WASHINGTON – For the first time, scientists have used human cells to make structures that mimic the earliest stages of development, which they say will pave the way for more research without running afoul of restrictions on using real embryos.
Two papers published Wednesday in the journal Nature detail how two teams of scientists independently made such structures.
They stressed that their work is only for research, not reproduction, but it likely will pose new ethical questions.
“Studying early human development is really difficult. It’s basically a black box,” said Jun Wu, a stem cell biologist at the University of Texas, Southwestern Medical Center.
“We believe our model can open up this field,” he said, if “you can test your hypothesis without using human embryos.”
These balls, called blastocysts, form a few days after an egg has been fertilized but before the cells attach to the uterus to become an embryo. To differentiate their models from blastocysts created through fertilization, the researchers refer to the structures as “iBlastoids” and “human blastoids.”
“They shouldn’t be considered as equal to a blastocyst, although they are an excellent model for some aspects of biology,” said Jose Polo, an epigeneticist at Monash University in Australia who led the second research team.