11th Class Biology Biological Classification And System Of Classification / जैविक वर्गीकरण और वर्गीकरण की प्रणाली Clamp Connection

In Basidiomycetes, the dikaryotic cells divide by clamp connections. They were first observed by Hoffman (1856) who named it as 'Schnallenzellen' (buckle-joints). A lateral pouch like outgrowth arises which projects downward like a hook. This pouch or clamp becomes almost parallel to the parent cell. The two nuclei now undergo conjugate division in such a way that one spindle lies parallel to the long axis of the cell and the other somewhat obliquely. As a result, one daughter nucleus enters into the clamp. Now, septae appear separating the clamp and the lower hyphal cell. The upper cell has both the nuclei. The clamp with a nucleus now fuses with the lower cell. The septum between the pouch and the lower cell is dissolved and thus the lower cell now contains both the nuclei of opposite strains. The entire process takes some 23-45 minutes.