scholarly journals Chromosome pairing and synaptonemal complex formation in wheat-rye hybrids

1988 ◽  
Vol 53 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Xingzhi Wang ◽  
Preben Bach Holm
Keyword(s):  
Complex Formation ◽  
Synaptonemal Complex ◽  
Chromosome Pairing ◽  
Synaptonemal Complex Formation

Synaptonemal complex formation in rye (Secale cereale) heterozygous for telomeric C-bands

Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 901-907 ◽  
Author(s):  
C. B. Gillies ◽  
A. J. Lukaszewski
Keyword(s):  
Complex Formation ◽  
Synaptonemal Complex ◽  
Chromosome Pairing ◽  
Slight Reduction ◽  
Chromosome Size ◽  
Electron Microscopic ◽  
Lateral Element ◽  
Total Complement ◽  
Synaptonemal Complex Formation ◽  
The Difference

Zygotene–pachytene nuclei from a rye line heterozygous for most terminal C-bands were found by electron microscopic spreading analysis to have unequal lateral elements at most synaptonemal complex telomeres. An unpaired lateral element protruded beyond the end of the synaptonemal complex at each such telomere. Another rye line with only one C-band heterozygous telomere had only one uneven synaptonemal complex telomere. The length differences between paired lateral elements in heterozygotes (both total complement and individual synaptonemal complexes) was considerably less than the difference in DNA content or somatic metaphase chromosome size between C-band positive and C-band negative lines. There was no evidence of a synaptic adjustment effect reducing the telomere length differences in later pachytene–diplotene stage nuclei. Heterozygosity for the 1RL terminal C-band resulted in a slight reduction in chiasma frequency in that arm but no shift in chiasma position.Key words: rye, C-bands, telomeres, chromosome pairing, synaptonemal complex.

scholarly journals Chromosome-autonomous feedback down-regulates meiotic DNA break competence upon synaptonemal complex formation

2020 ◽  
Vol 34 (23-24) ◽  
pp. 1605-1618 ◽  
Author(s):  
Xiaojing Mu ◽  
Hajime Murakami ◽  
Neeman Mohibullah ◽  
Scott Keeney
Keyword(s):  
Complex Formation ◽  
Synaptonemal Complex ◽  
Synaptonemal Complex Formation ◽  
Dna Break

Chromatin structure contribution to the synaptonemal complex formation

2008 ◽  
Vol 66 (7) ◽  
pp. 1198-1208 ◽  
Author(s):  
A. Hernández-Hernández ◽  
G. H. Vázquez-Nin ◽  
O. M. Echeverría ◽  
F. Recillas-Targa
Keyword(s):  
Complex Formation ◽  
Synaptonemal Complex ◽  
Chromatin Structure ◽  
Synaptonemal Complex Formation

scholarly journals SYNAPTONEMAL COMPLEXES DURING PREMEIOTIC DNA SYNTHESIS IN OOCYTES OF DROSOPHILA MELANOGASTER

Genetics ◽  
1976 ◽  
Vol 83 (1) ◽  
pp. 67-79
Author(s):  
John W Day ◽  
Rhoda F Grell
Keyword(s):  
Complex Formation ◽  
Dna Synthesis ◽  
Synaptonemal Complex ◽  
Direct Evidence ◽  
Indirect Evidence ◽  
Female Development ◽  
Electron Microscope Autoradiography ◽  
Fourfold Increase ◽  
Microscope Autoradiography ◽  
Synaptonemal Complex Formation

ABSTRACT Well-synchronized populations of oocytes obtained by means of the "pupal system" (Grell, 1973a) have been examined to determine the time of appearance of the synaptonemal complex. The complex first appears in the most advanced oocytes between 132 and 138 hr of female development. Between 138 and 156 hr the complex apparently undergoes a fourfold increase in length. At 150 and 156 hr the complex system is extensive and present in virtually all oocytes. Previous studies using the pupal system have placed the period of premeiotic DNA synthesis between 132 and 162 hr. Thus, indirect evidence indicates that a significant portion of synaptonemal complex formation is coextensive with the main DNA replication in the oocyte. Direct evidence that DNA synthesis and complex formation occur simultaneously in oocytes has been obtained by electron microscope autoradiography. By definition, then, the stage of synaptonemal complex formation in Drosophila must include premeiotic interphase.

G-band position effects on meiotic synapsis and crossing over.

Genetics ◽  
1988 ◽  
Vol 118 (2) ◽  
pp. 307-317
Author(s):  
T Ashley
Keyword(s):  
Complex Formation ◽  
Synaptonemal Complex ◽  
Chromosomal Rearrangement ◽  
Chromosomal Rearrangements ◽  
Crossing Over ◽  
Position Effects ◽  
Band Position ◽  
Synaptonemal Complex Formation ◽  
Meiotic Synapsis ◽  
Nonhomologous Synapsis

Abstract An examination of synaptic data from a series of X-autosome translocations and crossover data from an extensive series of autosome-autosome translocations and autosomal inversions in mice has lead to the development of a hypothesis which predicts synaptic and recombinational behavior of chromosomal aberrations during meiosis. This hypothesis predicts that in heterozygotes for chromosomal rearrangements that meiotically align G-light chromatin with G-light chromatin lack of homology will be recognized. If homologous synapsis cannot proceed, synaptonemal complex formation will cease and there will be no physical suppression of crossing over in such rearrangements. However, if a chromosomal rearrangement aligns G-light chromatin with G-dark chromatin at the time of synapsis, lack of homology will not be recognized and synaptonemal complex formation will proceed nonhomologously through the G-dark chromatin. Crossing over will be physically suppressed in this region and this suppression of crossing over will be confined to the chromosome in which the G-light chromatin is nonhomologously synapsed with G-dark chromatin. When G-light chromatin is once again aligned with G-light chromatin, lack of homology again will be recognized and either homologous synapsis will be reinitiated (as in an inversion loop), or will cease altogether (as in some translocations). Unlike the previously described "synaptic adjustment", this nonhomologous synapsis of G-light with G-dark chromatin appears to compete with homologous synapsis during early pachynema.

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