A hematopoietic stem found in the yolk sac. In mice, this cell type is Sca-1-negative, CD45-negative, MHC-negative, HSA-positive, AA4.1-positive, CD44-positive. [ GOC:tfm doi:10.1097/MOH.0b013e3282f97ae1 ]

Synonyms: hemangioblast precursor