The yolk sac is the lone site of primitive hematopoiesis. However, the role of the yolk sac in generating definitive hematopoietic progenitors has remained controversial since the onset of circulation ...

Gastrulation, the process where an embryo reorganizes itself from a hollow sphere into a multilayered structure, is considered a 'black box' of human development. This is because human embryos are ...

Mouse embryonic stem cells (ESCs) and extraembryonic trophoblast stem cells (TSCs) have been combined in a 3D scaffold to generate structures whose morphogenesis is remarkably like that of natural ...

HeX-Embryoid model showing early blood cells (green) that have formed inside of blood vessels (red) surrounded by yolk sac mesoderm cells (blue) that support these tissues. University of Pittsburgh ...

Scientists have been able to create stem cells that can mimic the early stages of mouse development. The researchers used only reprogrammed stem cells, not a fertilized egg, to create a synthetic ...

Epidemiology and Infection, Vol. 103, No. 3 (Dec., 1989), pp. 577-585 (9 pages) Graded doses of live and heat-killed cells of Campylobacter jejuni were injected into the yolk-sac of 5-day-old chick ...

Pluripotent stem cells can develop into most tissues of the organism, but they cannot develop into extra-embryonic tissue -- the placenta or yolk sac, for example --- like the one-celled fertilized ...

Isolated from its mother's body, a chicken embryo's only source of food is a golden-yellow dollop of nutrients known simply as yolk. Sustained by the placenta, mammals like ourselves have no need for ...

In a longitudinal study published in Scientific Reports, researchers investigate the effect of maternal physical activity on the size and growth of the yolk sac during early pregnancy. To this end, ...

Cellular aggregates derived from human stem cells in previous studies could not be considered genuinely accurate human embryo models, because they lacked nearly all the defining hallmarks of a ...

Do synthetic mice dream of electric sheep? We’re on the way to finding out thanks to a breakthrough in stem cell research. It’s not going to overthrow mankind from a lab anytime soon, but a stell cell ...