What does the coat color chimerism tell you about the animal?
Coat color chimerism indicates that individual ES cells were incorporated into the ICM of the blastocyst following microinjection and that, once incorporated, were capable of giving rise to various cells or tissues in the resulting animal. As both germ cells and melanocytes (pigment producing cells of the skin, hair and eyes) arise from migratory precursor cell populations within the developing embryo, the percent of 129 ES cell derived coloration in the coat is often correlative with the inheritance of ES cell-derived germ cells. For example, 129P2/Ola derived chimeras have marbled coats (and skin) of chinchilla, white and agouti (Mouse Strain Coat Colors). Thus, the higher percentage of ES cell derived coat coloration, or chimerism, the greater the likelihood that the incorporated ES cells were also able to generate germ cells that migrated to and populated the germinal ridges. Coat color chimerism and germline transmission is less correlative with C57BL/6 ES cell lines.
