Synaptonemal complexes in premeiotic interphase of pollen mother cells of Triticum aestivum

Chromosoma ◽  
1977 ◽  
Vol 63 (2) ◽  
pp. 153-159 ◽  
Author(s):  
H. A. McQuade ◽  
B. Bassett
Keyword(s):  
Triticum Aestivum ◽  
Synaptonemal Complexes ◽  
Pollen Mother Cells ◽  
Mother Cells

scholarly journals The Organization and Polarity of Pollen Mother Cells of Triticum Aestivum

1972 ◽  
Vol 11 (3) ◽  
pp. 699-711
Author(s):  
G. A. DOVER
Keyword(s):  
Triticum Aestivum ◽  
Ploidy Levels ◽  
Pollen Mother Cells ◽  
Time Of Application ◽  
Naturally Occurring ◽  
Aegilops Sharonensis ◽  
Pollen Types ◽  
Tapetal Cells ◽  
Meiotic Spindles ◽  
Mother Cells

Colchicine has been applied to young developing anthers of Triticum aestivum at varying stages of maturity from the last premeiotic mitoses of the archesporial and tapetal cells to the second meiotic divisions of the pollen mother cells. The developmental stage of the archesporium at which colchicine took effect was determined by cytological examination of the ploidy levels of the nuclei of the adjacent tapetal cells. The type of pollen abnormality induced depended on the time of application and the concentration of colchicine. Uninucleate monads with 4 randomly positioned pores and uninucleate monads without pores were obtained with 0.5% colchicine. Multipored polyads and multipored uninucleate monads were observed together in anthers treated with 0.01% colchicine. Naturally occurring aberrant pollen types in hybrids of Triticum aestivum x Aegilops mutica or T. aestivum x Aegilops sharonensis have revealed a constant relationship between the disposition of the meiotic spindles and the siting of the pollen pores. The colchicine-induced abnormalities have further clarified the nature of this relationship leading to the interpretation that both the positioning of the spindles and the siting of the pores are predetermined by events taking place in the premeiotic interphase at a time just after the last mitosis of the pollen mother cells and the penultimate mitosis of the tapetum. A reorganization of the archesporial cells (sensitive to colchicine) possibly occurs at this time. Various subsequent meiotic events are dependent on the reorganization. Two of these events - the organization of meiotic spindles and the establishment of pollen symmetry - are discussed.

Meiosis in triploid Lolium. I. Synaptonemal complex formation and chromosome configurations at metaphase I in aneuploid autotriploid L. multiflorum

Genome ◽  
1994 ◽  
Vol 37 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Huw M. Thomas ◽  
Barry J. Thomas
Keyword(s):  
Complex Formation ◽  
Synaptonemal Complex ◽  
Lolium Multiflorum ◽  
Synaptonemal Complexes ◽  
Pollen Mother Cells ◽  
Partner Exchange ◽  
Synaptonemal Complex Formation ◽  
Mother Cells ◽  
Axial Element ◽  
Metaphase I

A spreading technique for synaptonemal complexes (SCs) was applied to pollen mother cells of two aneuploid genotypes of autotriploid Lolium multiflorum (2n = 3x + 1 = 22). In the earliest nuclei analyzed the axial elements are in six groups of 3 and one group of 4. Most groups have formed multivalents with from one to five pairing partner exchanges, but there are also groups that have formed bivalents and univalents. Some axial elements have formed triple associations, in one case for the length of the trivalent. Unsynapsed axial elements remain aligned with their homologous SCs into pachytene, but this alignment is abolished as these axes pair heterologously among themselves until the entire axial element complement is synapsed. At metaphase I most chromosomes are associated as trivalents and quadrivalents.Key words: Lolium, triploid, pairing partner exchange, chiasma, multivalent.

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.

The duration of meiosis in pollen mother cells of wheat, rye and Triticale

1971 ◽  
Vol 178 (1052) ◽  
pp. 259-275 ◽  
Keyword(s):  
Triticum Aestivum ◽  
Dna Synthesis ◽  
Secale Cereale ◽  
Sampling Methods ◽  
Tritiated Thymidine ◽  
Pollen Mother Cells ◽  
Mother Cells

The duration of meiosis and its stages at 20 °C has been determined in wheat ( Triticum aestivum 2 n = 6 x = 42), in rye ( Secale cereale 2 n = 14) and in Triticale (2 n = 8 x = 56) by sampling methods and by timing the intervals between the pre-meiotic DNA synthesis and meiotic stages following the incorporation of tritiated thymidine. The results from all the methods used were in general agreement. Meiosis takes about 24 h in wheat, 21 h in Triticale and about 51 h in rye. The lengths of the meiotic stages relative to that of the division correspond reasonably well in the three forms studied but zygotene and pachytene were much longer in rye than in wheat and Triticale .

scholarly journals The Development and Meiotic Behavior of Asymmetrical Isochromosomes in Wheat

Genetics ◽  
1997 ◽  
Vol 145 (4) ◽  
pp. 1155-1160
Author(s):  
Adam J Lukaszewski
Keyword(s):  
Triticum Aestivum ◽  
Hexaploid Wheat ◽  
Triticum Aestivum L ◽  
Meiotic Metaphase ◽  
Meiotic Behavior ◽  
Pollen Mother Cells ◽  
Chromosome Arm ◽  
Mother Cells ◽  
Metaphase I

To determine which segments of a chromosome arm are responsible for the initiation of chiasmate pairing in meiosis, a series of novel isochromosomes was developed in hexaploid wheat (Triticum aestivum L.). These isochromosomes are deficient for different terminal segments in the two arms. It is proposed to call them “asymmetrical.” Meiotic metaphase I pairing of these asymmetrical isochromosomes was observed in plants with various doses of normal and deficient arms. The two arms of an asymmetrical isochromosome were bound by a chiasma in only two of the 1134 pollen mother cells analyzed. Pairing was between arms of identical length whenever such were available; otherwise, there was no pairing. However, two arms deficient for the same segment paired with a frequency similar to that of normal arms, indicating that the deficient arms retained normal capacity for pairing. Pairing of arms of different length was prevented not by the deficiency itself, but rather, by the heterozygosity for the deficiency. Whether two arms were connected via a centromere in an isochromosome or were present in two different chromosomes had no effect on pairing. This demonstrates that in the absence of homology in the distal regions of chromosome arms, even if relatively short, very long homologous segments may remain unrecognized in meiosis and will not be involved in chiasmate pairing.

Chromosome localization of genes that control synchronous development of pollen mother cells in wheat

Caryologia ◽  
2003 ◽  
Vol 56 (3) ◽  
pp. 275-279 ◽  
Author(s):  
Wei Li ◽  
Jun Yang ◽  
You-Fu Pan ◽  
Guang-Qin Guo ◽  
Guo-Chang Zheng
Keyword(s):  
Chromosome Localization ◽  
Pollen Mother Cells ◽  
Synchronous Development ◽  
Mother Cells

An ultrastructural study of cytomixis in tobacco pollen mother cells

PROTOPLASMA ◽  
2011 ◽  
Vol 248 (4) ◽  
pp. 717-724 ◽  
Author(s):  
Sergey R. Mursalimov ◽  
Elena V. Deineko
Keyword(s):  
Ultrastructural Study ◽  
Pollen Mother Cells ◽  
Tobacco Pollen ◽  
Mother Cells
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