scholarly journals Estimation of Genome Size (C-Value) in Iridaceae by Cytophotometry

1984 ◽  
Vol 71 (1) ◽  
pp. 176 ◽  
Author(s):  
Peter Goldblatt ◽  
Virginia Walbot ◽  
Elizabeth A. Zimmer
Keyword(s):  
1994 ◽  
Vol 42 (11) ◽  
pp. 1413-1416 ◽  
Author(s):  
S L Erlandsen ◽  
E M Rasch

We investigated direct measurement of the DNA content of the parasitic intestinal flagellate Giardia lamblia through quantitation by Feulgen microspectrophotometry and also by visualization of Feulgen-stained DNA chromosomes within dividing cells by laser scanning confocal microscopy. Individual trophozoites of Giardia (binucleate) contained 0.144 +/- 0.018 pg of DNA/cell or 0.072 pg DNA/nucleus. Giardia lamblia cysts (quadranucleate) contained 0.313 +/- 0.003 pg DNA or 0.078 pg DNA/nucleus. The genome size (C) value per nucleus ranged between 6.5-7.1 x 10(7) BP for trophozoites and cysts, respectively. Confocal microscopic examination of Giardia trophozoites undergoing binary fission revealed five chromosome-like bodies within each nucleus. Further information about genome size and DNA content within different Giardia species may help to clarify the pivotal role of these primitive eukaryotic cells in evolutionary development.


2009 ◽  
Vol 23 (30) ◽  
pp. 3563-3580 ◽  
Author(s):  
DIRSON JIAN LI ◽  
SHENGLI ZHANG

We find that the global relationships among species should be of circular phylogeny, which is quite different from common sense based on phylogenetic trees. A domain can be defined by a distinct phylogenetic circle, which is a global and stable characteristic of the living system. The mechanism in genome size evolution has been clarified; hence the main component questions on C-value enigma can be explained. We find the intrinsic relationship between genome size evolution and protein length evolution; that is the genome size and non-coding DNA ratio can be calculated based on protein length distributions.


2003 ◽  
Vol 41 (1) ◽  
pp. 63-69 ◽  
Author(s):  
B. G. Murray ◽  
I. E. Weir ◽  
A. R. Ferguson ◽  
P. J. De Lange

2002 ◽  
Vol 50 (6) ◽  
pp. 735-749 ◽  
Author(s):  
David C. Hardie ◽  
T. Ryan Gregory ◽  
Paul D.N. Hebert

The study of genome size variation is important from a number of practical and theoretical perspectives. For example, the long-standing “C-value enigma” relating to the more than 200,000-fold range in eukaryotic genome sizes is best studied from a broad comparative standpoint. Genome size data are also required in detailed analyses of genome structure and evolution. The choice of future genome sequencing projects will be dependent on knowledge regarding the sizes of genomes to be sequenced, and so on. To date, genome size data have been acquired primarily by Feulgen microdensitometry or flow cytometry. Each has several advantages but also important limitations. In this review, we provide a practical guide to the new technique of Feulgen image analysis densitometry. The review is designed for those interested in genome size measurements but not extensively experienced in histochemistry, densitometry, or microscopy. Therefore, relevant historical and technical background information is included. For easy reference, we provide recipes for required reagents, guidelines for cell staining, and a checklist of steps for successful image analysis. We hope that the accuracy, rapidity, and cost-effectiveness of Feulgen image analysis demonstrated here will stimulate further surveys of genome sizes in a variety of taxa.


2011 ◽  
Vol 59 (2) ◽  
pp. 149 ◽  
Author(s):  
Isabella Santiago Abreu ◽  
Carlos Roberto Carvalho ◽  
Guilherme Mendes Almeida Carvalho ◽  
Sérgio Yoshimitsu Motoike

The oleaginous species Acrocomia aculeata produces high-quality oil and is considered a potential plant for sustainable production of food and biodiesel. In spite of its economical, social and environmental importance, few data concerning the genome size and chromosomal characterisation of this crop have been reported. In order to contribute to basic genetic knowledge on A. aculeata, this work aimed to assemble the first karyogram and to determine genome size and base composition of this species. Concerning the cytogenetic approach, we developed a protocol based on root tips treatment with an anti-mitotic agent, followed by enzymatic maceration and slide preparation by the air-drying technique. This method provided well resolved metaphasic chromosomes, which are important for an accurate and informative cytogenetical characterisation. A chromosome number of 2n = 30 was observed. Content of 2C DNA and base composition were estimated by flow cytometry of G0/G1 nuclei stained with propidium iodide and 4′,6-diamidino-2-phenylindole, respectively. The mean 2C-value and base composition corresponded to 2C = 5.81 pg and AT = 58.3%. These new data support basic genetic knowledge on A. aculeata, relevant for its conservation, diversity studies and consequent development of breeding programs, which may foment the biofuel production in the world.


Genome ◽  
1990 ◽  
Vol 33 (4) ◽  
pp. 604-610 ◽  
Author(s):  
Ann Kenton ◽  
Andrew Drakeford

Karyotype morphology and nuclear DNA content are compared in species of Tradescantia section Cymbispatha from North and South America. Comparison of DNA amounts confirms the polyploid ancestry previously suggested for several cytotypes and shows that basic genome size has been unaffected by the Robertsonian fusions constituting a major evolutionary change in this group. The 2C-values of Mexican tetraploids are double those of their Central American diploid relative Tradescantia gracillima. The 2C-value of the South American tetraploid T. cymbispatha is comparatively lower as a result of a reduction in the size of some chromosomes. This reduction is most likely to have been achieved by Robertsonian fusions in a hybrid whose parental chromosome sets differed in size. The results provide evidence for selection of ancestral diploids with low C-value as mechanism for reduction of genome size in polyploids.Key words: Tradescantia, genome size, polyploidy, Robertsonian fusion, DNA reduction.


Genome ◽  
2002 ◽  
Vol 45 (5) ◽  
pp. 833-838 ◽  
Author(s):  
T Ryan Gregory

Although unrelated to any intuitive notions of organismal complexity, haploid genome sizes (C values) are correlated with a variety of cellular and organismal parameters in different taxa. In some cases, these relationships are universal — notably, genome size correlates positively with cell size in each of the vertebrate classes. Other relationships are apparently relevant only in particular groups. For example, although genome size is inversely correlated with metabolic rate in both mammals and birds, no such relationship is found in amphibians. More recently, it has been suggested that developmental rate and (or) longevity are related to genome size in birds. In the present study, a large dataset was used to examine possible relationships between genome size and various developmental parameters in both birds and mammals. In neither group does development appear to be of relevance to genome size evolution (except perhaps indirectly in birds through the intermediation of body size and (or) within the rodents), a situation very different from that found in amphibians. These findings make it clear that genome size evolution cannot be understood without reference to the particular biology of the organisms under study.Key words: body size, C-value enigma, C-value paradox, fledging, gestation, growth, incubation, lactation, metabolism.


1983 ◽  
Vol 25 (6) ◽  
pp. 554-560 ◽  
Author(s):  
J. Greilhuber ◽  
M. Volleth ◽  
J. Loidl

A direct Feulgen-cytophotometric comparison of the genomic DNA content (C value) was performed between the liliaceous plant species Allium cepa and a number of animal species to reassess the genome size ratios between plants and animals. These appeared unduely ambiguous as a consequence of divergent picogram estimates in several animal reference species. Taking 1C = 16.75 pg for Allium cepa, the estimates were (1C value in picograms): man, 3.11; Indian muntjak CCL 157 cell line, 2.68; domestic pig, 2.79; Chinese hamster, 2.66; CHO cell line, 2.73; laboratory rat, 2.65; mouse, 3.04; rat kangaroo Pt-K2 cell line, 4.21; fowl, 1.16; and the green toad, 4.30. These values are consistent with a number of independent absolute and relative DNA content determinations reported for animals, and therefore define a coherent set of animal and plant reference values for genome size determinations.


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