Male haploidy in rotifers: Relative DNA content of nuclei from male and female asplanchna

1976 ◽  
Vol 198 (2) ◽  
pp. 281-285 ◽  
Author(s):  
Philip A. Jones ◽  
John J. Gilbert
2011 ◽  
Vol 39 (No. 2) ◽  
pp. 59-67 ◽  
Author(s):  
I. Doležalová ◽  
A. Lebeda ◽  
M. Dziechciarková ◽  
E. Křístková ◽  
D. Astley ◽  
...  

Fifty one accessions of nineteen Lactuca species, the hybrid L. serriola × L. sativa and the related species Mycelis muralis were evaluated for morphological variability, esterase (EST) polymorphism, Amplified Fragment Length Polymorphism (AFLP) and relative DNA content. Sixteen Lactuca accessions were classified taxonomically on the basis of morphology, isozyme analysis and AFLP. Twenty-eight bands (isoforms) of EST were recorded allowing 82% of accessions to be distinguished. The relative DNA content, measured using flow-cytometry (DAPI staining), ranged from 2.02 pg in L. capensis to 17.96 pg in L. canadensis. The results from AFLP analysis and the relative DNA content measurement corresponded well with recent taxonomic classification of the genus Lactuca.  


1986 ◽  
Vol 72 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Raffaella Uccelli ◽  
Alberto Calugi ◽  
Donato Forte ◽  
Francesco Mauro ◽  
Paolo Polonio-Balbi ◽  
...  

The relative DNA content of cellular samples from 54 patients affected by breast carcinomas and 20 affected by benign breast lesions (including 11 fibroadenomas) was measured by flow cytometry. All normal tissue samples and 17/20 (85%) specimens from benign lesions exhibited a cytometrically diploid DNA distribution, 3/20 (15%) benign lesions an abnormal DNA content, and 35/54 (65%) carcinomas at least one aneuploid cell subpopulation. Furthermore, 9/54 (17%) tumors were characterized by the presence of more than one aneuploid cell subpopulation. The results also indicate that flow cytometry can be used to recognize lymph nodes infiltrated by aneuploid cells. Statistically significant correlations were evidenced between the occurrence of aneuploidy or the ploidy level measured as DNA index and the nodal infiltration status. The percentage of S cells can also be extracted from DNA content distribution histograms. Statistically significant differences (p < 0.01) were also observed for the percentage of S cells between normal tissues (6.2±3.2 SD) and benign lesions (11.1±6.6 SD), normal tissues (6.2 ± 3.2 SD) and aneuploid tumors (19.7 ± 10.3 SD), benign lesions (11.1 ± 6.6 SD) and aneuploid tumors (19.7 ± 10.3 SD), and diploid (7.9 ± 4.0 SD) and aneuploid tumors (19.7 ± 10.3 SD).


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.


Author(s):  
M. V. Skaptsov ◽  
M. A. Krasnoborodkina ◽  
M. G. Kutsev ◽  
S. V. Smirnov ◽  
A. I. Shmakov ◽  
...  

<p>We presented results of variations in the ploidy level and the genome size of the <em>R. acetosa</em> regenerants. These regenerants was obtained by indirect and direct morphogenesis in in vitro culture. Explants were prepared from seedlings on the three-leaf stage of plant development. More than 100 explants were used to stimulate the indirect and direct morphogenesis. Mesophilic explants were cultured on the MS nutrient medium containing auxin to callus proliferation (2 mg/L NAA, 1 mg/L BA). Cultivation of the callus was maintained for 4 weeks followed by an indirect morphogenes. Indirect morphogenesis stimulated on the MS medium with cytokinin and gibberellic acid predominance (0.5 mg/L BA, 0.2 mg/L GA3). Direct stimulate morphogenesis from the apical meristem of seedlings on nutrient media with a predominance of cytokinins (1 mg/L BA, 0.25 mg/L NAA). Rhizogenesis have stimulated by transferring of the regenerants to the ½MS medium supplemented with 0.2 mg/L of NAA. Research of a ploidy level and genome size was performed by flow cytometry used propidium iodide staining with <em>Vicia faba</em> cv “Innovec” (2C=26.90 pg) as internal DNA standard. We calculated the relative DNA content (2C) for <em>R. acetosa</em> equal to 6,98 pg. Cytogenetical analisis showed that the maximum genome size variation recorded for regenerants obtained through the indirect morphogenesis. Variations in the genome size of the regenerants obtained by direct morphogenesis deviates from the control group to 0.30 pg (2С=7.28 pg) and after indirect morphogenesis to 1.04 pg (2С=8.2 pg). Cytogenetical analysis of the regenerated plants showed the presence of different somatic chromosome numbers ranging from 2n = 14 to 2n = 28. The relative DNA content of tetraploid forms was 11.87 pg. In our study was shown, that the most effective method of plant conservation in the <em>in vitro</em> culture is a direct morphogenesis. Analysis of the relative nuclear DNA content and chromosome counts of regenerants obtained by indirect morphogenesis from the callus cultures showed significant variations in the DNA content, as well as the appearance of polyploid forms. Therefore, long-term cultivation of callus cultures increases the probability of genomic aberrations, which reduces the stability of the plant genome.</p>


1982 ◽  
Vol 56 (1) ◽  
pp. 101-111
Author(s):  
M. D. BENNETT ◽  
J. B. SMITH ◽  
J. P. WARD ◽  
R. A. FINCH

The present work used haploid and diploid cells of barley, Hordeum vulgare L. cv. Tuleen 346 (2n = 2x = 14), which has three reciprocal translocations. All seven chromosomes of the haploid set are distinguishable using morphological criteria in Feulgen-stained root-tip squashes seen in the light microscope, as are five of the bivalents at diakinesis. The relative DNA content per bivalent was estimated in pollen mother cells at diakinesis. The results showed that all seven chromosomes or bivalents of Tuleen 346 can be identified using relative DNA content as sole criterion. The absolute and relative volumes of the seven chromosomes were estimated from electron micrographs of serial sections of unsquashed root-tip cells of a haploid. The results show that, using relative chromosome volume as sole criterion, it is highly probable that all seven chromosomes in single unsquashed cells of Tuleen 346 can be correctly identified. Consequently, teats for various non-random spatial arrangements of chromosomes in unsquashed cells of Tuleen 346 using this character to identify the chromosomes should be feasible. There was a very highly significant positive relationship (r&gt;0.99) between relative chromosome volume and mean relative DNA content per chromosome for each cell examined at metaphase of mitosis or meiosis. Thus, some mechanism ensures that the degree of condensation of all seven chromosomes within a cell is usually very similar in Tuleen 346, despite its grossly abnormal karyotype.


2002 ◽  
Vol 22 (7) ◽  
pp. 2220-2228 ◽  
Author(s):  
Tsutomu Shimura ◽  
Masao Inoue ◽  
Masataka Taga ◽  
Kazunori Shiraishi ◽  
Norio Uematsu ◽  
...  

ABSTRACT One difficulty in analyzing the damage response is that the effect of damage itself and that of cellular response are hard to distinguish in irradiated cells. In mouse zygotes, damage can be introduced by irradiated sperm, while damage response can be studied in the unirradiated maternal pronucleus. We have analyzed the p53-dependent damage responses in irradiated-sperm mouse zygotes and found that a p53-responsive reporter was efficiently activated in the female pronucleus. [3H]thymidine labeling experiments indicated that irradiated-sperm zygotes were devoid of G1/S arrest, but pronuclear DNA synthesis was suppressed equally in male and female pronuclei. p53−/− zygotes lacked this suppression, which was corrected by microinjection of glutathione S-transferase-p53 fusion protein. In contrast, p21−/− zygotes exhibited the same level of suppression upon fertilization by irradiated sperm. About a half of the 6-Gy-irradiated-sperm zygotes managed to synthesize a full DNA content by prolonging S phase, while the other half failed to do so. Regardless of the DNA content, all the zygotes cleaved to become two-cell-stage embryos. These results revealed the presence of p53-dependent pronuclear cross talk and a novel function of p53 in the S-phase DNA damage checkpoint of mouse zygotes.


Blood ◽  
1994 ◽  
Vol 83 (6) ◽  
pp. 1493-1498 ◽  
Author(s):  
TP McDonald ◽  
CW Jackson

Abstract C3H mice have higher average ploidy megakaryocytes than all other mouse strains tested, but the mode of inheritance of this anomaly is unknown. Therefore, to clarify the genetics of high ploidy megakaryocytes in C3H mice, we measured megakaryocyte DNA content from both male and female offspring from F1, as well as backcross matings. In all, offspring from seven different matings of mice were studied: (1) C57BL X C57BL (the first strain listed is the male parent in each case), (2) B6C3F1 (offspring from C57BL X C3H mating) X C57BL, (3) C57BL X B6C3F1, (4) C57BL X C3H, (5) C3H X B6C3F1, (6) B6C3F1 X C3H, and (7) C3H X C3H. The polyploid megakaryocyte DNA content distributions of the offspring from these matings show that C3H mice have higher percentages of high ploidy megakaryocytes than did all other mice. Also, male mice had significantly higher percentages of high ploidy (32N and 64N) megakaryocytes than did female mice for all matings, except backcross mating no. 6. The megakaryocyte DNA content for individual offspring of a given backcross appeared to form a single, continuous distribution, rather than segregate into two distinct groups, suggesting that the higher megakaryocyte DNA content of C3H mice is caused by involvement of multiple allelles. This conclusion is further supported by our finding that the frequency of high ploidy megakaryocytes among offspring of the various matings was related to the proportion of C3H genotype contributed by the parents, ie, average megakaryocyte DNA content increased linearly (r2 = .88 for male mice and .84 for female mice. P < .0001) with increasing C3H gene dosage; the correlations for both male and female mice were essentially parallel (slope = 0.08 and 0.09, respectively). In addition, we found an effect of genomic imprinting on megakaryocyte DNA content in backcross offspring. The genetic imprinting was characterized by the female parent having a greater influence on the offspring's megakaryocyte DNA content than the male parent, ie, although the overall genetic makeup was the same, female offspring from backcross no. 6 (in which the female was C3H) had higher average megakaryocyte ploidy values than those from backcross no. 5 (in which the female was B6C3F1


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