Trembling with life, developing mice movesee very slightly in their vials. Only few days since they were fertilized, the rodent embryos were lower case-smaller than an aspirin tablet—But his Existence a is a monumental feat: they developed in an artificial womb, a novelty in early mammalian science and a major step in improving scientists’ understanding of embryonic development.
The investigation, published Today in the journal Nature, he describes how scientists took new embryos and developed them over the course of six days, about one-third of the mouse’s total gestation period, outside the uterus of a rodent.
“If you give an embryo the right conditions, its genetic code will function like a preset line of dominoes, arranged to fall one after the other,” said co-author Jacob Hanna, a developmental biologist at the Weizmann Institute of Sciences in Israel, at an institute. of Sciences Weizmann release. “Our goal was to recreate those conditions, and now we can see, in real time, how each domino hits the next in line.”
For almost a century, scientists have worked with the idea of taking the embryonic development of mammals out of the womb, to better understand how our cells come together and rapidly transform into organisms. For much of that time, however, delving into the early stages of that development has been a black box; later stages can be more easily simulated, as they were in 2017, when one group used a bag-like device to hatch lambs for their delivery in Philadelphia.
Two years later, that same team Announced They could keep preterm fetal lambs alive in an artificial room.megabyte. After delivery, the The premature mammals appeared as healthy as their counterparts in time.. “In the world of artificial placenta technology,” said one of the study authors at the time, “we have indeed exceeded the 4 minute mile.”
Those lambs were much more developed than the newly observed mice. The germ stages of the entire life span of mammals are difficult to observe in utero, so biologists and geneticists previously pieced together an idea of what happens by combining observations, such as looking at the external eggs of amphibians and comparing them to images of dissected mouse embryos. Recent work changes that.
The initial mouse embryos consisted of only a few hundred cells and were placed on laboratory plates mimicking the uterine wall. After a couple of days, the team moved the embryos into beakers filled with a nutrient solution and regulated the amounts of oxygen and carbon dioxide and the pressure of the embryos’ new environment.ent. After about six days, the growth of the embryos was unsustainable and they were destroyed before they reached full term.
There are a couple of obstacles Hanna hopes they will face next: TThe embryos needed a blood supply, and it had yet to be fertilized and cultivated initially in a rodent uterus. In future experiments, Hanna hopes to somehow incorporate artificial blood and synthesize embryos from stem cells to completely avoid the need for a biological uterus.
The new research was published in conjunction with other role in nature today; That work describes an early human embryo model generated from skin cells. The research team was able to reprogram human skin cells into blastocyst-like structures, the embryonic stage that occurs about five days after the fertilization of an egg. The synthetic structures, called iBlastoids (as through a strange collaboration between Apple and Pokémon), have significant implications for understanding infertility, conditions that cause miscarriages, and other aspects of early human development.
“IBlastoids will allow scientists to study the early steps of human development and some of the causes of infertility, congenital diseases, and the impact of toxins and viruses on early embryos,” said co-author José Polo, developmental biologist. from Monash University in Australia to a university Press release, “Without the use of human blastocysts and, more importantly, on an unprecedented scale, accelerating our understanding and the development of new therapies.”
Just as watching repeats of races will inform a runner on how to improve their technique, being able to replicate and observe the primary stages of mammalian life will often help scientists. understand how to improve living conditions in the beginning.