Cytology of the tetraploidAllium ampeloprasum with chiasma localization

A. K. Koul; R. N. Gohil

doi:10.1007/bf01183658

The location of the major bands on chromosome 1 at diakinesis in the human male and the relationship between banding pattern and chiasma localization

Annals of Human Genetics ◽

10.1111/j.1469-1809.1985.tb01686.x ◽

1985 ◽

Vol 49 (2) ◽

pp. 147-152 ◽

Cited By ~ 1

Author(s):

D. A. LAURIE ◽

M. A. HULTÉN ◽

R. W. PALMER

Keyword(s):

Banding Pattern ◽

Chromosome 1 ◽

Human Male ◽

Chiasma Localization ◽

The Relationship

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Chiasma Localization in Four South African Grasshopper Species (Acridinae: Orthoptera)

Caryologia ◽

10.1080/00087114.1990.10797004 ◽

1990 ◽

Vol 43 (3-4) ◽

pp. 257-265

Author(s):

A. Fossey ◽

H. Liebenberg

Keyword(s):

South African ◽

Grasshopper Species ◽

Chiasma Localization

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The Form of Bivalent Chromosomes in Newt Oocytes at First Metaphase of Meiosis

Journal of Cell Science ◽

10.1242/jcs.s3-104.66.281 ◽

1963 ◽

Vol s3-104 (66) ◽

pp. 281-295

Author(s):

I. D. WATSON ◽

H. G. CALLAN

Keyword(s):

Genetic Recombination ◽

Great Majority ◽

Meiotic Metaphase ◽

Gene Products ◽

Lampbrush Chromosomes ◽

Female Sex ◽

Chiasma Localization

Lampbrush chromosomes in the ovarian oocytes of newts are associated as bivalents. Some connexions between lampbrush chromosomes are chiasmata; others are known to be fusions of gene products; yet others, namely reflected, centromere, and telomere fusions, do not appear to be due simply to the fusion of gene products. Whether chiasmata are involved in reflected, centromere, and telomere fusions cannot be decided from examination of the chromosomes at the lampbrush stage. Bivalents from oocytes at first meiotic metaphase were therefore studied. The oocytes of newts reach first meiotic metaphase after ovulation, whilst they are free in the coelome. Reflected, centromere, and the great majority of telomere fusions do not persist to first meiotic metaphase: thus chiasmata are not involved in them. In oocyte bivalents of Triturus helveticus chiasmata are not restricted in their distribution, whereas in spermatocyte bivalents of this species chiasmata are proterminally localized. In oocyte bivalents of 3 subspecies of T. cristatus chiasmata are procentrically localized, whereas in spermatocyte bivalents of these subspecies chiasmata are not restricted in their distribution. Thus in T. helveticus meiosis in the female sex is mainly responsible for genetic recombination, whereas in T. cristatus the situation is reversed. We conclude that to base genetical and evolutionary inferences on information drawn from the meiosis of one sex only is unjustified, and we doubt the validity of the claim that chiasma localization has arisen so as to restrict genetic recombination.

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Proximal chiasma localization within an interstitial chromosome segment, a likely correlate of adjacent-2 segregation of translocation causing multivalents in the mouse.

Environmental Health Perspectives ◽

10.1289/ehp.7931137 ◽

1979 ◽

Vol 31 ◽

pp. 137-140 ◽

Cited By ~ 8

Author(s):

P de Boer

Keyword(s):

Chromosome Segment ◽

Chiasma Localization

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Influence of heterochromatin on chiasma localization and terminalization in maize

Caryologia ◽

10.1080/00087114.1995.10797334 ◽

1995 ◽

Vol 48 (3-4) ◽

pp. 247-253 ◽

Cited By ~ 3

Author(s):

Rosana Torrezan ◽

Maria Suely Pagliarini

Keyword(s):

Chiasma Localization

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Heterochromatin distribution and chiasma localization in the grasshopper Bryodema tuberculata (fabr.) (Acrididae)

Chromosoma ◽

10.1007/bf00284899 ◽

1974 ◽

Vol 44 (4) ◽

pp. 393-404 ◽

Cited By ~ 24

Author(s):

I. Klášterská ◽

A. T. Natarajan ◽

C. Ramel

Keyword(s):

Chiasma Localization

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Factors affecting the meiotic pairing behaviour of B chromosomes in the grasshopper Eyprepocnemis plorans

Canadian Journal of Genetics and Cytology ◽

10.1139/g84-105 ◽

1984 ◽

Vol 26 (6) ◽

pp. 664-668 ◽

Cited By ~ 7

Author(s):

N. Henriques-Gil ◽

P. Arana ◽

J. L. Santos

Keyword(s):

Chiasma Frequency ◽

Chiasma Formation ◽

B Chromosome ◽

B Chromosomes ◽

Meiotic Pairing ◽

Eyprepocnemis Plorans ◽

Factors Affecting ◽

Chiasma Localization ◽

A Site ◽

Pairing Behaviour

A study of the meiotic behaviour of different B-chromosome variants in the acridid grasshopper Eyprepocnemis plorans demonstrates that pairing and chiasma formation in these supernumerary chromosomes depend both on genotypic factors and on the structure of the B chromosomes themselves. Genotypic effects are evidenced by the differences in chiasma frequency which the same B-chromosome combinations show in different individuals. Structural effects can be inferred from the fact that 9 of the 14 known known B variants carry a unique site to which interstitial chiasmata are confined, whereas such a site is lacking in the other five variants.Key words: B chromosomes, C-bands, chiasma frequency, chiasma localization.

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