Three-Clone Didymium Iridis Crosses and Plasmodial Incompatibility Phenotype

ABSTRACT

Heterokaryon formation between diploid plasmodia of the myxomycete Didymium iridis is controlled by a number of incompatibility loci. Normally, only plasmodia phenotypically identical for these loci will fuse to form a heterokaryon. Also, multiple myxamoebal (gametic) crosses which produce a number of plasmodia of different incompatibility phenotypes usually result in the final production of only a single phenotype (that displaying the strongest incompatibility reaction). However, if late log phase myxamoebae are crossed in specific proportions novel phenotypes can be obtained for a number of gametic combinations. These phenotypes are apparently the combined expression of two normally incompatible phenotypes.

Key Words:

• Myxomycetes
• heterokaryon
• incompatibility