title: Genetic and morphological study of aggregation in the cellular slime mold Polysphondylium violaceum.
abstract: A system for genetic analysis in the cellular slime mold P. violaceum has been developed. Two growth-temperature-sensitive mutants were isolated in a haploid strain and used to select rare diploid heterozygotes arising by spontaneous fusion of the haploid cells. A recessive mutation to cycloheximide resistance in one stain enables selection of segregants, which often appear to be aneuploid.-Aggregation-defective (ag-) mutants having a wide range of phenotypes were isolated in both temperature-sensitive strains after nitrosoguanidine treatment, and complementation tests were performed between pairs of these mutants. Of 380 diploids isolated, 32 showed defective aggregation and were considered to contain 2 noncomplenting ag- mutations. Among noncomplementing mutants interallelic complentation is common. Noncomplementing mutants fall into 4 complementation groups, and those within each complementation group are phenotypically similar. Statistical analysis of the results suggests that the number of complementation units involved in aggregation is about 50.
mesh_terms: D000483:Alleles; D002449:Cell Aggregation; D003513:Cycloheximide / Q000494:pharmacology; D005796:Genes; D005816:Genetic Complementation Test; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D009153:Mutagens; D009154:Mutation; D009235:Myxomycetes / Q000187:drug effects / Q000302:isolation & purification*; D010641:Phenotype; D011003:Ploidies
chemical_list: D009153:Mutagens; D008769:Methylnitronitrosoguanidine; D003513:Cycloheximide