Development of mucosal mast cells after injection of a single connective tissue-type mast cell in the stomach mucosa of genetically mast cell-deficient W/Wv mice.

Mast cells may be classified into at least two phenotypically distinct populations: connective tissue-type mast cells (CTMC) and mucosal mast cells (MMC). Mast cells in the peritoneal cavity of mice are typical CTMC, whereas mast cells in the mucosa of the stomach show morphologic characteristics of MMC. We investigated whether CTMC may change to MMC. A single peritoneal mast cell of WBB6F1-+/+ mice was identified under the phase-contrast microscope, picked up with the micromanipulator, and injected into the stomach wall of genetically mast cell-deficient WBB6F1-W/Wv mice. The cells with histochemical and electron microscopical features of MMC developed in the mucosa, and those with histochemical features of CTMC in the muscularis propria. This directly demonstrates that a certain proportion of CTMC may function as a bipotent precursor for both MMC and CTMC.