Determination of nuclear DNA content in fungi using mithramycin: vegetative diploidy in Armillaria mellea confirmed

1983 ◽  
Vol 29 (9) ◽  
pp. 1179-1183 ◽  
Author(s):  
A. L. Franklin ◽  
W. G. Filion ◽  
J. B. Anderson

Armillaria mellea, a phytopathogenic fungus, is the only member of the Agaricales (Basidiomycetes) whose fertile vegetative phase in nature is thought to be diploid, rather than dikaryotic. To examine the vegetative ploidy of A. mellea, we used the DNA-binding antibiotic, mithramycin, for fluorometry of in situ nuclear DNA. The measurements of nuclear DNA content indicated that strains derived from single basidiospores of A. mellea were haploid and that strains derived from matings of isolates of single spores were diploid. These data confirm the results of earlier genetic experiments, which show haploidy and diploidy in unmated and mated strains, respectively. Nuclear DNA measurements in known haploid and diploid strains of Aspergillus nidulans confirmed the validity of our protocol.


2004 ◽  
Vol 16 (3) ◽  
pp. 301 ◽  
Author(s):  
Karl Klisch ◽  
Preben D. Thomsen ◽  
Vibeke Dantzer ◽  
Rudolf Leiser

The frequency of polyploidisation in bovine binucleate trophoblast giant cells (TGC) from placentomes (PL) and the interplacentomal allantochorion (AL) of six male fetuses with a crown–rump length between 3.5 and 103 cm was determined by in situ hybridisation with a chromosome-7-specific probe, using a probe specific for the Y chromosome to distinguish between maternal and fetal nuclei. The results showed that polyploid nuclei were essentially always of fetal origin. The frequency of tetraploid nuclei varied between 3% and 15% in both the placentomal and interplacentomal samples, with mean frequencies of 8.8% and 10.0% respectively. Octoploid nuclei were observed with a mean frequency of 1.1% in the interplacentomal samples, but were absent in samples from placentomes. Subsequent determination of nuclear DNA content by cytophotometric measurement of Feulgen-stained nuclei revealed that the frequency of nuclei with an 8C DNA content was several fold higher (AL 5.4%; PL 7.8%) than the frequency of octoploidy, suggesting that tetraploid TGC cells are arrested in the G2 phase of the cell cycle.



1985 ◽  
Vol 27 (1) ◽  
pp. 47-50 ◽  
Author(s):  
J. B. Anderson ◽  
D. M. Petsche ◽  
A. L. Franklin

The relative nuclear DNA contents of haploid, diploid, and benomyl-induced segregants of diploid strains of the phytopathogenic fungus Armillaria mellea were measured by mithramycin staining and fluorescence photometry. The diploid strains, originally recovered from sexually compatible matings of haploid strains, were heterozygous at mating-type and auxotrophic marker loci. The somatic segregants examined here were derived by treatment of the diploid strains with the fungicide benomyl in previous studies. As expected, the diploid strains had approximately twice as much nuclear DNA as the haploid strains. Most segregants had near-haploid DNA contents and no detectable heterozygosity at the marker loci; these strains were most likely true haploids. Other segregants with near-haploid DNA contents were heterozygous at a marker locus indicating that they were aneuploid. A minority of segregants had near-diploid DNA contents and may have been either aneuploid or diploid.Key words: basidiomycetes, mithramycin, parasexuality.



1988 ◽  
Vol 7 (1) ◽  
pp. 74-77 ◽  
Author(s):  
Jan Fahleson ◽  
Johan Dixelius ◽  
Eva Sundberg ◽  
Kristina Glimelius


1989 ◽  
Vol 100 (2) ◽  
pp. 95-98 ◽  
Author(s):  
Yang-Chun Guo ◽  
Lawrence Desanto ◽  
Gregory V. Osetinsky

The nuclear DNA content was measured in formalin-fixed and deparaffined specimens of 296 oral, pharyngeal, and laryngeal squamous cell carcinomas from patients in whom the clinical outcome was known. One hundred ninety (64%) contained cells with abnormal DNA (DNA aneuploid or tetra/polypoid). Only 32% (60 of 190) of the patients with DNA nondiploid cancers survived 5 years, compared with 49% (52 of 106) of the patients with DNA diploid cancers. When the findings were controlled for clinical stage, patients whose tumors were DNA diploid had a survival advantage at each stage. Histologic grading showed less correlation, because only patients with well-differentiated carcinomas had a survival advantage if their tumors were DNA diploid. These data showed that determination of DNA content in cancers of the head and neck can offer prognostic information not provided by other means and enhance the diagnosis of cancer.



HortScience ◽  
1996 ◽  
Vol 31 (3) ◽  
pp. 322c-322
Author(s):  
W.E. Jones ◽  
A.R. Kuehnle ◽  
K. Arumuganathan

Flow cytometry (FC) has proven to be an efficient and reliable method to estimate nuclear DNA content (genome size) in quantifiable units useful for genetic and molecular biology studies. This method also makes possible determination of the variation in nuclear DNA content between related taxa, which gives insights into the process of speciation. In this study, DNA content was determined in nuclei isolated from leaves of 21 Dendrobium species representing each of the major taxonomic groups used in the Univ. of Hawaii breeding program. Nuclei were mechanically isolated, stained with the nucleic acid-specific fluorochrom propidium iodide, and DNA content determined using a Coulter Epics 753 laser flow cytometer. Chicken erythrocyte nuclei (2C = 2.33 pg DNA) were used as an internal standard for direct comparative measurement. The mean diploid genome (2C) values for Dendrobium species ranged from 3.36 to 5.06 pg. Genome sizes were evaluated for possible use as discrete characters for taxonomic group assignment and compared to previous data on breeding compatibility and evolutionary relationship between species.





Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 258-265 ◽  
Author(s):  
I. Galasso ◽  
D. Pignone ◽  
M. Frediani ◽  
M. Maggiani ◽  
R. Cremonini

The karyotypes of three accessions, one each from three annual species of the genus Cicer, namely Cicer arietinum, Cicer reticulation, and Cicer echinospermum, were examined and compared using C-banding, the fluorochromes chromomycin A3, DAPI, and Hoechst 33258, in situ hybridization of the 18S–5.8S–25S and 5S rDNA sequences, and silver staining. The nuclear DNA content of the three species and the amount of heterochromatin were also determined. The results suggest an evolutionary pathway in which C. reticulatum is the ancestral species from which both C. arietinum and C. echinospermum are derived with the loss of one pair of satellites; subsequently, C. echinospermum further differentiated by the accumulation of chromosomal rearrangement(s) that gave rise to a hybrid sterility barrier. Key words : Cicer, C-banding, fluorochromes, Ag staining, rRNA genes.





Cancer ◽  
1973 ◽  
Vol 31 (6) ◽  
pp. 1553-1560 ◽  
Author(s):  
Arthur S. Ludwig ◽  
Takashi Okagaki ◽  
Ralph M. Richart ◽  
Raffaele Lattes


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