Question

Difference between monokaryotic and dikaryotic

Answer 1

First of all, as the names already suggest, monokaryotic hyphae have only one cell nucleus and dikaryons have two cell nuclei (“mono” meaning “one”, and “karyon” meaning “nut”, “kernel” or, in this sense, “core” or “nucleus”). Dikaryons originate from two monokaryons that fused together and exchanged cell nuclei. This means they also have to maintain two different nuclei, instead of one and requires different or additional cellular machinery.

Dikaryons are also different in the sense that the transcriptional and translational activity are not that much higher compared to monokaryotic mycelium, despite having twice the amount of DNA. Dikaryons are tightly regulated so that the total number of ‘active genes’ in both nuclei are not double the amount of those in one nucleus. Maybe you could imagine that having double the amount of every protein/enzyme in one cell might scramble up many cellular processes, like cell division or signaling.

Dikaryotic mycelium may sometimes have a slightly different appearance (at least on agar medium) than their respective monokaryons, depending on the species. An example is the fungus Panellus stipticus (own observations).Monokaryotic mycelium of this species looks the same at almost every point of the cultures. Dikaryotic mycelium, however, grows somewhat different: the colonies are a lot more ‘fluffy’ and there are curved ‘grooves’/indentations originating from the center of the colony. I have no clue why the dikaryotic colonies grow in such a strange way compared to monokaryons, but there’s obviously a difference.

Answer 2

In some species the correct mating types of hyphae cells can fuse then there is a heterokaryotic stage in which cells have haploid nuclei from two parents and are dikaryotic. Dikaryotic cell has two genetically distinct nuclei 


Fungi are Eukaryotic with membrane bound organelles including a nucleus. 

Bacteria are the much smaller Prokaryotic Domains. These species do not have membrane bound organelles so have no nucleus.