coenocyt

A coenocyt, more commonly called a coenocyte, is a multinucleate cell arising when nuclei divide but the cytoplasm does not divide through cytokinesis. In such cells, a single continuous cytoplasmic mass contains many nuclei that may be distributed throughout the cell.

Coenocytes form through repeated rounds of nuclear division without corresponding cytokinesis (mitosis without cytokinesis). They can also arise, in some contexts, by cell fusion or by endomitosis, where nuclear divisions occur without cell division and without normal cytoplasmic division. The result is a large cell with multiple nuclei sharing one cytoplasm.

Coenocytic organization occurs in a variety of organisms. Plasmodial slime molds (for example, Physarum) create large, branching plasmodia that are coenocytic. Many fungi possess coenocytic hyphae, known as aseptate hyphae, in which the cytoplasm is continuous along the hypha with numerous nuclei. Some algae, particularly siphonous green algae such as Caulerpa and Valonia, also exhibit coenocytic thalli where numerous nuclei share a single cytoplasmic network. In addition, certain plant and animal tissues can be multinucleate through specialized development, though these are often termed syncytial rather than coenocytic.

The coenocytic mode can facilitate rapid growth and efficient cytoplasmic transport, since nutrients and organelles can move freely within a single cytoplasmic continuum. However, the large, undivided cytoplasm can also pose challenges for cellular regulation and response to damage.

In summary, a coenocyt or coenocyte is a multinucleate cell formed by nuclear division without cytokinesis, seen in diverse taxa from fungi to algae to slime molds, and characterized by a single, continuous cytoplasm housing multiple nuclei.