Showing papers on "Chromothripsis published in 1978"
TL;DR: The recombination type of process, which has been proposed by Resnick to explain the rejoining of radiation-induced DNA double-strand breaks, is combined with the molecular theory of radiation action to provide a description of the formation of chromosomal rearrangments.
Abstract: SummaryThe recombination type of process, which has been proposed by Resnick to explain the rejoining of radiation-induced DNA double-strand breaks, is combined with the molecular theory of radiation action to provide a description of the formation of chromosomal rearrangements. It is shown that the majority of chromosomal aberration types found at the first mitosis after radiation can be explained on the basis of one radiation-induced DNA double-strand break in the backbone of the unineme chromatid, followed by the enzymatically controlled recombinational process for the rejoining of the double-strand break. The recombinogenic process for the repair of DNA double-strand breaks relies on the close association between the broken DNA double helix and homologous DNA. The homologous nature of repeated DNA base pair sequences is used, in this model, to explain the occurrence of chromosomal exchanges between non-homologous chromosomes. The important role which repetitive DNA plays in the formation of chromosoma...
101 citations
TL;DR: There is an alternative way of explaining observations which might indicate preferential breakage or joining, and a selective screen is formed by the segregation of chromatid rearrangements and the aneuploidy tolerance levels of the early cleavage nuclei.
Abstract: Chromosome and chromatid-type rearrangements can be induced by exposure of spermatozoa of Drosophila to ionising radiation. A model, proposed to explain the formation and recovery of compound autosomes, has been extended to account for the induction of centric fragments capped by a duplication of paternal chromosome material. Three basic assumptions have been used; (1) that the sperm nucleus contains a haploid set of unreplicated chromosomes, (2) that the broken chromosomes ends can be joined together before or after replication, and (3) that one of the first two cleavage nuclei may be lost and an adult organism derived from the other. The present paper reports a theoretical application of this combination of assumptions to the general case of the formation and recovery of two-break rearrangements. This present papers led to an eludidation of the relation between repeats, compounds, fragments, amd deficiencies on the on hand and inversions and translocations on the other hand. Dicentric chromosomes and segmental aneuploidy can be simply explained. A selective screen is formed by the segregation of chromatid rearrangements and the aneuploidy tolerance, Thus there is an alternative way of explaining observations which might indicate preferential breakage or joining.
5 citations
1 citations