Morphometric analysis of cucurbit mitochondria: The relationship between chondriome volume and DNA content

PROTOPLASMA ◽  
1984 ◽  
Vol 119 (1-2) ◽  
pp. 1-7 ◽  
Author(s):  
Arnold J. Bendich ◽  
Larry P. Gauriloff
1993 ◽  
Vol 41 (6) ◽  
pp. 829-836 ◽  
Author(s):  
M Derenzini ◽  
F Farabegoli ◽  
D Trerè

We studied the distribution of DNA in human circulating lymphocyte nucleoli using three different cytochemical methods for selective visualization of DNA in thin sections: the Feulgen-like osmium-ammine reaction, the NAMA-Ur procedure, and the osmium-ammine staining in glycine buffer, pH 1.5. All three methods indicated the presence of uniformly distributed, highly decondensed DNA filaments forming a large solitary agglomerate in the central part of the nucleolar area, corresponding to the solitary large fibrillar center (FC) as revealed by uranium and lead staining. We also studied the relationship between DNA agglomerates and nucleolar fibrillar components in resting and phytohemagglutinin (PHA)-stimulated lymphocytes by morphometric analysis of the areas occupied by these structures. In resting lymphocytes the mean area of the DNA agglomerates was 0.479 micron 2 +/- 0.161 SD, whereas that of FCs was 0.380 micron 2 +/- 0.149 SD, with a ratio of 1.26. In PHA-stimulated lymphocytes the mean area of the DNA agglomerates was 0.116 micron 2 +/- 0.056 SD, whereas that of the FCs was 0.075 micron 2 +/- 0.032 SD, with a ratio of 1.55. In PHA-stimulated lymphocytes we also measured the area occupied by the FCs plus the closely associated dense fibrillar component (DFC). The mean value of these two fibrillar components was 0.206 micron 2 +/- 0.081 SD. These data demonstrate that decondensed DNA filaments are uniformly distributed in the FCs and that in transcriptionally active nucleoli they are also present in the proximal portion of the DFC surrounding the FCs.


2019 ◽  
Vol 30 (2) ◽  
pp. 47-54
Author(s):  
M.R. Ferrari ◽  
E.J. Greizerstein ◽  
L. Poggio

In this work the relationship between genome size of Glandularia species and the meiotic configurations found in their hybrids are discussed. Glandularia incisa (Hook.) Tronc., growing in two localities of Corrientes and Córdoba provinces, Argentina, with different ecological conditions, showed inter-population variability of the 2C-value. The DNA content found in the Corrientes locality (2.41 pg) was higher than that obtained in the Córdoba locality (2.09 pg) which has more stressful environmental conditions than the former. These values are statistically different from those that were found in Glandularia pulchella (Sweet) Tronc. from Corrientes (1.43 pg) and in Glandularia perakii Cov. et Schn from Córdoba (1.47 pg). The DNA content of the diploid F1 hybrids, G. pulchella × G. incisa and G. perakii × G. incisa, differed statistically from the DNA content of the parental species, being intermediate between them. Differences in the frequency of pairing of homoeologous chromosomes were observed in the hybrids; these differences cannot be explained by differences in genome size since hybrids with similar DNA content differ significantly in their meiotic behavior. On the other hand, the differences in the DNA content between the parental species justify the presence of a high frequency of heteromorphic open and closed bivalents and univalents with different size in the hybrids. Key words: Intra-specific DNA content variability, homoeologous pairing, heteromorphic bivalents


1959 ◽  
Vol 37 (1) ◽  
pp. 763-774
Author(s):  
Dorothy S. Dow ◽  
C. E. Allen

Rate of body weight gain of both the young chick and the young rat was markedly inhibited following ingestion of amounts of thyroxine which were greatly in excess of physiological requirements. The rate of body weight gain of the young rat was also markedly inhibited in alloxan diabetes. The administration of insulin partly or largely prevented the observed effect on body weight in both conditions. The administration of thyroxine caused a reduction of rat skeletal muscle mass which was partially prevented when insulin was given concurrently with thyroxine.Reduced body weight gain and muscle mass in the rat were accompanied by marked increases in the muscle DNA and nuclei concentration. Nuclear diameter and the amount of DNA per nucleus remained unchanged. RNA concentration of the muscle was not reduced. The beneficial effect of insulin administration on body weight and muscle mass was accompanied by a preventive effect against changes in muscle DNA and nuclei concentration. However, since the DNA content of muscle bundles remained relatively unchanged and since muscle bundle weights changed proportionately with body weight it would appear that DNA content does not reflect change in muscle mass.The effectiveness of insulin in the thyroxine-treated animal appears to be due to an improved utilization of energy. A hypoglycemic action of thyroxine implies an antagonism between the two hormones in their mechanism of action. The relationship between the two hormones is not direct since the administration of insulin does not affect the increased plasma protein-bound iodine levels resulting from thyroxine treatment.


1995 ◽  
Vol 10 (1) ◽  
pp. 11-16 ◽  
Author(s):  
G. Saccani Jotti ◽  
M. Fontanesi ◽  
N. Orsi ◽  
L. Sarli ◽  
N. Pietra ◽  
...  

DNA content was determined by flow cytometry in a series of 51 paired fresh tissue samples of primary colorectal carcinomas and the respective non-neoplastic adjacent mucosa in order to assess the relationship between DNA ploidy and the most commonly used prognostic factors. Aneuploidy was observed in 70.6% of the tumors and more than one aneuploid peak was present in 3.9%. Aneuploid tumor frequency was higher in left (93.3%) and right colon (64.7%) cancers than in rectal carcinomas (60.0%), and multiple aneuploid clones were detected more frequently in men than in women and in patients with advanced disease (Dukes stage D). Non-neoplastic mucosa adjacent to aneuploid tumors showed aneuploidy in 4 out of 51 samples (7.8%). The mucosa adjacent to diploid cancers had only diploid characteristics. Polidy did not correlate with histological abnormalities. These findings suggest that DNA content as determined by flow cytometry needs further study with adequate follow-up to evaluate possible correlations with relapse-free and overall survival. Furthermore the aneuploidy of non-neoplastic mucosa provides evidence for a field defect in mucosa adjacent to colorectal cancer and supports the concept that this alteration may be of influence on carcinogenesis.


1985 ◽  
Vol 27 (6) ◽  
pp. 766-775 ◽  
Author(s):  
Arturo Martínez ◽  
Héctor D. Ginzo

There is a wide variation in the nuclear DNA content and chromosome size between the species belonging to the T. crassifolia and T. virginiana alliances (all the species but one are native to Central and North America). Also the DNA content per genome decreases when the ploidy level increases within the same specific polyploid complex with three ploidy levels (2x, 4x, and 6x). In contrast, no variation was found in the DNA content per genome between different ploidy levels in the T. fluminensis alliance (all the species are native to South America) where they range from 6x to 22x. Since all the species described here are perennials with various life forms, it was possible to analyze the relationship between the DNA content and their vegetative adaptation to the environment. The more specialized species (geophytes and hemicryptophytes) have a higher amount of DNA than the chamaephytes adapted to live in relatively more mesic regions. In the species living in Central and North America there is a positive correlation between the increase in DNA content and the latitude of their native regions.Key words: Tradescantia, DNA content, geographical distribution, life forms, polyploidy.


1987 ◽  
Vol 8 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Jelle W.F. Reumer ◽  
Charles-H. Thiébaud

AbstractThe relationship is studied between the volume of osteocyte lacunae and the nuclear DNA content and level of ploidy in the genus Xenopus. The lacunae volume and the DNA content appear strongly correlated. The possible use of this relationship in the study of the evolution of the genus is discussed.


1969 ◽  
Vol 13 (3) ◽  
pp. 241-250 ◽  
Author(s):  
G. J. Dowrick ◽  
A. S. El Bayoumi

1. The DNA contents of twenty-eight different species and forms of Chrysanthemum have been measured by photometry. It is shown that there are large differences in DNA content between some species with identical chromosome numbers.2. The DNA contents of natural polyploids are frequently not those expected when comparison is made with diploid forms of the same species. The DNA contents of induced polyploids are those expected.3. Chromosome length and volume are positively correlated with DNA content.4. The relationship between chromosome number, chromosome size, DNA content and gene number is considered, and it is suggested that the differences in DNA content may result from the presence of differing amounts of genetically inactive DNA in the chromosomes.


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