have gained a deeper understanding of the molecular messages and physical factors that mould embryos and the tissues that sustain them. The molecular instructions handbook of the mouse has been investigated more than any other mammal, with scientists turning off genes one at a time to determine their functions. Over time, the protocol became so well-defined that researchers began to feel sure that they could create an embryo from the start.

An extended pluripotent stem cell-based embryo was successfully created, implanted, and raised in a female mouse for the first time in 2019 by a research team at the University of Texas Southwestern Medical Center. While only 7% of embryos implanted successfully developed into a foetus, those that did often had severe birth defects. In the recent study, scientists at the Weizmann Institute have taken things further by creating artificial embryos in vitro or outside the womb.

They began by putting stem cells into a “naive” condition, from which they could differentiate into other types of cells. Some stem cells were genetically engineered to differentiate into cells for the placenta and yolk sac, while others were cultivated to develop into embryonic organs. The scientists spent over seven years constructing this intricate mechanical uterus that simulates the natural incubator of a mouse womb.

The artificial womb simulates a mother’s womb down to the tiniest detail, including the right amount of pressure, oxygen exchange, and nutrient flow for developing a mouse embryo. For over eight days, the synthetic embryo developed the basics of a nervous system, digestive system, and heart. Synthetic embryo gene expression patterns were 95% similar to their natural counterparts.

Previous attempts to cultivate embryos outside the womb in test tubes and dishes failed to maintain development for more than a few days at best. But most stem cell clusters never even got this far. After eight days, or about half of a mouse’s gestation period, just 50 out of about 10,000 synthetic embryos, or 0.5%, had fully developed. The high failure rate demonstrates how difficult and nuanced this process may be and how much more research is needed. Nonetheless, the new research is a huge step forward, and it may one day lead to the creation of fully functioning animals. With this information, doctors might cultivate fully functional human organs for transplantation in the lab, beginning with the patient’s mature cells.

In addition to helping reduce the use of animals in research, synthetic embryo models might become a reliable source of cells, tissues and organs for transplantation in the future. Instead of developing a different protocol for growing each cell type – for example, those of the kidney or liver – we may one day be able to create a synthetic embryo-like model and then isolate the cells we need. We won’t need to dictate to the emerging organs how they must develop.

The embryo itself does this best.This would guarantee perfect biocompatibility. We could also eliminate or drastically minimise the use of animals in scientific experiments Growing a synthetic embryo model solely from stem cells cultured in a petri dish could, to a large extent, help researchers avoid the technical and ethical issues involved in using human embryos in research and biotechnology.

Many feel that this is a prelude to developing synthetic human embryos in the near future. It’s crucial to think about whether or whether special permission is needed to use cells for this kind of study, which involves trying to recreate an embryo in a petri dish. More consideration should be given to who will have access to the results of this study, when that usage should occur, and who will be in charge of the research. Nonetheless, it must be acknowledged that a framework for regulating stem cell research already exists in the form of laws and international norms.

Allowing study utilising embryo models to increase our understanding of human development and developmental diseases that we can’t address any other way is distinct from allowing the use of this technology or technologies like cloning in humans for reproductive use. Progress in the scientific community is swift. Though largely in mice at this moment, we should now explore what this means for humans and decide where and how we draw the line as science progresses.