Presence of mast cell precursors in fetal liver of mice

When liver cells obtained from 13- to 18-day embryos of beige (Chediak-Higashi syndrome) mice were transplanted into irradiated normal adult mice, tissue mast cells with giant granules showing beige mouse origin developed in the normal recipient mice. Mast cell precursors seem to have developed earlier in the liver of embryos than mast cells themselves since no mast cells were detectable in any tissues of 13- and 14-day embryos. This result suggests that tissue mast cells originate from hematopoietic tissues not only in adult mice but also in mouse embryos.