Interactions between five homokaryotic mycelia of Termitomyces sp . Homokaryon codes (A to E) are given along the axes. Distinct zones with increased growth are visible where two different homokaryotic mycelia meet. These zones with increased growth remain local and do not spread across the mycelia. Genetic analysis shows that only the interaction zone has become heterokaryotic, meaning that there is no nuclear migration throughout the homokaryons. Pairings between identical homokaryons are along the diagonal, and do not show these interaction zones.