Syncrasis

Syncrasis is a term used in biology with several meanings tied to the idea of mixing or fusion of cellular material. The word comes from Greek syn- "together" and krasis "mixing."

Historically, some cytologists used syncrasis to describe the fusion of adjacent protoplasts to form a multinucleate cell, or syncytium, particularly during certain developmental stages or in some tissues.

In other contexts, syncrasis has referred to a rearrangement or intermingling of chromatin during meiosis or embryogenesis. In modern usage, the term is rarely employed and its definitions vary; many authors have replaced it with terms such as synapsis, chromatin remodeling, or coalescence, depending on the organism and process.

Because of its inconsistent usage, readers should verify the definition in the specific study and organism. See also synapsis, chromatin remodeling, and syncytium for related concepts.