Centromere orientation at metaphase I of a translocation heterozygote in lentil

1983 ◽  
Vol 25 (6) ◽  
pp. 547-553 ◽  
Author(s):  
Frida Buruchin ◽  
G. Ladizinsky
Keyword(s):  
Reciprocal Translocation ◽  
Acrocentric Chromosome ◽  
Similar Length ◽  
Translocation Heterozygote ◽  
Ring Bivalents ◽  
Acrocentric Chromosomes ◽  
Number Of Cells ◽  
Metaphase I

Reciprocal translocation between submetacentric and acrocentric chromosomes of lentil was studied. This interchange did not entail karyotypic changes. Two homomorphic ring bivalents produced by the four chromosomes of the translocation complex indicated that the long arm of the acrocentric chromosome was involved in the interchange. Chiasmata distribution in the native arms, the translocated and interstitial segments in bivalents and quadrivalents, was taken as an indication for two pairing pattern in the translocation complex. Chiasma terminalization in the short arm of the acrocentric chromosome of the translocation complex was faster in bivalents than in quadrivalents. The overwhelming number of cells with alternate-1 compared with alternate-2 orientation was attributed to the similar length of the zigzag diagonals of alternate-1 that apparently induced greater stability. The necessary elements for adjacent-2 orientation were available in the examined material but were practically absent. Pole–centromere specificity was proposed for explaining the absence of adjacent-2 in the present and other studies and the orientation of homologous centromeres to opposite poles even when they were located in different bivalents.

THREE NEW CHROMOSOMAL TRANSLOCATIONS IN HAWORTHIA

1968 ◽  
Vol 10 (3) ◽  
pp. 487-494 ◽  
Author(s):  
Herbert P. Riley ◽  
S. K. Majumdar
Keyword(s):  
Reciprocal Translocation ◽  
Acrocentric Chromosome ◽  
Centric Fusion ◽  
Metacentric Chromosome ◽  
Chromosomal Translocations ◽  
Short Chromosome ◽  
Acrocentric Chromosomes ◽  
Fusion Type

In one plant of a small-leaved form of Haworthia glauca a centric fusion type of reciprocal translocation was found between two long chromosomes with subterminal centromeres that interchanged to form a long metacentric and a short acrocentric chromosome; the latter is larger than the normal short chromosomes of the complement and consists of the short arms of the two original long chromosomes. In a typical plant of the same species a similar interchange was followed or accompanied by a second interchange between the short translocation chromosomes and a normal short chromosome to form a somewhat intermediate-sized acrocentric and a very short metacentric chromosome. In a plant of H. fulva a long and a short chromosome interchanged to produce two intermediate-sized acrocentric chromosomes. Possible evolutionary implications of these interchanges are discussed.

THE IDENTIFICATION AND MEIOTIC BEHAVIOR OF A DITELOSOMIC LINE IN AVENA SATIVA L

1970 ◽  
Vol 12 (4) ◽  
pp. 876-881 ◽  
Author(s):  
J. P. Dubuc ◽  
R. C. McGinnis
Keyword(s):  
Avena Sativa ◽  
Reciprocal Translocation ◽  
Meiotic Behavior ◽  
Telocentric Chromosome ◽  
Chromosome 20 ◽  
Ditelosomic Line ◽  
Metaphase I

A ditelosomic line was crossed with 12 identified monosomics. The metaphase I pairing was studied in the 40 + t – chromosome progenies. The telocentric chromosome was found to be homologous to the three previously identified monosomics namely, −7, −10, and −20 suggesting that the same chromosome is missing in all three lines. None of the chromosomes in monosomic condition used in the crosses except ST-7 and ST-17 from A. byzantina were involved in the reciprocal translocation present between Sun II and Garry and Rodney.The gene for normal vs. abaxial curling of the leaves was located on the short arm of chromosome 20. The genes for diploidisation and normal vs. kinky neck were located on 20L.

Interlocked bivalents in reconstructed metaphase I cells of bread wheat

1985 ◽  
Vol 75 (1) ◽  
pp. 85-92
Author(s):  
J.S. Heslop-Harrison ◽  
M.D. Bennett
Keyword(s):  
Triticum Aestivum ◽  
Light Microscopy ◽  
Bread Wheat ◽  
Chromosome Pairing ◽  
Light Microscope ◽  
Serial Sections ◽  
Ring Bivalents ◽  
Mother Cells ◽  
I Cells ◽  
Metaphase I

Complete reconstructions of all the bivalents were made from electron micrographs of serial sections through six pollen mother cells at metaphase I of meiosis in Triticum aestivum (hexaploid bread wheat). At least two of these metaphases contained interlocked pairs of bivalents. In one, two ring bivalents were interlocked, while in another a rod bivalent ran through the centre of a ring bivalent. Two other groups of bivalents were too closely appressed to allow separation into individual bivalents and may have contained interlocks. Meiosis in other anthers of the same plants examined by light microscopy was considered normal. The frequency of interlocking found was much higher than reported from light-microscope spreads. Not all interlocks in metaphase I cells need adversely affect meiosis, but knowledge of their regularity and form may facilitate understanding the processes of chromosome pairing.

Analysis of synaptonemal complexes in two fertile heterozygous boars, both carriers of a reciprocal translocation involving an acrocentric chromosome

1989 ◽  
Vol 50 (4) ◽  
pp. 220-225 ◽  
Author(s):  
H. Jaafar ◽  
O. Gabriel-Robez ◽  
C. Ratomponirina ◽  
J. Boscher ◽  
M. Bonneau ◽  
...  
Keyword(s):  
Reciprocal Translocation ◽  
Acrocentric Chromosome ◽  
Synaptonemal Complexes

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

Genetics ◽  
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.

Pachytene analysis in a 17;21 reciprocal translocation carrier: role of the acrocentric chromosomes in male sterility

1987 ◽  
Vol 77 (3) ◽  
pp. 246-250 ◽  
Author(s):  
J. M. Luciani ◽  
M. R. Guichaoua ◽  
D. Delafontaine ◽  
M. O. North ◽  
O. Gabriel-Robez ◽  
...  
Keyword(s):  
Male Sterility ◽  
Reciprocal Translocation ◽  
Translocation Carrier ◽  
Acrocentric Chromosomes

Chromosome pairing at five ploidy levels in Elymus trachycaulus

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Taing Aung ◽  
P. D. Walton
Keyword(s):  
Key Words ◽  
Chromosome Pairing ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Ploidy Levels ◽  
Elymus Trachycaulus ◽  
Ring Bivalents ◽  
Almost All ◽  
Agropyron Trachycaulum ◽  
Metaphase I

An autoallooctaploid (2n = 56) form of Elymus trachycaulus (Link) Gould ex Shinners (previously Agropyron trachycaulum (Link) Malte ex H. F. Lewis) was induced by treating allotetraploid shoots with 0.2% colchicine. Successive backcrossing to tetraploid pollen parents was successful and yielded five hexaploid (2n = 42), one pentaploid (2n = 35), and three hyperploid (2n = 31, 32, 33) plants. Metaphase I of the tetraploids was normal and 14 II chromosomes were observed, almost all of which were ring bivalents. Chromosome pairing in one octaploid, four hexploids, and one pentaploid were 4.38 IV + 0.65 III + 17.84 II + 0.85 I, 13.16 III + 0.84 II + 0.84 I, and 5.82 III + 8.18 II + 1.18 I, respectively. Efficiency of chromsome pairing (chiasmata per chromsome) was highest in tetraploids (1.29), lowest in hexaploids (0.75), and intermediate in both octaploid (0.95) and pentaploid (0.93) plants. The octaploid produced longer and broader leaves than the tetraploid, although the total dry matter produced was 14.3% lower. Total dry matter yield of the hexaploid was on an average 30.04% higher than the tetraploid and the leaves were significantly larger. The hexaploid plants were taller than both the tetraploid and the octaploid plants. Metaphase I pairing in hyperploid 1 (2n = 33) was 4.34 III + 9.66 II + 0.66 I, hyperploid 2 (2n = 32) was 2.98 III 11.03 II + 1.00 I; hyperploid 3 (2n = 30 + 1 t) was 1.97 III + 12.05 II + 0.66 I + 0.33 t. The pattern of chromosome pairing in these hyperploids suggest that they are a quintupal trisomic, a quadrupal trisomic, and a triple trisomic respectively. Backcrossing these hyperploids to euploid pollen parents was successful. Backosses and their progeny should result in a series of primary trisomiclines and some monosomic plants, which would be useful for gene mapping. Key words: octaploid, hexaploid (double triploid), pentaploid, tetraploid, hyperploid, trisomic monosomic, Agropyron.

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