ACTIVITY AND RELATIVE MOBILITY OF PEROXIDASE AND ESTERASE ISOZYMES OF FLAX (LINUM USITATISSIMUM) GENOTROPHS. II. F1 HYBRIDS AND NUCLEAR DNA REVERSION TYPES

The effects of growth of one genotype of flax in soil supplemented by either nitrogen, phosphorous and potassium (NPK) or nitrogen and potassium (NK) on its progeny produced by several generations of complete selfing were studied. The two types of progeny produced, genotroph L, induced by NPK and genotroph S induced by NK, and their F1 reciprocal hybrids were examined. L and S differed in plant weight and in the activities and relative mobilities of their corresponding anionic peroxidase and esterase isozymes. No reciprocal differences were detected and the mean F1 values for all characteristics were intermediate between the parents, with the exception of the peroxidase isozyme relative mobilities which displayed dominance of parent L. The genotrophs were known to exhibit a 16% difference in nuclear DNA content which could be reverted to 0%, without altering the genotroph fresh weight difference, by growing the genotrophs in lower than normal temperatures. Examination of the peroxidase and esterase isozymes of nDNA reverted genotrophs showed that, with one possible exception, there was no accompanying reversion of the activities and relative mobilities of the peroxidase or esterase isozymes.

Download Full-text

Nuclear DNA content and minimum generation time in herbaceous plants

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1972.0042 ◽

1972 ◽

Vol 181 (1063) ◽

pp. 109-135 ◽

Cited By ~ 406

Keyword(s):

Cell Cycle ◽

Dna Content ◽

Cycle Time ◽

Generation Time ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Annual Species ◽

Cell Cycle Time ◽

Developmental Processes ◽

The Mean

Many components of cell and nuclear size and mass are correlated with nuclear DNA content in plants, as also are the durations and rates of such developmental processes as mitosis and meiosis. It is suggested that the multiple effects of the mass of nuclear DNA which affect all cells and apply throughout the life of the plant can together determine the minimum generation time for each species. The durations of mitosis and of meiosis are both positively correlated with nuclear DNA content and, therefore, species with a short minimum generation time might be expected to have a shorter mean cell cycle time and mean meiotic duration, and a lower mean nuclear DNA content, than species with a long mean minimum generation time. In tests of this hypothesis, using data collated from the literature, it is shown that the mean cell cycle time and the mean meiotic duration in annual species is significantly shorter than in perennial species. Furthermore, the mean nuclear DNA content of annual species is significantly lower than for perennial species both in dicotyledons and monocotyledons. Ephemeral species have a significantly lower mean nuclear DNA content than annual species. Among perennial monocotyledons the mean nuclear DNA content of species which can complete a life cycle within one year (facultative perennials) is significantly lower than the mean nuclear DNA content of those which cannot (obligate perennials). However, the mean nuclear DNA content of facultative perennials does not differ significantly from the mean for annual species. It is suggested that the effects of nuclear DNA content on the duration of developmental processes are most obvious during its determinant stages, and that the largest effects of nuclear DNA mass are expressed at times when development is slowest, for instance, during meiosis or at low temperature. It has been suggested that DNA influences development in two ways, directly through its informational content, and indirectly by the physical-mechanical effects of its mass. The term 'nucleotype' is used to describe those conditions of the nucleus which effect the phenotype independently of the informational content of the DNA. It is suggested that cell cycle time, meiotic duration, and minimum generation time are determined by the nucleotype. In addition, it may be that satellite DNA is significant in its nucleotypic effects on developmental processes.

Download Full-text

Ex vivo zidovudine (AZT) treatment of CD34+ bone marrow progenitors causes decreased steady state mitochondrial DNA (mtDNA) and increased lactate production

Human & Experimental Toxicology ◽

10.1191/0960327104ht437oa ◽

2004 ◽

Vol 23 (4) ◽

pp. 173-185 ◽

Cited By ~ 12

Author(s):

L D Lewis ◽

S Amin ◽

C I Civin ◽

P S Lietman

Keyword(s):

Bone Marrow ◽

Mitochondrial Dna ◽

Steady State ◽

Nuclear Dna ◽

Ex Vivo ◽

Lactate Production ◽

Nuclear Dna Content ◽

Content Ratio ◽

The Mean

Haematopoietic suppression is one of the dose-limiting side effects of chronic zidovudine (AZT) therapy. We tested the hypothesis that AZT would reduce mitochondrial DNA (mtDNA) content in haematopoietic progenitors causing impaired haematopoiesis and mitochondrial dysfunction. We studied the effects of AZT 0 / 50 M in vitro, on normal human CD34 / haematopoietic progenitor cells cultured ex vivo for up to 12 days. The mean AZT IC50 for granulocyte (phenotype CD15 / /CD14 /) and erythroid (phenotype glycophorin / /CD45 /) cell proliferation was 2.5 M (SD9 / 0.7) and 0.023 M (SD9 / 0.005), respectively. In myeloid-rich cell cultures, the mean lactate content of the media, compared to untreated controls, increased by 86% (SD9 / 23) at 10 M AZT and in erythroid-rich cultures it increased by 134% (SD9 / 24) in the presence of 0.5 M AZT. In myeloid-rich cultures the AZT IC50 for the reduction in the mitochondrial/nuclear DNA content ratio was 5.6 M, whereas in erythroid rich cultures this AZT IC50 was B / 0.0005 M. AZT produced concentration-dependent inhibition of CD34 / progenitor proliferation into both myeloid and erythroid lineages; erythropoiesis was more sensitive than myelopoiesis. Concurrently, AZT reduced steady state mtDNA content, while increasing lactate production. These findings support the hypothesis that mtDNA is one of the intracellular targets involved in the pathogenesis of AZT-associated bone marrow progenitor cell toxicity.

Download Full-text

Nuclear DNA content in F1 hybrids of maize

Heredity ◽

10.1038/hdy.1993.42 ◽

1993 ◽

Vol 70 (3) ◽

pp. 294-300 ◽

Cited By ~ 48

Author(s):

A Lane Rayburn ◽

D P Biradar ◽

D G Bullock ◽

L M McMurphy

Keyword(s):

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

F1 Hybrids

Download Full-text

Development and Characteristics of Interspecific Hybrids between Brassica oleracea L. and B. napus L.

Agronomy ◽

10.3390/agronomy10091339 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1339

Author(s):

Piotr Kamiński ◽

Agnieszka Marasek-Ciolakowska ◽

Małgorzata Podwyszyńska ◽

Michał Starzycki ◽

Elżbieta Starzycka-Korbas ◽

...

Keyword(s):

Dna Content ◽

Interspecific Hybrids ◽

Nuclear Dna ◽

Morphological Characteristics ◽

Nuclear Dna Content ◽

F1 Hybrids ◽

Male Sterile ◽

Dna Contents ◽

F2 Generation ◽

Head Cabbage

Interspecific hybridization between B. oleracea inbred lines of head cabbage, Brussels sprouts, kale and B. taurica and inbred lines of rapeseed (B. napus L.) were performed aiming at the development of the new sources of genetic variability of vegetable Brassicas. Using conventional crossings and the embryo-rescue techniques the following interspecific hybrids were developed: 11 genotypes of F1 generation, 18 genotypes of F2 and F1 × F2 generations (produced after self- and cross-pollination of interspecific F1 hybrids), 10 plants of the BC1 generation (resulted from crossing head cabbage cytoplasmic male-sterile lines with interspecific hybrids of the F2 and F1 generations) and 8 plants of BC1 × (F1 × F2). No viable seeds of the BC2 generation (B. oleracea) were obtained due to the strong incompatibility and high mortality of embryos. The morphological characteristics during the vegetative and generative stages, pollen characteristics, seed development and propagation, nuclear DNA contents and genome compositions of interspecific hybrids were analyzed. All the interspecific F1 hybrids were male-fertile with a majority of undeveloped and malformed pollen grains. They showed intermediate values for morphological traits and nuclear DNA contents and had nearly triploid chromosomal numbers (27 to 29) compared with parental lines. The F2 generation had a doubled nuclear DNA content, with 52 and 56 chromosomes, indicating their allohexaploid nature. F2 hybrids were characterized by a high heterosis of morphological characteristics, viable pollen and good seed development. F1 × F2 hybrids were male-fertile with a diversified DNA content and intermediate pollen viability. BC1 plants were male-sterile with an intermediate nuclear DNA content between the F2 and head cabbage, having 28 to 38 chromosomes. Plants of the BC1 × (F1 × F2) generation were in majority male-fertile with 38–46 chromosomes, high seed set, high heterosis and intermediate values for morphological traits. The obtained interspecific hybrids are valuable as new germplasm for improving Brassica-breeding programs.

Download Full-text

Genome size variation in Corchorus olitorius (Malvaceae s.l.) and its correlation with elevation and phenotypic traits

Genome ◽

10.1139/g11-021 ◽

2011 ◽

Vol 54 (7) ◽

pp. 575-585 ◽

Cited By ~ 19

Author(s):

Solomon Benor ◽

Jörg Fuchs ◽

Frank R. Blattner

Keyword(s):

Genome Size ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Phenotypic Traits ◽

Corchorus Olitorius ◽

Genome Size Variation ◽

Crop Species ◽

Plant Materials ◽

The Mean

In this study, we report genome size variations in Corchorus olitorius L. (Malvaceae s.l.), a crop species known for its morphological plasticity and broad geographical distribution, and Corchorus capsularis L., the second widely cultivated species in the genus. Flow cytometric analyses were conducted with several tissues and nuclei isolation buffers using 69 accessions of C. olitorius and 4 accessions of C. capsularis, representing different habitats and geographical origins. The mean 2C nuclear DNA content (± SD) of C. olitorius was estimated to be 0.918 ± 0.011 pg, with a minimum of 0.882 ± 0.004 pg, and a maximum of 0.942 ± 0.004 pg. All studied plant materials were found to be diploid with 2n = 14. The genome size is negatively correlated with days to flowering (r = –0.29, p < 0.05) and positively with seed surface area (r = 0.38, p < 0.05). Moreover, a statistically significant positive correlation was detected between genome size and growing elevation (r = 0.59, p < 0.001) in wild populations. The mean 2C nuclear DNA content of C. capsularis was estimated to be 0.802 ± 0.008 pg. In comparison to other economically important crop species, the genome sizes of C. olitorius and C. capsularis are much smaller, and therewith closer to that of rice. The relatively small genome sizes will be of general advantage for any efforts into genomics or sequencing approaches of these species.

Download Full-text

IMAGE ANALYSIS OF CHROMATIN IN CELLS OF PREIMPLANTATION MOUSE EMBRYOS

The Journal of Cell Biology ◽

10.1083/jcb.63.1.227 ◽

1974 ◽

Vol 63 (1) ◽

pp. 227-233 ◽

Cited By ~ 13

Author(s):

Wojciech Sawicki ◽

Jan Rowínski ◽

Jan Abramczuk

Keyword(s):

Cell Cycle ◽

Image Analysis ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Mouse Embryos ◽

Stage Of Development ◽

Preimplantation Mouse Embryos ◽

Preimplantation Mouse ◽

The Mean

Mouse two-celled embryos and blastulae were Feulgen stained and the DNA content of their nuclei was measured with an integrating microdensitometer. The cells considered on the basis of their nuclear DNA content to be in G1, S, and G2 phases of the cell cycle were selected and their total chromatin area and chromatin areas at different gray levels were measured by the image analyzing computer, Quantimet. The measurements were aimed at quantitation of several features of the chromatin morphology of cells in different functional states. The total area of chromatin was found to increase, and the mean density of chromatin to decrease, from the G1 to the G2 phase of the cell cycle in both two-celled embryos and blastulae. The area of chromatin decreased, and the mean density of chromatin increased, as embryos developed from two-celled to blastula stage. It was concluded that nuclear morphology in preimplantation mouse embryos depends on both the phase of the cell cycle and the stage of development. The method of image analysis described was found to be useful for quantitation of changes in chromatin morphology.

Download Full-text

Impact d'un traitement par le cycloheximide sur la reprise du cycle et sur les teneurs en protéines du bourgeon cotylédonaire du Pois réactivé par décapitation

Canadian Journal of Botany ◽

10.1139/b90-053 ◽

1990 ◽

Vol 68 (2) ◽

pp. 420-427 ◽

Cited By ~ 3

Author(s):

Arlette Nougarède ◽

Pierre Rondet ◽

Pierre Landré ◽

Robert Saint-Côme

Keyword(s):

Protein Content ◽

Mitotic Activity ◽

Dna Content ◽

Nuclear Protein ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

S Phase ◽

Cytoplasmic Protein ◽

The Mean ◽

Low Amplitude

Following ablation of the main stem (decapitation), the mean nuclear protein content of the Pisum cotyledonary bud apical cells increased 35% as early as the 6th hour, just when a massive entry into the S phase was registered, and reached a maximum, with a 157% increase, at the 39th hour, when the mitotic activity was also at its highest. The ratio nuclear protein/nuclear DNA content was then multiplied by 1.8 in comparison with the ratio observed in the G0–1 noncycling nuclei of the inhibited cotyledonary bud. In the bud treated with cycloheximide, the mean nuclear protein content slowly increased following decapitation, but remained greatly inferior to that of the controls. A slight entry into the S phase was noticed at the 24th hour and the mean nuclear protein content, then maximal, increased 32% in comparison with the inhibited buds. In the control buds, the mean protoplasmic proteins content increased 116% at the 39th hour (maximal value), whereas it increased only 25% in the treated buds. Following treatment with cycloheximide, the entry into the S phase was postponed and of low amplitude. However, the recycling nuclei were able to divide. An increase in the mean nuclear and cytoplasmic protein content was a prerequisite if the entry into the S phase of G0–1, nuclei was not to be postponed.

Download Full-text

Pattern of DNA increase in macronuclear anlagen of Tetrahymena

Journal of Cell Science ◽

10.1242/jcs.83.1.155 ◽

1986 ◽

Vol 83 (1) ◽

pp. 155-164

Author(s):

J. Roth ◽

G. Cleffmann

Keyword(s):

Cell Cycle ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

S Phase ◽

The Mean

By combining cytophotometry with autoradiography, five stages of macronuclear anlagen can be discriminated by their DNA content until the end of the first cell cycle after conjugation in Tetrahymena. DNA increases from 2C to about 32C. Each S-phase is followed by a non-synthetic period. Comparing the mean nuclear DNA content after and before each S-phase revealed that 16C anlagen contain significantly less DNA than twice the amount of 8C anlagen. This is unlike the situation in other S-phases during which the amount of DNA is precisely doubled. In the second cell cycle after conjugation some of the cells increase their macronuclear G2 DNA content beyond the 64C stage, while the majority show a mean G2 content of about 64C.

Download Full-text