A STUDY OF THE RELIABILITY OF SYNCHRONY IN THE DEVELOPMENT OF POLLEN MOTHER CELLS OF LILIUM LONGIFLORUM AT THE FIRST MEIOTIC PROPHASE

1977 ◽  
Vol 64 (6) ◽  
pp. 670-679 ◽  
Author(s):  
J. K. Shull ◽  
Margaret Y. Menzel
Keyword(s):  
Meiotic Prophase ◽  
Lilium Longiflorum ◽  
Pollen Mother Cells ◽  
Mother Cells

scholarly journals THE EFFECT OF X-RAYS ON CHROMOSOMES IN DIFFERENT STAGES OF MEIOSIS

1935 ◽  
Vol 19 (1) ◽  
pp. 179-198 ◽  
Author(s):  
A. Marshak
Keyword(s):  
Linear Relationship ◽  
Meiotic Prophase ◽  
Sensitive Volume ◽  
X Rays ◽  
Homologous Pairing ◽  
Linkage Mechanism ◽  
Pollen Mother Cells ◽  
X Ray ◽  
Protein Molecules ◽  
Mother Cells

1. Pollen mother cells exposed to low dosages of x-rays at various stages show different frequencies of chromosome abnormalities in the first meiotic anaphase. 2. Maximum frequencies of abnormalities were obtained in buds irradiated in the pachytene stage of the meiotic prophase and in the preceding mitosis. 3. These results are taken to indicate that the x-ray-sensitive portions of the chromonemata are closely approximated in pairs in pachytene and in the early mitotic prophase. The significance of this in relation to non-homologous pairing is indicated. 4. From the nature of the chromosome configurations observed it is concluded that chromonemata are two-parted when they synapse and that a chromonematic division occurs between pachytene and anaphase and during the mitotic prophase. 5. The frequencies of abnormalities show a linear relationship to dosage. 6. The diameter of the sensitive volume of the chromonema is calculated and found to approximate the diameter of some known protein molecules. 7. The linkage mechanism is found to make up about 90 per cent of the total sensitive volume which corresponds with the approximate reduction in length of the chromonema from pachytene to anaphase. 8. The relation of these sensitive volumes to the gene is discussed.

Fine Structure of Meiotic Prophase Chromosomes in Lilium Longiflorum

1967 ◽  
Vol 25 ◽  
pp. 88-89
Author(s):  
Peter B. Moens
Keyword(s):  
Electron Microscopy ◽  
Drosophila Melanogaster ◽  
Meiotic Prophase ◽  
Lilium Longiflorum ◽  
Nurse Cells ◽  
Tomato Plants ◽  
Regional Conference ◽  
Mother Cells ◽  
European Regional ◽  
Dipteran Species

The presence of the tripartite ribbon within synapsed homologues has been reported for a large number of sexually reproducing organisms (over one hundred species, including fungi, plants, vertebrates and invertebrates). The absence of the ribbon in some species is associated with uncommon synaptic behaviour of meiotic prophase chromosomes (Drosophila melanogaster males, Drosophila melanogaster females homozygous for synapsis suppressing mutant C3G, and achiasmatic Dipteran species, reported by G. F. Meyer, 1964, Third European Regional Conference on Electron Microscopy). The tripartite ribbon, or synaptinemal complex, may therefore be assumed to be related to pairing of homologues at meiosis. The presence of the complexes and multi-complexes in non-meiotic cells such as insect obcyte nurse cells and spermatids suggests a somewhat broader function of the complexes. This is further supported by the occurrence of complexes in non-homologous paired chromosomes in the pollen mother cells of haploid tomato plants.

Developmental changes in DNA methylation of pollen mother cells of David lily during meiotic prophase I

2010 ◽  
Vol 44 (5) ◽  
pp. 754-759 ◽  
Author(s):  
Junjun Huang ◽  
Huahua Wang ◽  
Xiaojun Xie ◽  
Huanhuan Gao ◽  
Guangqin Guo
Keyword(s):  
Dna Methylation ◽  
Meiotic Prophase ◽  
Developmental Changes ◽  
Pollen Mother Cells ◽  
Prophase I ◽  
Meiotic Prophase I ◽  
Mother Cells

FINE STRUCTURE OF CHROMOSOME COILING AT MEIOTIC PROPHASE IN RHOEO DISCOLOR

1972 ◽  
Vol 14 (4) ◽  
pp. 801-808 ◽  
Author(s):  
Peter B. Moens
Keyword(s):  
Fine Structure ◽  
Nuclear Envelope ◽  
Meiotic Prophase ◽  
Synaptonemal Complexes ◽  
Pollen Mother Cells ◽  
Mother Cells

Most, if not all of the ends of synaptonemal complexes in Rhoeo discolor pollen mother cells are attached to the nuclear envelope. At least the first 4 μm of complex adjacent to the nuclear envelope is tightly coiled. Since each of the lateral elements is associated with one chromosome it means that the two homologues of the bivalent are relationally coiled in the distal segments.

scholarly journals Cytoplasniic differentiation during microsporogenesis in higher plants

2014 ◽  
Vol 50 (1-2) ◽  
pp. 3-12 ◽  
Author(s):  
H. Dichinnson
Keyword(s):  
Meiotic Prophase ◽  
Messenger Rna ◽  
Higher Plants ◽  
Pollen Mother Cells ◽  
Cytoplasmic Rna ◽  
Low Levels ◽  
Mother Cells ◽  
New Generation

Conspicuous cytoplasmic dedifferentiation in the pollen mother cells takes place early in the meiotic prophase of many plants. This event involves the removal of much of the cytoplasmic RNA. and the differentiation of both plastids and mitochondria to approaching the sole expression of their genomes. Much of the RNA removed from the cytoplasm passes to the nucleoplasm where it is utilised in the construction of a new `generation' of ribusomes. These new ribosomes are incorporated into cytoplasmic `nuclewhich disintegrate in the post-meiotic cytoplasm, restoring its ribosomes to pre-prophase levels. These changes are interpreted as evidence of a process by which the cytoplasm is cleansed of sporophytic control elements, both for the expression of the new gametophytic genome, and in the female cells of higher plants, for transmission to the new generation. The absence of control elements (presumably long-term messenger RNA) from the cytoplasm would result in the dedifferentiation observed in the organelles, and the low levels of reserves in these cells presumably results in characteristically lengthy and unusual redifferentiation of both plastids and mitochondria, once information-carrying molecules again enter the cytosol.

CYTOMIXIS IN POLLEN MOTHER CELLS OF ONONIS (LEGUMINOSAE)

1978 ◽  
Vol 20 (3) ◽  
pp. 383-388 ◽  
Author(s):  
Pierre Morisset
Keyword(s):  
Growth Rates ◽  
Meiotic Prophase ◽  
Flower Bud ◽  
Pollen Mother Cells ◽  
Competition For Space ◽  
Mother Cells

Cytomixis occurred regularly in pollen mother cells (PMCs) of Ononis spinosa L., O. repens L. and O. arvensis L., from early meiotic prophase to telophase II. Usually only a few PMCs were affected in any anther, but occasionally whole anthers showed cytomictic patterns. Cytomixis generally was found at extremities but rarely in the median parts of anthers. Since it appeared to lead to the degeneration of affected PMCs or young microspores, it, therefore, could not give rise to aneuploidy. Cytomixis is interpreted as a pathological abnormality induced by pressure building up within the developing flower bud; it occurred where anthers pressed strongly against each other due to competition for space. It is suggested that uncoordinated growth rates of anthers and floral envelopes could account for intense cytomixis described in hybrids by various authors.

scholarly journals Nuclear Compartmentalization in Pollen Mother Cells During Meiotic Prophase

1990 ◽  
pp. 493-497
Author(s):  
M. I. Rodriguez-Garcia ◽  
J. D. Alché ◽  
A. Majewska-Sawka ◽  
M. C. Fernandez ◽  
B. Jassem
Keyword(s):  
Meiotic Prophase ◽  
Pollen Mother Cells ◽  
Mother Cells ◽  
Nuclear Compartmentalization
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