kernlose

Kernlose is a term used in biology, especially in German-language texts, to describe cells or cellular structures that lack a true cell nucleus. The word is formed from Kern (nucleus) and los (without). In English literature, the terms anucleate or enucleated are usually used.

In practice, kernlose cells include mature mammalian erythrocytes, which lose their nucleus during maturation, resulting in biconcave, nucleus-free red blood cells. This enucleation increases hemoglobin capacity and enables greater deformability as the cells traverse narrow capillaries. Platelets are also kernlose; they are small, anucleate cytoplasmic fragments derived from megakaryocytes and circulate without a nucleus.

Not all organisms have kernlose cells. In birds, reptiles, amphibians, and many fish, erythrocytes retain their nuclei, so those species lack kernlose red blood cells. Other kernlose cell types include certain lens fiber cells of the eye and some cell populations during development, where nuclei are degraded or extruded to achieve specialized functions such as optical transparency or rapid cytoplasmic activity.

The term is primarily used descriptively and historiographically; modern histology often favors anucleate or enucleated as English equivalents. Related concepts include enucleation, anucleate cell, and the broader category of cytoplasmic enucleation in cell differentiation.

See also: Anucleate, Enucleation