A method of differentiation from an embryonic stem cell of a primate into
a hematopoietic cell, comprising maintaining an embryonic stem cell of a
primate under conditions suitable for induction of differentiation into a
hematopoietic cell, transplanting the resulting cell into a fetus in a
uterus of a pregnant sheep, rearing the fetus, administering a cytokine
specific for a primate to a born lamb, and obtaining a hematopoietic cell
of a primate from a sheep obtained by rearing the lamb, a method for
producing a hematopoietic cell of a primate, a hematopoietic cell
obtained by the method, and a method for producing a chimeric sheep which
produces a hematopoietic cell of a primate, comprising maintaining an
embryonic stem cell of a primate under conditions suitable for induction
of differentiation into a hematopoietic cell, and transplanting the
resulting cell into a fetus in a uterus of a pregnant sheep. According to
the present invention, it becomes possible to develop a means for
treating a disease or a condition requiring construction of a
hematopoietic system or an action of a hematopoietic cell.