mononucleated

Mononucleated describes a cell that contains a single nucleus. This is the usual condition for most somatic cells and contrasts with multinucleated cells, which harbor two or more nuclei within a shared cytoplasm. A mononucleated cell may be diploid, with one complete genome per nucleus, or polyploid, where the single nucleus contains multiple genome copies. Multinucleation can arise through cell fusion or through endomitosis, a process in which the nucleus replicates its DNA without cell division.

Common examples of mononucleated cells include many epithelial cells, neurons, fibroblasts, lymphocytes, and other mature somatic cells in animals and plants. Red blood cells in mammals lack a nucleus and therefore are not considered mononucleated. Hepatocytes frequently are binucleated and may be polyploid, illustrating that a cell can be polyploid without having multiple nuclei. In contrast, skeletal muscle fibers and osteoclasts are examples of multinucleated cells.

In histology and pathology, the number of nuclei per cell is used as a diagnostic and descriptive feature. The predominance of mononucleated cells helps define tissue type; instances of multinucleation can indicate specialized function, development, or disease processes. The term mononucleated is often used interchangeably with uninucleate or mononuclear in scientific literature.