A University of Texas Southwestern (UTSW) research team has generated biological structures that resemble blastocysts--the structures that form from the early development of fertilized eggs in mammals. They did this using previously established human embryonic stem cells derived from embryos donated for research and human-induced pluripotent stem cells generated from adult cells-- collectively known as human pluripotent stem cells. The findings, published online on March 17, 2021 in Nature, could offer a new way to study early human development, pregnancy loss, and developmental defects. The Nature article is titled “Blastocyst-like structures generated from human pluripotent stem cells” (https://www.nature.com/articles/s41586-021-03356-y). Despite their similar morphology to blastocysts, blastocyte-like structures cannot develop into fetuses, says study leader Jun Wu (https://profiles.utsouthwestern.edu/profile/175076/jun-wu.html), PhD, an Assistant Professor of Molecular Biology at UTSW. “Having an in vitro biological model for blastocyst development is critically important to fill the gap for understanding human development without relying extensively on human embryos,” Dr. Wu says. Human pluripotent stem cells--cells at one of the earliest stages of development--have the potential to become nearly all of the body’s many tissue types. However, it was not known what molecular signals were important to get them to develop into blastocysts, hollow ball-shaped early embryos that form about five days after conception before implanting into the uterine wall. Studies of this stage of human development have largely relied on discarded/donated embryos from fertility treatments, a scarce resource that has ethical concerns, Dr. Wu says. Blastocysts contain three main cell types: epiblasts, hypoblasts, and trophoblasts.Login Or Register To Read Full Story