scholarly journals Cytogenetic studies in three diploid species of Andropogon (Andropogoneae), section Leptopogon

Rodriguésia ◽  
2019 ◽  
Vol 70 ◽  
Author(s):  
María I. Hidalgo ◽  
Eduardo J. Greizerstein ◽  
Guillermo A. Norrmann
Keyword(s):  
Dna Content ◽  
Nuclear Dna ◽  
Secondary Constriction ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Diploid Species ◽  
Nuclear Dna Content ◽  
Nucleolar Organizer ◽  
Relevant Information ◽  
Fluorochrome Banding

Abstract Karyotypes can provide a relevant information about relationships and evolutionary origin among species of the Andropogon genus. This paper presents the karyotype, C+ and DAPI/CMA3 banding and DNA content of three diploid (2n=20) species belonging to section Leptopogon: A. selloanus, A. macrothrix and A. gyrans. Karyotypes of the three diploid species are symmetrical. We propose a karyotype formulae (18m + 2sm) for each of them. The three species show a pair of metacentric chromosomes with a terminal secondary constriction on short arms. Fluorochrome banding revealed different constitutive heterochromatin patterns and CMA3+/DAPI¬ terminal bands related to the nucleolar organizer region in each species. Nuclear DNA content was estimated by flow cytometry ranged from 2.22 to 2.61 pg. FISH technique revealed that these three species have two 45S rDNA loci at the distal ends of the short arms of two metacentric chromosomes. We compare the genomes of the diploids A. selloanus, A. macrothrix and A. gyrans, and the triploid A. ternatus using GISH. These technique allowed us to confirm the hypotheses that the A. selloanus, A. macrothrix and A. gyrans constitute a homogeneous group that share a common S genome that comprises just one of the genomes in the triploid A. ternatus.

Genome size, fluorochrome banding, and karyotype evolution in some Hypochoeris species

Genome ◽  
1995 ◽  
Vol 38 (4) ◽  
pp. 689-695 ◽  
Author(s):  
M. Cerbah ◽  
J. Coulaud ◽  
B. Godelle ◽  
S. Siljak-Yakovlev
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Nucleolar Organizer ◽  
Phylogenetic Position ◽  
Nucleolar Organizer Regions ◽  
Fluorochrome Banding ◽  
South American

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.

scholarly journals Relationship of AgNOR counts and nuclear DNA content to survival in patients with parathyroid carcinoma

2004 ◽  
Vol 11 (3) ◽  
pp. 563-569 ◽  
Author(s):  
F Lumachi ◽  
M Ermani ◽  
F Marino ◽  
A Poletti ◽  
SMM Basso ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Parathyroid Carcinoma ◽  
Nuclear Dna ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nuclear Dna Content ◽  
Nucleolar Organizer ◽  
Dna Flow Cytometry ◽  
Dna Index ◽  
Tissue Sections

The aim of this study was to evaluate the usefulness of DNA flow cytometry to determine tumor nuclear DNA index (DI), and nucleolar organizer region protein counts visualized by the argyrophil (AgNOR) technique, in confirming diagnosis and predicting clinical outcome of patients with parathyroid carcinoma (PC). We reviewed paraffin-embedded tissue sections, from 15 patients (median age 63 years, range 30–68 years) with PC who died of the disease, which were randomly compared with tissue sections from 15 age- and sex-matched patients with parathyroid adenoma (PA). The proliferative activity in parathyroid tumours as detected by DI and AgNOR counts was evaluated in all specimens. Both DI (1.37 ± 0.33 vs 1.0 ± 0.1) and AgNOR (3.01 ± 0.31 vs 1.54 ± 0.35) counts were higher (P < 0.001) (Student’s t-test) in patients with PC than in those with PA. Diploid (DI = 1), aneuploid (DI>1) and hypoploid (DI<1) neoplasms were found in 11 (PC = 4, PA = 7), 14 (PC = 11, PA = 3) and five (PC = 0, PA = 5) patients respectively. The average postoperative survival in patients with PC was 46.9 ± 37.4 months (range 21–146 months). The survivals of patients with aneuploid (n = 11) and diploid (n = 4) PC were 74.0 ± 58.1 and 34.1 ± 18.4 months (P=0.21) respectively. There was a significant relationship between DI and AgNOR counts (R=0.69, P < 0.01), but no correlation was found between survival and both DI (Rho = 0.17, P = 0.55) and AgNOR counts (Rho = 0.26, P = 0.35). Moreover, there was no correlation (P = NS) between the main preoperative biochemical parameters and survival. In conclusion, DI and AgNOR are useful in confirming the diagnosis of PC, but they are of little value in predicting the clinical outcome of patients with PC.

scholarly journals BOTH NUCLEOLAR ORGANIZERS ARE REPLICATED IN DIPTERAN POLYPLOID TISSUES: A STUDY AT THE LEVEL OF INDIVIDUAL NUCLEI

Genetics ◽  
1985 ◽  
Vol 111 (2) ◽  
pp. 325-336
Author(s):  
Esther J Belikoff ◽  
Kathy Beckingham
Keyword(s):  
Salivary Gland ◽  
Nurse Cell ◽  
Nuclear Dna ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Single Pair ◽  
Cell Nuclei ◽  
Calliphora Erythrocephala ◽  
Nontranscribed Spacer

ABSTRACT Working with the Dipteran Calliphora erythrocephala, we have tested the hypothesis that only one nucleolar organizer region (NO) is replicated during polyploidization. NO replication was examined in two very different highly polyploid nuclear types: salivary gland nuclei and nurse cell nuclei. Two strains of the organism containing NO regions with highly diagnostic nontranscribed spacer (NTS) polymorphisms were prepared and reciprocal single pair-matings between members of the strains were performed. The representation of the two distinguishable NOs in diploid and polyploid DNAs of individual F1 progeny from each cross was then examined. DNA from a total polyploid nuclear DNA preparation and from individual polyploid nuclei of both tissue types was analyzed. Our results show conclusively that both genomic NOs are replicated in individual polyploid nuclei of both types. Further, evidence for variation in the relative replication of cistrons from the two NOs by individual nuclei was obtained. The cistron types present in the NOs of both strains showed differential replication upon polyploidization. In general, the patterns of differential cistron replication seen in salivary gland and nurse cell nuclei were similar.

Genome size and genome evolution in diploid Triticeae species

Genome ◽  
2007 ◽  
Vol 50 (11) ◽  
pp. 1029-1037 ◽  
Author(s):  
T. Eilam ◽  
Y. Anikster ◽  
E. Millet ◽  
J. Manisterski ◽  
O. Sagi-Assif ◽  
...  
Keyword(s):  
Genome Size ◽  
Intraspecific Variation ◽  
Dna Content ◽  
Nuclear Dna ◽  
Diploid Species ◽  
Nuclear Dna Content ◽  
Dna Amount ◽  
Nuclear Dna Amount ◽  
Speciation Event ◽  
Close Temporal Proximity

One of the intriguing issues concerning the dynamics of plant genomes is the occurrence of intraspecific variation in nuclear DNA amount. The aim of this work was to assess the ranges of intraspecific, interspecific, and intergeneric variation in nuclear DNA content of diploid species of the tribe Triticeae (Poaceae) and to examine the relation between life form or habitat and genome size. Altogether, 438 plants representing 272 lines that belong to 22 species were analyzed. Nuclear DNA content was estimated by flow cytometry. Very small intraspecific variation in DNA amount was found between lines of Triticeae diploid species collected from different habitats or between different morphs. In contrast to the constancy in nuclear DNA amount at the intraspecific level, there are significant differences in genome size between the various diploid species. Within the genus Aegilops , the 1C DNA amount ranged from 4.84 pg in A. caudata to 7.52 pg in A. sharonensis; among genera, the 1C DNA amount ranged from 4.18 pg in Heteranthelium piliferum to 9.45 pg in Secale montanum . No evidence was found for a smaller genome size in annual, self-pollinating species relative to perennial, cross-pollinating ones. Diploids that grow in the southern part of the group’s distribution have larger genomes than those growing in other parts of the distribution. The contrast between the low variation at the intraspecific level and the high variation at the interspecific one suggests that changes in genome size originated in close temporal proximity to the speciation event, i.e., before, during, or immediately after it. The possible effects of sudden changes in genome size on speciation processes are discussed.

Karyotype, meiotic behavior and pollen features of Senna occidentalis

Biologia ◽  
2010 ◽  
Vol 65 (5) ◽  
Author(s):  
Kátia Ferreira ◽  
Giovana Torres ◽  
Saulo Sousa ◽  
Aparecida Santos
Keyword(s):  
Chromosome Pair ◽  
Pollen Morphology ◽  
Secondary Constriction ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Pollen Grains ◽  
Nucleolar Organizer ◽  
Mitotic Metaphase ◽  
Meiotic Behavior ◽  
Mitotic Metaphase Chromosome

AbstractMeiotic behavior, pollen morphology, interphasic nucleus pattern and karyotype description for Senna occidentalis (Caesalpinioideae — Fabaceae) are presented. The species had non-reticulate interphasic nucleus and homogeneous chromosome condensing with minute distal late-condensing portions in prometaphase. In mitotic metaphase, chromosome number was 2n = 28 (9 m + 5 sm), with secondary constriction in one chromosome pair. Detection of four nucleoli indicated existence of two chromosome pairs bearing Nucleolar Organizer Region (NOR). Meiotic behavior was regular, with high meiotic index (95%). Pollen grains, classified as polar/spheroidal, presented 90% viability.

scholarly journals Determining Ploidy Level and Nuclear DNA Content in Rubus by Flow Cytometry

2002 ◽  
Vol 127 (5) ◽  
pp. 767-775 ◽  
Author(s):  
Rengong Meng ◽  
Chad Finn
Keyword(s):  
Flow Cytometry ◽  
Pacific Northwest ◽  
Ploidy Level ◽  
Dna Content ◽  
Chromosome Numbers ◽  
Nuclear Dna ◽  
Diploid Species ◽  
Nuclear Dna Content ◽  
Dna Flow Cytometry ◽  
Ploidy Levels

Nuclear DNA flow cytometry was used to differentiate ploidy level and determine nuclear DNA content in Rubus. Nuclei suspensions were prepared from leaf discs of young leaves following published protocols with modifications. DNA was stained with propidium iodide. Measurement of fluorescence of 40 genotypes, whose published ploidy ranged from diploid to dodecaploid, indicated that fluorescence increased with an increase in chromosome number. Ploidy level accounted for 99% of the variation in fluorescence intensity (r2 = 0.99) and variation among ploidy levels was much higher than within ploidy levels. This protocol was used successfully for genotypes representing eight different Rubus subgenera. Rubus ursinus Cham. and Schldl., a native blackberry species in the Pacific Northwest, which has been reported to have 6x, 8x, 9x, 10x, 11x, and 12x forms, was extensively tested. Genotypes of R. ursinus were predominantly 12x, but 6x, 7x, 8x, 9x, 11x, and 13x forms were found as well. Attempts to confirm the 13x estimates with manual counts were unsuccessful. Ploidy level of 103 genotypes in the USDA-ARS breeding program was determined by flow cytometry. Flow cytometry confirmed that genotypes from crosses among 7x and 4x parents had chromosome numbers that must be the result of nonreduced gametes. This technique was effective in differentiating chromosome numbers differing by 1x, but was not able to differentiate aneuploids. Nuclear DNA contents of 21 diploid Rubus species from five subgenera were determined by flow cytometry. Idaeobatus, Chamaebatus, and Anaplobatus were significantly lower in DNA content than those of Rubus and Cylactis. In the Rubus subgenus, R. hispidus and R. canadensis had the lowest DNA content and R. sanctus had the highest DNA content, 0.59 and 0.75 pg, respectively. Idaeobatus had greater variation in DNA content among diploid species than the Rubus subgenus, with the highest being from R. ellipticus (0.69 pg) and lowest from R. illecebrosus (0.47 pg).

scholarly journals Nuclear DNA Content, Base Composition, and Cytogenetic Characterization of Christia obcordata

2013 ◽  
Vol 138 (3) ◽  
pp. 205-209 ◽  
Author(s):  
Hamidou F. Sakhanokho ◽  
Nurul Islam-Faridi
Keyword(s):  
Ribosomal Rna ◽  
Dna Content ◽  
Nuclear Dna ◽  
Organizer Region ◽  
Nuclear Dna Content ◽  
5S Rdna ◽  
Gene Families ◽  
Root Tip ◽  
Ribosomal Rna Gene ◽  
A Genome

Christia obcordata is an intriguing small-sized house plant with unusual and attractive features such as its striped leaves. Because very little is known about the plant, we conducted an investigation of its genome and chromosomes. The number of chromosomes was determined using a protoplast technique to prepare root tip chromosome spread and was found to be 2n = 2x = 20. Flow cytometry was used to determine nuclear DNA content (1C = 0.65 pg = 634.4 Mb) for C. obcordata and AT/GC composition was shown to be AT% = 62.8% ± 0.0% and GC% = 37.2% ± 0.0%. Finally, fluorescent in situ hybridization was used to locate ribosomal RNA gene families in C. obcordata. Ribosomal RNA gene families, viz. 18S-28S and 5S rDNA, are unique cytomolecular landmarks that provide valuable information about the evolutionary organization of a genome. We have identified one locus each of 18S-28S and 5S rDNA. The 18S-28S rDNA is located in the subterminal position on the secondary constriction region [also known as the nucleolus organizer region (NOR)] and the 5S rDNA is located interstitially close to a centromeric position. The basic information gathered in this study on C. obcordata will be helpful in understanding the genetics of this species.

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