Macrophage localization in the developing lens primordium of the mouse embryo – An immunohistochemical study

In mammals, macrophages are known to play an important role in lens development. Macrophages in the embryonic lens are positive for F4/80 monoclonal antibody, and, from 10.5 days to 12 days of gestation, numerous macrophages were observed in the ectoderm, lens vesicle, lens cavity and surrounding mesenchymal tissue, phagocytosing and removing degenerating epithelial cells. During primary lens fiber differentiation, the narrowing lens cavity contained numerous macrophages. Most of the macrophages in the cavity attached to the anterior epithelial wall of the lens vesicle, but a few macrophages were found within the lens epithelial cell layer. Conversely, the thickening posterior wall of the vesicle did not contain any positive cells. After the lens cavity was filled, intralental positive cells disappeared. These characteristic localizations of macrophages in the developing lens to remove apoptotic dead cells may indicate that cell death took place mainly in the anterior wall of the lens vesicle, that is, in the lens epithelium.