NUCLEAR DNA CONTENT OF MYXAMOEBAE AND PLASMODIA IN SIX NON‐HETEROTHALLIC ISOLATES OF A MYXOMYCETE, DIDYMIUM IRIDIS

A B S T R A C T The nuclear DNA content of six non-heterothallic isolates of the myxomycete Didymium iridis was measured by combining the Feulgen reaction with absorption microspectrophotometry. This allowed us to distinguish between homothallic (sexual) and apogamic (non-sexual) isolates. Four of the isolates studied, Panamanian 4 and 5, California 1, and Missouri 1 are homothallic. Moreover, the average DNA content of the myxamoebal and plasmodial nuclei (0.32 and 0.61 respectively) does not differ significantly from the calculated haploid and diploid values for heterothallic isolates of D. iridis (0.34 and 0.63). Hence, it is concluded that in each of these isolates the myxamoebae are haploid and the plasmodia diploid. In two of the isolates investigated, Georgia 1 and Hawaii 1, the DNA content of the myxamoebal and plasmodial nuclei did not differ significantly. Therefore, in both of these isolates the plasmodia appear to develop apogamically. In addition the mean DNA values recorded for the Ha-1 isolate suggest that it is aneuploid.

[1]  O. R. Collins,et al.  CYTOPHOTOMETRIC MEASUREMENT OF NUCLEAR DNA IN SEVEN HETEROTHALLIC ISOLATES OF DIDYMIUM IRIDIS, A MYXOMYCETE , 1976 .

[2]  O. R. Collins,et al.  Apogamic induction of haploid plasmoida in a myxomycete, Didymium iridis. , 1976, Developmental biology.

[3]  O. R. Collins.  HETEROTHALLISM AND HOMOTHALLISM: A STUDY OF 27 ISOLATES OF DIDYMIUM IRIDIS, A TRUE SLIME MOLD' , 1976 .

[4]  P. Adler,et al.  Mating type and the differentiated state in Physarum polycephalum. , 1975, Developmental biology.

[5]  O. R. Collins.  Mating Types in Five Isolates of Physarum Polycephalum , 1975 .

[6]  C. Therrien,et al.  Nuclear DNA Content and Ploidy Values in Clonally-Developed Plasmodia of the Myxomycete Didymium Iridis , 1975 .

[7]  D. Cooke,et al.  Plasmodium formation without change in nuclear DNA content in Physarum polycephalum. , 1974, Genetical research.

[8]  C. Therrien,et al.  COMPARATIVE MEASUREMENTS OF NUCLEAR DNA IN A HETEROTHALLIC AND A SELF‐FERTILE ISOLATE OF THE MYXOMYCETE, DIDYMIUM IRIDIS , 1974 .

[9]  H. P. Rusch,et al.  Nuclear DNA content and chromosome numbers in the myxomycete Physarum polycephalum. , 1973, Developmental biology.

[10]  C. Therrien,et al.  QUANTITATIVE MICROSPECTROPHOTOMETRY OF NUCLEAR DNA IN SELFING STRAINS OF THE MYXOMYCETE DIDYMIUM IRIDIS , 1972 .

[11]  O. R. Collins,et al.  Clonally-produced plasmodia in heterothallic isolates of Didymium iridis. , 1968, Mycologia.

[12]  C. Therrien.  MICROSPECTROPHOTOMETRIC MEASUREMENT OF NUCLEAR DEOXYRIBONUCLEIC ACID CONTENT IN TWO MYXOMYCETES , 1966 .

[13]  O. R. Collins.  HETEROTHALLISM AND HOMOTHALLISM IN TWO MYXOMYCETES , 1961 .