Some newly reported clumps of cells growing in lab dishes have been hailed as the closest things to human embryos that scientists have ever made in the lab, according to Science News. These entities are human embryo models - masses of cells created from stem cells that mimic some properties of certain stages of embryo development. The achievement gives researchers a chance to look at human development beyond the first week or so, when an embryo must implant in the uterus to develop further. That post-implantation stage hadn't been re-created in lab dishes - until now. Six studies reported in June and July describe the embryo models, which have generated excitement and concern in equal measure. For researchers working on these embryo models, the faux embryos are new tools to gain insight into the 'black box' of human development, after embryos implant in the uterus. They are useful because donated human embryos are in short supply, and there are limits on the types of experiments researchers can perform on them. About 60 percent of pregnancies fail just before, during or soon after implantation, developmental and stem cell biologist Magdalena Zernicka-Goetz of the University of Cambridge and Caltech said June 27 during a news briefing discussing an embryo model made in her lab. Insights gleaned from the embryo models may give new understanding of why many pregnancies fail to take hold and lead to better fertility treatments, Zernicka-Goetz said. But others worry that the models - along with eggs and sperm made from stem cells - raise the specter of researchers using the mimics to create babies. Scientists developing the models say reproduction is not their aim or intention, and that implantation in a uterus is impossible with these embryo models. Still, the research raises issues of how to - and whether to - regulate what scientists can do with embryo-like entities made from stem cells. Questions surround whether embryo models could or should be grown past the equivalent of 14 days of normal human development after fertilization. And critics warn that overstating what the models are or can do could risks damaging trust in science.

Source: Azerbaijan State News Agency