Structure and inheritance of some heterozygous Robertsonian translocation in man.

Daniel, Art; Lam‐Po‐Tang, P.R.L.

doi:10.1136/jmg.13.5.381

Cited by 50 publications

(28 citation statements)

References 28 publications

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“…The metacentric chromosomes induced by this type of rearrangement are dicentric (Fig. 1), but they are stable by the suppression of one centromere (Niebuhr, 1972;Warburton et al, 1973;Daniel and Lam-Po-Tang, 1976;Daniel, 1979). This scenario also probably occurs in the mouse, since no loss of constitutive heterochromatin is detected in metacentrics induced by centric fusion (Redi et al, 1986).…”

Section: ) Stochastic Analyses Of Human Chromosomal Aberrationsmentioning

confidence: 94%

Theoretical bases for karyotype evolution. II. The fusion burst in man and mouse.

Imai

Takahata

Maruyama

et al. 1988

The Japanese journal of genetics

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As a theoretical standard for evaluating the high incidence of centric fusion in man and mouse, the relative probabilities of occurrence of reciprocal translocation (Tr), inversion (In) and centric fusion (Fu) were estimated based on the randomcontact-and-exchange model. It was shown by this model that centric fusion was extremely rare (Fu=0.0002, In=0.0521 and Tr=0.9477 for a human haploid karyotype).On the other hand, the occurrence rate of centric fusion in human newborn babies and European feral mice was about 500-1,000 times higher than the theoretically expected values, which is termed here the "fusion burst". We suggest that the fusion burst may be induced by the physical proximity of telomeres on the nuclear membrane, and the exchange of DNA strands by errors of telomere replication mechanisms.The cytogenetical significance of the fusion burst is discussed with regard to the minimum interaction hypothesis proposed by Imai et al. (1986). We suggest two closely linked possibilities that (1) the fusion burst in man and mouse can theoretically be placed in karyotype evolution as a transitional phase in the main stream of the fission-inversion cycle, and (2) it may be accelerated by some unknown (mutagenic) factors other than ionizing radiation.

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Section: ) Stochastic Analyses Of Human Chromosomal Aberrationsmentioning

confidence: 94%

Theoretical bases for karyotype evolution. II. The fusion burst in man and mouse.

Imai

Takahata

Maruyama

et al. 1988

The Japanese journal of genetics

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“…13). In humans, most Robertsonian metacentrics are dicentric (14) in that they show pericentric heterochromatin from both parental chromosomes; however, one of the centromeres is often inactive in that it does not produce a secondary constriction and region of tight sister-chromatid pairing (15). In one t(7:15)(p21;p1l), the Cbanding pericentric heterochromatin of chromosome 15 identified the second centric region, but this centromere exhibited neither a primary constriction nor tight sister-chromatid pairing and did not Cd band (16).…”

Section: Robertsonian Rearrangement Telomeres and Centromeresmentioning

confidence: 99%

Telomere replication, kinetochore organizers, and satellite DNA evolution.

Holmquist¹,

Dancis²

1979

Proc. Natl. Acad. Sci. U.S.A.

100

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Robertsonian rearrangements demonstrate one-break chromosome rearrangement and the reversible appearance and disappearance of telomeres and centromeres. Such events are quite discordant with classical cytogenetic theories, which assume all chromosome rearrangements to require at least two breaks and consider centromeres and telomeres as immutable structures rather than structures determined by mutable DNA sequences. Cytogenetic data from spontaneous and induced telomere-telomere fusions in mammals sup ort a molecular model of terminal DNA synthesis in which all ttelomeres are similar and recombine before replication and subsequent separation. This, along with evidence for a hypothetical DNA sequence, the kinetochore organizer, readily explains latent telomeres, latent centromeres, and re- Robertsonian rearrangements between rod chromosomes ( Fig. 1 upper) to produce metacentric biarmed chromosomes (Fig. 1 lower) are a common mechanism of karyotype evolution and occur spontaneously at an appreciable frequency in mammalian tissue culture (5) or even in the somatic tissue of certain fish (6). Reciprocal translocations (Fig. la) are consistent with Muller's rules. The reverse exchanges, Robertsonian fission of a metacentric into two rod chromosomes, have been observed, and some ( Fig. 1 b and c) appear as one-break rearrangements which do not require a centric fragment to supply a new centromere and telomeres to the new chromosomes (5,7,8). In addition, Robertsonian metacentrics generally possess twice the centric structure of rod chromosomes (7-10). In the grasshopper Neopodismopsis, Moens' (11) electron micrographs showed this doubled "knob"-like structure to be penetrated by twice as many microtubules as the single centric knob of rod chromosomes. Thus, a metacentric's centric region often appears doubled and capable of splitting by fission, each half becoming a functional centromere (8, 10).Robertsonian rearrangements, especially the fissions, reveal the inadequacy of Muller's rules, especially his concept of centromeres and telomeres as immutable structures (1), and imply some or all of the following: (i) dicentrics can be stable; (ii) fissions can result from one-break rearrangements; (iii) centromeres and telomeres can reversibly appear and disappear; and (iv) centromeres and telomeres can be terminal coincident structures.Dicentrics can be stable, showing parallel chromatid separation when the two centromeres are close together. Hair (12) observed an isodicentric through many vegetative generations in the plant Agropyron. The original dicentric was unstable at mitosis; criss-cross and interlocking separation produced a breakage-fusion cycle that resulted in shorter intercentric distances. Dicentrics with short intercentric regions, however, were mitotically stable, both centromeres on one chromatid separating to the same pole. Dicentrics can also be stable when one centromere is latent (see review, ref. 13). In humans, most Robertsonian metacentrics are dicentric (14) in that they show pericentric h...

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“…which were thought to be monocentric, were later shown to be dicentric, the two centromeres lying very close to each other (Niebuhr. 1972;Daniel and Lam-Po-Tang. 1976).…”

Section: Discussionmentioning

confidence: 99%

Analysis of three whole-arm translocations in a mouse sarcoma cell line

Ghosh¹,

Chaudhuri²

1984

Cytogenet Genome Res

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Three apparently whole-arm translocation chromosomes in the mouse sarcoma 180 ascites cell line have been studied by G- and C-banding and by Hoechst staining. All three chromosomes appear to have two centromeres. Both centromeres of one, which are very close together, are likely to be active and to produce parallel separation of the chromatids. The centromeres of the other two chromosomes are well separated. One of these two centromeres may be inactive either because the kinetochore organizer has been inactivated or because the kinetochore plate has been deleted, leaving the AT-rich centromeric constituative heterochromatin intact. The possibility that these whole arm translocations arose by telomeric fusion and the molecular basis of such fusions are discussed.

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Structure and inheritance of some heterozygous Robertsonian translocation in man.

Cited by 50 publications

References 28 publications

Theoretical bases for karyotype evolution. II. The fusion burst in man and mouse.

Theoretical bases for karyotype evolution. II. The fusion burst in man and mouse.

Telomere replication, kinetochore organizers, and satellite DNA evolution.

Analysis of three whole-arm translocations in a mouse sarcoma cell line

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