Genome size in Arachis duranensis: a critical study

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 826-830 ◽  
Author(s):  
Eva M Temsch ◽  
Johann Greilhuber

Arachis duranensis is a diploid wild relative of the tetraploid cultivated peanut Arachis hypogaea. The literature indicates two 2C genomic DNA mean values (genome size) for A. duranensis, 4.92 and 5.64 pg, and intraspecific variation of up to 11% negatively correlated with altitude above sea level of the collection sites has been reported. Our recent investigations of Arachis species have shown that unrecognized technical problems with peanut material may have influenced previous genome-size data and rendered them open to critical comments. In the present study, 20 accessions of A. duranensis were investigated by means of DNA flow cytometry (propidium iodide staining) and several of these also by Feulgen DNA image analysis. Pisum sativum was used as the internal standard (2C = 8.84 pg). 2C values in A. duranensis were about half those described previously and varied between 2.49 and 2.87 pg (flow cytometry). This variation was statistically significant and reproducible. There was a negative correlation of genome size with latitude and altitude above sea level of the collection sites. Such a correlation had been already found in one of the previous studies. However, the incongruences between the absolute DNA content values obtained in the present investigation and those in the literature point to the importance of carrying out methodological studies on best practice in DNA-content determinations in plants.Key words: Arachis duranensis, genome size, flow cytometry, Feulgen densitometry.

2005 ◽  
Vol 95 (4) ◽  
pp. 309-312 ◽  
Author(s):  
J.K. Brown ◽  
G.M. Lambert ◽  
M. Ghanim ◽  
H. Czosnek ◽  
D.W. Galbraith

AbstractThe nuclear DNA content of the whitefly Bemisia tabaci (Gennnadius) was estimated using flow cytometry. Male and female nuclei were stained with propidium iodide and their DNA content was estimated using chicken red blood cells and Arabidopsis thaliana L. (Brassicaceae) as external standards. The estimated nuclear DNA content of male and female B. tabaci was 1.04 and 2.06 pg, respectively. These results corroborated previous reports based on chromosome counting, which showed that B. tabaci males are haploid and females are diploid. Conversion between DNA content and genome size (1 pg DNA = 980 Mbp) indicate that the haploid genome size of B. tabaci is 1020 Mbp, which is approximately five times the size of the genome of the fruitfly Drosophila melanogaster Meigen. These results provide an important baseline that will facilitate genomics-based research for the B. tabaci complex.


Gut ◽  
2017 ◽  
Vol 67 (7) ◽  
pp. 1229-1238 ◽  
Author(s):  
Won-Tak Choi ◽  
Jia-Huei Tsai ◽  
Peter S Rabinovitch ◽  
Thomas Small ◽  
Danning Huang ◽  
...  

ObjectiveThe diagnosis of dysplasia in Barrett’s oesophagus (BO) can be challenging, and reliable ancillary techniques are not available. This study examines if DNA content abnormality detected by flow cytometry can serve as a diagnostic marker of dysplasia and facilitate risk stratification of low-grade dysplasia (LGD) and indefinite for dysplasia (IND) patients using formalin-fixed paraffin-embedded (FFPE) BO samples with varying degrees of dysplasia.DesignDNA flow cytometry was performed on 80 FFPE BO samples with high-grade dysplasia (HGD), 38 LGD, 21 IND and 14 negative for dysplasia (ND). Three to four 60-micron thick sections were cut from each tissue block, and the area of interest was manually dissected.ResultsDNA content abnormality was identified in 76 HGD (95%), 8 LGD (21.1%), 2 IND (9.5%) and 0 ND samples. As a diagnostic marker of HGD, the estimated sensitivity and specificity of DNA content abnormality were 95% and 85%, respectively. For patients with DNA content abnormality detected at baseline LGD or IND, the univariate HRs for subsequent detection of HGD or oesophageal adenocarcinoma (OAC) were 7.0 and 20.0, respectively (p =<0.001).ConclusionsThis study demonstrates the promise of DNA flow cytometry using FFPE tissue in the diagnosis and risk stratification of dysplasia in BO. The presence of DNA content abnormality correlates with increasing levels of dysplasia, as 95% of HGD samples showed DNA content abnormality. DNA flow cytometry also identifies a subset of patients with LGD and IND who are at higher risk for subsequent detection of HGD or OAC.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
B. J. M. Zonneveld

Genome size (C-value) was applied anew to investigate the relationships within the genus Hepatica (Ranunculaceae). More than 50 samples representing all species (except H. falconeri), from wild and cultivated material, were investigated. Species of Hepatica turn out to be diploid (), tetraploid ( ), and a possible pentaploid. The somatic nuclear DNA contents (2C-value), as measured by flow cytometry with propidium iodide, were shown to range from 33 to 80 pg. The Asiatic and American species, often considered subspecies of H. nobilis, could be clearly distinguished from European H. nobilis. DNA content confirmed the close relationships in the Asiatic species, and these are here considered as subspecies of H. asiatica. Parents for the allotetraploid species could be suggested based on their nuclear DNA content. Contrary to the increase in genome size suggested earlier for Hepatica, a significant (6%–14%) loss of nuclear DNA in the natural allopolyploids was found.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Wenqin Wang ◽  
Randall A. Kerstetter ◽  
Todd P. Michael

To extensively estimate the DNA content and to provide a basic reference for duckweed genome sequence research, the nuclear DNA content for 115 different accessions of 23 duckweed species was measured by flow cytometry (FCM) stained with propidium iodide as DNA stain. The 1C-value of DNA content in duckweed family varied nearly thirteen-fold, ranging from 150 megabases (Mbp) in Spirodela polyrhiza to 1,881 Mbp in Wolffia arrhiza. There is a continuous increase of DNA content in Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia that parallels a morphological reduction in size. There is a significant intraspecific variation in the genus Lemna. However, no such variation was found in other studied species with multiple accessions of genera Spirodela, Landoltia, Wolffiella, and Wolffia.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 580e-580
Author(s):  
Rodomiro Ortiz ◽  
D.E. Costich ◽  
T.P. Meagher ◽  
N. Vorsa

DNA flow cytometry was used to determine nuclear DNA content in diploid blueberry species, and 3x, 4x, 5x, and 6x ploidy levels. Relative fluorescence intensity of stained nuclei measured by flow cytometry was a function of the number of chromosome sets (X): Y = 3.7X – 2.3 (r2 = 95.1%). DNA flow cytometry should be useful for ploidy level determination in the seedling stage. A significant linear relationship was established between nuclear DNA content and number of chromosomes (x); DNA (pg) = 0.52 x1 (r2 = 99.8%). Based on this equation the haploid genome DNA amount (1C) was calculated as 0.62 ± 0.08 pg, with an approximate haploid genome size of 602 Mbp/1C. The results indicate that conventional polyploid evolution occured in the section Cyanococcus, genus Vaccinium: the increase in DNA was concurrent with increase in chromosome number. DNA content differences among 2x species were correlated with Nei's genetic distance estimates based on 20 isozyme markers. Most of the variation was among species (49%), with 26% between populations within species, and 25% within populations.


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.


2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Teresa Martinu ◽  
Claudia P. Correia ◽  
Andersson M. Figueiredo ◽  
Miguel N. Burnier Jr

Primary intraocular lymphoma is generally considered as a subset of primary CNS lymphoma. This study attempts to show that they may in fact represent distinct entities by comparing their respective proliferation rates using DNA flow cytometry. Four samples of primary intraocular lymphoma and seven samples of primary CNS lymphoma were analyzed, all from paraffin-embedded tissue. All tumors were of the large B-cell type. A normal human tonsil sample was used as a control. Tissue samples were analyzed by DNA flow cytometry, which is a precise and objective method to measure DNA content and cell proliferation of a tumor. S-phase fraction (SPF) and DNA content were measured for each sample. The average SPF for primary intraocular lymphoma was significantly higher than that of primary CNS lymphoma, 23.8 (range: 18.9 to 29.6) versus 15.1 (range: 1.1 to 25.1) respectively. Of the 11 tumors analyzed, 2 brain tumors were aneuploid and 1 eye tumor was peridiploid. All other tumors were diploid. Thus, no significant pattern was detected in the DNA content of the tumors. This lack of clinical significance of tumor aneuploidy is consistent with data reported in the literature. The results of this study indicate that primary intraocular lymphoma is more aggressive and of higher grade than primary CNS lymphoma. The different proliferation rates of intraocular and CNS lymphomas may be explained by either their different spatial location or a distinct genetic composition, the latter reinforcing the hypothesis that the two are fundamentally different entities


Genome ◽  
1995 ◽  
Vol 38 (4) ◽  
pp. 689-695 ◽  
Author(s):  
M. Cerbah ◽  
J. Coulaud ◽  
B. Godelle ◽  
S. Siljak-Yakovlev

Four South American and two European species of Hypochoeris (Asteraceae) were studied using fluorochrome banding, and genome size was determined by flow cytometry, in order to obtain information about microevolution in this genus and about its primary origin. Fluorochrome banding patterns showed GC-rich repeated sequences, particularly around the nucleolar organizer regions. Few differences appeared among the South American species. Nevertheless, determination of nuclear DNA content and base composition revealed significant differences among these species. The phylogenetic position of Hypochoeris robertia, which has the smallest DNA content, is discussed with regard to chromosome evolution in this genus.Key words: Hypochoeris, Asteraceae, fluorochromes, flow cytometry, nucleolar organizer regions, microevolution.


Genome ◽  
2012 ◽  
Vol 55 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Roland Vergilino ◽  
Kaven Dionne ◽  
Christian Nozais ◽  
France Dufresne ◽  
Claude Belzile

The Hyalella azteca (Saussure) complex includes numerous amphipod cryptic species in freshwater habitats in America as revealed by DNA barcoding surveys. Two ecomorphs (small and large) have evolved numerous times in this complex. Few phenotypic criteria have been found to differentiate between the numerous species of this complex. The present study aims to explore genome size differences between some species of the H. azteca complex co-occurring in a Canadian boreal lake using flow cytometry. Nuclear DNA content was estimated for 50 individuals belonging to six COI haplotypes corresponding to four provisional species of the H. azteca complex. Species from the large ecomorph had C-values significantly larger than species from the small ecomorph, whereas slight differences were found among species of the small ecomorph. These differences in genome sizes might be linked to ecological and physiological differences among species of the H. azteca complex.


1990 ◽  
Vol 104 (5) ◽  
pp. 410-416 ◽  
Author(s):  
Adel K. El-Naggar ◽  
J. G. Batsakis ◽  
Mario A. Luna ◽  
Donia McLemore ◽  
R. M. Byers

AbstractFifteen acinic cell carcinomas from an equal number of patients were analysed for their DNA content and proliferative (S-phase) index by flow cytometry from archival tissues. Seven of the carcinomas manifested a diploid DNA content. None of the patients with diploid acinic cell carcinomas died of their carcinomas and none developed metastases in follow-up periods extending for 10 or more years. Four of eight patients with aneuploid acinic cell carcinomas have died because of their malignancies within a 10 year period after the first surgical removal of the carcinoma. Five of the eight patients exhibited metastases. Although the number of cases does not permit strong correlations between histopathological features, abnormalities in DNA content and outcome of patients, it was noted that carcinomas with prominent necrosis, tubulo ductal differentiation and ‘dedifferentiated’ areas displayed more aggressive biological courses.


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