Shahriari (2008).Comparison of random amplified polymorphic DNA markers and morphological characters in identification of homokaryon
isolates of white button mushroom (Agaricus bisporus).
In the model, a homokaryon with only (parasitic) h nuclei is assumed to have a fitness 1 - s (0 [less than] s [less than] 1), whereas h + H heterokaryons and H homokaryons have a fitness I.
Provided that heterokaryons form only with direct neighbors, and there are n potential neighbors, an individual remains a homokaryon (consisting of one haploid genotype) when it has no compatible neighbors, or forms a heterokaryon consisting of 2, 3, .
Homokaryons with only h nuclei have a fitness disadvantage compared to homokaryons with only H nuclei.
In result of this, may form dikaryons_heterokaryons (cells with nuclei of different type of cells) or homokaryons
(cells with homogenous nuclei) in the process of fusion with one another or with other cells, and then, in case of synchronous mitosis or mechanical reunification of nuclei, they may form synkaryons (mononuclear hybrid cells), with tetraploid or hypoteteraploid sets of chromosomes on initial stage of hybridization.
Differentiation of homokaryons
and heterokaryons of Agaricus bisporus with inter-simple sequence repeat markers.
We spend a lot of time in the lab trying to obtain cells that are called homokaryons. The cells of Agaricus bisporus have two compatible nuclei, often referred to as the "A nucleus" and the "B nucleus".
In a nutshell, mushroom breeding is the combination of compatible homokaryons in new or novel ways.
Fritsche's breeding program combined homokaryons from both the white and off-white strains in an attempt to produce a hybrid exhibiting the best qualities of each strain.
Genetic improvement can be achieved by chemical and physical mutation, sexual hybrids, homokaryons
, and genetic manipulation e.g, directed mutagenesis, protoplast fusion, genetic analysis of fusants; recombination, transformation or isolation of useful genes from biocontrol fungi without functional sexual stages (Mohamed et al., 2004 and Palumbo et al., 2005).