Peebles said processes like this are rare, though they could have some uses.
Without the shell in the way, researchers “can more directly observe the development of the embryo. So you can put it under a microscope, or do time-lapse photography, to observe the developmental process,” he said. “And you can more easily take DNA or protein samples.”
An article posted on Snopes.com links to a 2014 paper in the Journal of Poultry Science describing how a “shell-less” method for growing chickens from embryos could lead to research in “transgenic chickens, embryo manipulations, tissue engineering, and basic studies in regenerative medicine.”
But, Peebles noted, this process is not the sort of thing one would use in commercial chicken breeding, or in raising chickens for food. And it’s not easy.
Namely, it’s tricky to create an artificial environment sophisticated enough to replace a natural egg shell, which Peebles said is part food source, part protection, and also serves as a kind of filter for an embryonic chicken.
“What they are doing in an artificial environment is providing a protective coating that is semi-permeable so that water can be lost and gases can be exchanged,” Peebles said.
Shells provide minerals including calcium, magnesium, and manganese for the developing chick. Technicians would have to find a way to supplement those.
Shells also provide protection from bacterial infection, so they’d need a “very sanitary, aseptic environment in the laboratory,” and in the material used to house the shell-less egg.
The material also needs to be porous. Natural egg shells have pores all over them that allow oxygen to enter and carbon dioxide to exit. And as the embryo develops, it is digesting fat from the yolk and producing water, so the egg has to lose about 12 percent to 15 percent of its initial weight in water. That is common to all bird species, Peebles said, including penguins.
Researchers would also have to keep the shell-less egg warm, which they could do with an incubator, as shown in the video.
Of course, all this is easiest if one begins the process with a fertilized egg, Peebles said.
“If you can get closer to those conditions that nature provides,” he said, “then you will have more success.”