Late DNA replication pattern in sex chromosomes of Melandrium.

  title={Late DNA replication pattern in sex chromosomes of Melandrium.},
  author={H. C. Choudhuri},
  journal={Canadian journal of genetics and cytology. Journal canadien de genetique et de cytologie},
  volume={11 1},
  • H. C. Choudhuri
  • Published 1969
  • Biology, Medicine
  • Canadian journal of genetics and cytology. Journal canadien de genetique et de cytologie
DNA replication patterns in somatic cells of female and male Meladrium album were studied with autoradiographic methods. The S-period and the average generation time have been estimated to be 5.7 and 15.5 hours respectively. The heterochromatin observed in interphase nuclei may represent the late replicating and presumably inactivated sex chromosome.One arm of one X chromosome is late replicating in females. In the Y chromosome a region near the centromere replicates late in the S-period. The… Expand
Replication patterns of sex chromosomes in Melandrium album female cells
The presented data support the hypothesis that one of the two X chromosomes in M. album female cells could be inactivated and hypermethylated as described in mammals. Expand
DNA methylation of sex chromosomes in a dioecious plant, Melandrium album
Results imply that in female M. album plants, one of the two X chromosomes may be hypermethylated and inactive as described for mammalian cells (Lyon hypothesis). Expand
DNA Methylation Patterns of Melandrium Album Chromosomes
The presented data show reproducible differences in the DNA methylation patterns between the two X chromosomes in M. album female somatic cells, which indicate their distinct transcriptional activities as a possible consequence of the negative dosage compensation of X-linked genes. Expand
Fluorescence pattern of the sex-chromosomes of Melandrium dioicum, stained with quinacrine-mustard
Sex-chromosomes in a male and a female clone of M. dioicum were studied by fluorescent staining with quinacrine-mustard and the relation between fluorescence pattern and heterochromatin is discussed. Expand
Differential spiralization along mammalian mitotic chromosomes
It was observed that the chromosomes of the complement were capable of responsing to the treatment with analogs by the appearance of extended segments along their length, and the most regular and distinctive segmentation was observed in chromosomes having large late replicating regions, such as Nos. 4, 6, 9, 13, 16, X, and Y. Expand
A strong nucleotypic effect on the cell cycle regardless of ploidy level.
A positive relationship was observed between DNA C-value and cell cycle time for all species and for eudicots and monocots separately, regardless of the presence or absence of polyploid values, and the flexibility of DNA replication is explored. Expand
The Duration of Chromosomal DNA Synthesis, of the Mitotic Cycle, and of Meiosis of Higher Plants
This compilation is limited to the mitotic cycle of cells of higher plants as measured in vivo by the Quastler-Sherman method (Quastler and Sherman, 1959) which utilizes 3H-thymidine and autoradiography. Expand
Nuclear DNA content and minimum generation time in herbaceous plants
  • M. Bennett
  • Biology, Medicine
  • Proceedings of the Royal Society of London. Series B. Biological Sciences
  • 1972
It is shown that the mean cell cycle time and the mean meiotic duration in annual species is significantly shorter than in perennial species, and that satellite DNA is significant in its nucleotypic effects on developmental processes. Expand
Sex determination in plants.
It is proposed that dioecy arises either from monoecy as an environmentally unstable system controlled by plant growth substances or from hermaphroditism where the underlying mechanisms are highly stable and control does not involve plantgrowth substances. Expand
In white spruce seedlings from four provenances, the period of DNA synthesis was found to be independent of the quantity of DNA per cell, and lasted 11.1 hours on the average. The per cent G+CExpand


Differential Uptake of Tritiated Thymidine into Hetero- and Euchromatin in Melanoplus and Secale
  • A. Lima-de-faria
  • Biology, Medicine
  • The Journal of biophysical and biochemical cytology
  • 1959
In rye the asynchrony of synthesis occurs within each chromosome, and in this species during early prophase of meiosis the sex chromosome forms a heterochromatic block large enough to be resolved in tritium autoradiographs. Expand
Gene Action in the X-chromosome of the Mouse (Mus musculus L.)
Ohno and Hauschka1 showed that in female mice one chromosome of mammary carcinoma cells and of normal diploid cells of the ovary, mammary gland and liver was heteropyKnotic and suggested that the so-called sex chromatin was composed of one heteropyknotic X-chromosome. Expand
Incorporation of Tritiated Thymidine into Meiotic Chromosomes
In pachytene nuclei of Melanoplus the heterochromatin of the sex chromosome was found to synthesize DNA at a different time than the autosomal euchromatin.
A Morphological Distinction between Neurones of the Male and Female, and the Behaviour of the Nucleolar Satellite during Accelerated Nucleoprotein Synthesis
It appears not to be generally known that the sex of a somatic cell as highly differentiated as a neurone may be detected with no more elaborate equipment than a compound microscope following staining of the tissue by the routine Nissl method. Expand