Synaptonemal complex pairing and metaphase I association in a telo-substituted telotrisomic of rye (Secale cereale L.)

A comparative analysis of synaptonemal complex formation at pachytene and chromosome association at metaphase I was carried out in heterozygotes for translocation T242W (2R/6R) of rye (Secale cereale L.). Synaptonemal complex formation supported earlier light microscopic observations that one exchanged segment of this translocation was very small and restricted to the telomere or had been lost. Negative interference between the interstitial segments with respect to chiasma formation was detected at metaphase I. This interference was apparently the result of the simultaneous occurrence of either asynapsis or nonhomologous pairing around the translocation point at pachytene. Negative interference detected across the centromere of 6R was attributed to nonhomologous pairing. The presence of an intercalary C-band in the interstitial segment 2RLi or in the 1RS arm had no apparent influence on synaptonemal complex formation. Unmatched ends of synaptonemal complex 1R and of the multivalent were in most cases associated with heterozygosity for the telomeric C-heterochromatin.Key words: Secale cereale, translocation, synapsis, interference, C-banding.

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Evidence of nonchiasmate bonds at metaphase I in inbred rye

Canadian Journal of Genetics and Cytology ◽

10.1139/g84-066 ◽

1984 ◽

Vol 26 (4) ◽

pp. 409-414 ◽

Cited By ~ 7

Author(s):

M. C. Cermeño ◽

J. Orellana ◽

J. R. Lacadena

Keyword(s):

Secale Cereale ◽

Chiasma Frequency ◽

Meiotic Pairing ◽

Secale Cereale L ◽

Chromosome 1R ◽

Metaphase I

The loss of bound chromosome arms through early, middle, and late metaphase I has been analyzed in a plant of inbred rye (Secale cereale L.) heterozygous for a terminal heterochromatic C-band of the long arm of chromosome 1R. From the increase in the number of univalent pairs due to bound arm loss, and from the comparison between the frequencies of bound arms at metaphase I and recombinant chromosomes at anaphase I, it is concluded that some of the chromosome bonds appearing at metaphase I are actually nonchiasmate associations that can be considered as remnants of prophase pairing. Conclusions concerning recombination obtained solely from the analysis of chiasma frequency measured as bound arms may be invalid.Key words: inbred rye, C-heterochromatin, meiotic pairing, nonchiasmate bonds.

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ASSOCIATION OF ISOZYMES WITH A RECIPROCAL TRANSLOCATION IN CULTIVATED RYE (SECALE CEREALE L.)

Genetics ◽

10.1093/genetics/109.1.177 ◽

1985 ◽

Vol 109 (1) ◽

pp. 177-193

Author(s):

Ana M Figueiras ◽

Maria T Gonzalez-Jaen ◽

Julio Salinas ◽

Cesar Benito

Keyword(s):

Secale Cereale ◽

Reciprocal Translocation ◽

Chromosome Arrangement ◽

Electrophoretic Patterns ◽

Meiotic Configuration ◽

Chromosome Arm ◽

Secale Cereale L ◽

Metaphase I

ABSTRACT In rye (Secale cereale L. cv. "Ailés") the progeny of a cross between a structural heterozygote for a reciprocal translocation (involving the 1R chromosome) and a homozygote for the standard chromosome arrangement were analyzed for the electrophoretic patterns of eight different leaf isozymes and also for their meiotic configuration at metaphase I.—The Got-3 and Mdh-2b loci are linked to each other and also to the reciprocal translocation. The Mdh-2b locus is located in the interstitial segment of the 3Rq chromosome arm, with an estimated distance of 8 cM to the breakpoint. Therefore, the reciprocal translocation involves the 1R and 3R chromosomes.—Also, the Mdh-1 and 6-Pgd-2 loci are linked (16 ± 3 cM) and have been located on the 2Rq arm. Finally, the Per-3 and Per-4 loci are located on the 2Rp chromosome arm at an estimated distance of 26 ± 4 cM.

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Synaptonemal complex formation and metaphase I configuration patterns in a translocation heterozygote of rye (Secale cereale)

Genome ◽

10.1139/g89-413 ◽

1989 ◽

Vol 32 (1) ◽

pp. 72-81 ◽

Cited By ~ 10

Author(s):

J. H. de Jong ◽

J. van Eden ◽

J. Sybenga

Keyword(s):

Complex Formation ◽

Synaptonemal Complex ◽

Secale Cereale ◽

Chiasma Formation ◽

Terminal Segment ◽

Pachytene Nucleus ◽

Synaptonemal Complexes ◽

Synaptonemal Complex Formation ◽

Chromosome 1R ◽

Metaphase I

Four rye plants heterozygous for translocation 248, involving chromosomes 1R and 6R, were used for a comparative study of synaptonemal complex formation at midprophase I and chromosome configurations at metaphase I. Synaptonemal complexes were obtained with a cell-spreading technique and studied with electron microscopy. The total length of the synaptonemal complexes in the 28 analyzable pachytene nuclei varied considerably, both within and among plants. The variation of synaptonemal complex lengths of the bivalents in a nucleus was partly stage dependent; i.e., it was greater at early than at late pachytene. In all but one pachytene nucleus, pairing in the quadrivalent was regular, and the four pairing arms were usually easy to identify. Most noticeable was the variation of pairing saturation at the breakpoint of the quadrivalent. Pairing in the breakpoint region was delayed with respect to the pairing in the bivalents. Variation in the arm lengths of the quadrivalent was the result of incomplete and nonhomologous pairing at the breakpoint as well as differential contraction rates among chromosome segments. It was shown that the completion of delayed pairing throughout pachytene is mainly long-arm pairing. The actual breakpoint was therefore not in the middle of the unpaired segments, but more distal. The analysis of metaphase I nuclei revealed that chiasma frequency in this material was higher than in similar material used in former studies. When one of the translocation segments lacked a chiasma, this was in most cases the short translocated segment 1RS, the terminal segment of the satellite of chromosome 1R. Positive chiasma interference was demonstrated between the interstitial and exchanged segment in 1RS. This agreed with the observation of a negative correlation in extent of pairing between these two segments. Other interference phenomena, which have been described for this translocation in other material, remained undetected because of lack of variation in chiasma formation owing to high chiasma frequency.Key words: Secale cereale, meiosis, translocation, synaptonemal complex, metaphase I.

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Synaptic abnormalities in spread nuclei of Secale. I. Inbred lines

Genome ◽

10.1139/g95-097 ◽

1995 ◽

Vol 38 (4) ◽

pp. 764-771 ◽

Cited By ~ 3

Author(s):

M. Martínez ◽

C. Cuadrado ◽

C. Romero

Keyword(s):

Complex Formation ◽

Synaptonemal Complex ◽

Secale Cereale ◽

Inbred Lines ◽

Meiotic Behaviour ◽

Synaptonemal Complex Formation ◽

Metaphase I

The meiotic behaviour at metaphase I of two inbred lines of Secale cereale showed a decrease in the frequency of bound arms and the presence of univalents. The study of synaptonemal complex formation revealed that these inbred lines had asynapsis and many nuclei did not complete the pairing process. Synaptic abnormalities such as fold-back loops, short pairing partner switches, interstitial nonhomologous pairing regions, and asynchrony between bivalents were associated and correlated with interlocking. It is suggested that the asynapsis is due to a failure in the interlocking repair. All these abnormalities could affect the formation and maintenance of chiasmata and so could explain the metaphase I behaviour of these inbred lines and the differences between them.Key words: inbred lines, Secale cereale, synaptonemal complex, spreading, synaptic abnormalities.

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Centromere Co-orientation at metaphase I in interchange heterozygotes of rye, Secale cereale L.

Chromosoma ◽

10.1007/bf00327057 ◽

1977 ◽

Vol 64 (2) ◽

pp. 175-189 ◽

Cited By ~ 12

Author(s):

J. R. Lacadena ◽

M. Candela

Keyword(s):

Secale Cereale ◽

Secale Cereale L ◽

Metaphase I

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Relation between loss of chromosome associations at metaphase I and interference estimates in rye

Genome ◽

10.1139/g88-004 ◽

1988 ◽

Vol 30 (1) ◽

pp. 19-24

Author(s):

A. Roca ◽

T. Naranjo ◽

P. G. Goicoechea ◽

R. Giraldez

Keyword(s):

Secale Cereale ◽

Translocation Breakpoint ◽

Negative Interference ◽

Secale Cereale L ◽

Chromosome Associations ◽

I Cells ◽

Chiasma Interference ◽

Metaphase I

Interference between metaphase I associations (bonds) in specific segments of the chromosomes involved in translocation T242W of rye has been studied. Different values of coincidence were obtained at mid- and late metaphase I for all segment pairs analyzed. At mid-metaphase I there is negative interference between segments opposite to the translocation breakpoint and there is no cross-centromere interference. At late metaphase I there is negative interference in all these segment pairs. The comparison between mid- and late metaphase I cells also indicated that the frequency with which some of these segments are associated decreases along this stage. The possible causes of this decrease and its relation to the differences in coincidence estimates are discussed.Key words: Secale cereale L., translocations, chiasma interference.

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Synapsis and chiasma formation in a ditelo-substituted haploid of rye

Genome ◽

10.1139/g91-018 ◽

1991 ◽

Vol 34 (1) ◽

pp. 109-120 ◽

Cited By ~ 15

Author(s):

J. H. de Jong ◽

F. Havekes ◽

A. Roca ◽

T. Naranjo

Keyword(s):

Synaptonemal Complex ◽

Secale Cereale ◽

Chiasma Formation ◽

Chromosome Length ◽

C Banding ◽

Chromosome Associations ◽

Synaptonemal Complex Formation ◽

Chromosome 1R ◽

In Cells ◽

Metaphase I

Synapsis and chiasma formation were analyzed in a ditelo-substituted haploid of rye (Secale cereale), in which chromosome 1R was replaced by its telosomes. The study was made by comparing synaptonemal complex formation at early meiotic prophase I, chromosome associations at metaphase I, and recombinant chromosomes at anaphase I and prophase II. For the analysis of synaptonemal complexes, 41 nuclei at stages ranging from leptotene to early diplotene were selected. In the leptotene and early zygotene nuclei, numerous alignments of axial cores involving the same or different chromosomes were observed. Pairing initiation sites occurred at both interstitial and distal segments. Throughout zygotene the extent of pairing gradually increases, with values up to 84.8% at a stage that is morphologically comparable with late pachytene. Pairing-partner exchanges were frequently observed in zygotene nuclei, giving rise to multiple associations encompassing all or most of the chromosomes. In cells at metaphase I multivalents were very rare (2%), indicating elimination of most pairing-partner exchanges. In cells at metaphase I, anaphase I, and prophase II chromosome length, centromere position, and C-banding pattern enable the identification of the chromosomes 1RS, 1RL, 4R, 5R, and 6R, and the distinction of three metacentric chromosomes (RM1, RM2, and RM3). Metaphase I bonds were found to be nonrandomly distributed. Associations between the arms 4RL, 5RL, 6RL, and RM1L, all of them without telomeric C-bands, were more frequent than between the remaining arms. The bonds were mainly located at the distal parts of the chromosomes. The frequency of recombinant chromosomes at anaphase I or prophase II suggests that metaphase I bonds were true chiasmata.Key words: Secale cereale, haploid, synaptonemal complex, chiasmate bonds, C-banding.

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Meiotic chromosome interactions in inbred autotetraploid rye (Secale cereale)

Genome ◽

10.1139/g93-016 ◽

1993 ◽

Vol 36 (1) ◽

pp. 131-138 ◽

Cited By ~ 12

Author(s):

R. Chatterjee ◽

G. Jenkins

Keyword(s):

Synaptonemal Complex ◽

Secale Cereale ◽

Statistical Tests ◽

Meiotic Chromosome ◽

Chiasma Formation ◽

Significant Drop ◽

Direct Observations ◽

Secale Cereale L ◽

Surface Spread ◽

Two Stages

Electron microscopy of whole-mount surface-spread synaptonemal complex complements and conventional light microscopy of chromosomes at first metaphase of meiosis were used to compare the relative frequencies of pairing configurations at the two stages in inbred autotetraploid rye (Secale cereale L.). Statistical tests showed significantly fewer multivalents at first metaphase than expectations based on random initiation of synapsis at each telomeric site within each group of four homologues. Direct observations of synaptic behaviour of chromosomes showed that this deviation is due primarily to a preponderance of bivalents during zygotene and pachytene. It is also the result of a significant drop in multivalent frequency from meiotic prophase to metaphase I, which is attributable both to a lack of chiasmata with which to consolidate multivalents and inhibition of chiasma formation in synaptonemal complex segments of multivalents that are nonhomologous.Key words: autotetraploid, rye, synaptonemal complex, multivalents, chiasmata.

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Effet antioxydant et antihyperglycémiant du seigle (Secale cereale L.) et du sorgho (Sorghum bicolor L.) chez le rat Wistar rendu diabétique

Phytothérapie ◽

10.3166/phyto-2018-0013 ◽

2018 ◽

Vol 16 (S1) ◽

pp. S273-S283

Author(s):

Z. Mami-Soualem ◽

N. Brixi ◽

C. Beghdad ◽

M. Belarbi

Keyword(s):

Sorghum Bicolor ◽

Secale Cereale ◽

Stress Oxydant ◽

Habitudes Alimentaires ◽

Diabète Sucré ◽

Secale Cereale L ◽

Vitamine C ◽

Fibres Alimentaires ◽

Peroxydation Lipidique ◽

Sorghum Bicolor L

Le changement des habitudes alimentaires au cours de ces dernières années a abouti à l’apparition des maladies dites de civilisation, parmi elles le diabète sucré. Des approches diétothérapeutiques privilégient la consommation des produits céréaliers sous la forme la plus complète possible. Ce travail a pour but de tester l’efficacité des régimes expérimentaux préparés à base des grains complets des deux céréales, le sorgho (Sorghum bicolor L.) et le seigle (Secale cereale L.), sur la correction de l’hyperglycémie et des marqueurs du stress oxydant associés au diabète chez le rat mâle Wistar. Les résultats montrent que les rats diabétiques, soumis au régime seigle pendant quatre semaines, présentent une diminution significative de la glycémie qui atteint les 53,95 % à la fin de l’expérimentation, ce qui fait que leur taux en glycémie se rapproche de celui des normoglycémiques. Le sorgho blanc présente, d’une part, une diminution significative de la peroxydation lipidique intracellulaire et, d’autre part, une augmentation de l’activité de la glutathion peroxydase, la glutathion réductase ainsi que la vitamine C. Ces approches méthodologiques peuvent, en améliorant la connaissance de l’importance des céréales (fibres alimentaires solubles et des polyphénols) dans l’évolution du diabète, aboutir à des recommandations et à une éducation nutritionnelle du diabétique.

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