Genetic Control of Sporulation in the Blue-green Alga Anabaena Doliolum Bharadwaja

Two genetically distinct, non-sporulating mutant strains of Anabaena doliolum were isolated following exposure of the alga to ultraviolet radiation. Among the progeny of a cross between the two non-sporulating strains, some filaments were able to sporulate. The spores of such filaments were of two types. Type 1 upon germination produced the parental phenotype, type 2 gave rise to wild phenotype. This suggests the involvement of heterozygosity in genetic recombination in A. doliolum. The results further indicate that the formation of spores in this alga is under the control of more than one genetic determinant, and that nuclear segregation occurs during sporulation.