How does a mycelium cell before fusion of mating types differ from one after fusion?

Before the fusion of mating types, a mycelium cell is typically haploid, containing a single set of chromosomes. After fusion occurs, the resulting cell becomes dikaryotic, meaning it now has two genetically distinct nuclei from each mating type, which coexist in the same cell without immediately fusing. This dikaryotic stage allows for genetic diversity and plays a crucial role in the life cycle of fungi, ultimately leading to the formation of spores during later stages of reproduction.