When the baby from Murfreesboro started showing cold symptoms and teething issues in late December, his mom, Jessica Chambers, said she initially didn’t think anything was out of the ordinary. However ...

Created from stem cells, without eggs, sperm, or a womb, the embryo model had a yolk sac and a proto-placenta, resembling a ...

Several thousand cells near the base of the yolk sac become very large, migrate individually into the gut mesoderm, up the mesenteries and invade the genital ridges. These are the primitive sex cells ...

The Philippine Eagle Foundation announced its first-ever documented unassisted natural hatching of a Philippine eagle, ...

The egg is a capsule that contains a developing animal and a yolk sac which the young gets its nutrition from. A capsule usually houses one embryo, but in some species there are multiple embryos per ...

A study identifies key risk factors for methotrexate failure in tubal ectopic pregnancy, highlighting the role of higher ...

During human foetal development, erythropoiesis first occurs in the yolk sac, then in the foetal liver and then, in the third trimester and after birth, in the bone marrow. Shortages of donor ...