Karyotype analysis and identification of extra chromosomes in primary aneuploid stocks of grass pea (Lathyrus sativus L.) by fluorescence chromosome banding
TL;DR: The banding pattern is analyzed to reveal the identity of extra chromosome(s) involved in these 20 aneuploid types in grass pea and DNA-base specific chromomycin A3 (CMA) and 4,6ʹdiamidino-2-phenylindole (DAPI) banding patterns are employed.
Abstract: Prominent primary aneuploid stocks namely seven primary trisomics, seven primary tetrasomics, and six double trisomic types were earlier developed in grass pea (Lathyrus sativus L.), a hardy legume. Despite distinct morphological features, identity and nature of their extra chromosome(s) were elusive, hampering assignment of desirable breeding traits into specific linkage groups. The present study aims to analyze the banding pattern and to reveal the identity of extra chromosome(s) involved in these 20 aneuploid types in grass pea. Conventional orcein banding was first done using the root-tip squash technique in all aneuploids along with disomic (2n = 2x = 14) parent, and karyomorphological features were noted. Chromosomes were classified following the total length of individual chromosomes and arranged in order of decreasing sizes, keeping their centromeres in a straight line. DNA-base specific chromomycin A3 (CMA) and 4,6ʹdiamidino-2-phenylindole (DAPI) banding pattern were finally employed to c...
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TL;DR: The mitotic checkpoint is a major cell cycle control mechanism that guards against chromosome missegregation and the subsequent production of aneuploid daughter cells.
Abstract: The mitotic checkpoint is a major cell cycle control mechanism that guards against chromosome missegregation and the subsequent production of aneuploid daughter cells. Most cancer cells are aneuploid and frequently missegregate chromosomes during mitosis. Indeed, aneuploidy is a common characteristic of tumours, and, for over 100 years, it has been proposed to drive tumour progression. However, recent evidence has revealed that although aneuploidy can increase the potential for cellular transformation, it also acts to antagonize tumorigenesis in certain genetic contexts. A clearer understanding of the tumour suppressive function of aneuploidy might reveal new avenues for anticancer therapy.
795 citations
TL;DR: The history of studies on aneuploidy is reviewed, some of its major characteristics are summarized and speculations as to whether and how aneuPLoidy contributes to tumorigenesis are considered.
Abstract: A change in chromosome number that is not the exact multiple of the haploid karyotype is known as aneuploidy. This condition interferes with growth and development of an organism and is a common characteristic of solid tumors. Here, we review the history of studies on aneuploidy and summarize some of its major characteristics. We will then discuss the molecular basis for the defects caused by aneuploidy and end with speculations as to whether and how aneuploidy, despite its deleterious effects on organismal and cellular fitness, contributes to tumorigenesis.
384 citations
"Karyotype analysis and identificati..." refers background in this paper
...to genomic instability, anomalous cell division processes, karyomorphological polymorphisms, and alterations in metabolic processes, resulting in reproductive anomaly, sterility, and cell proliferation or tumorigenesis in both plants and animals (Torres et al. 2008; Holland and Cleveland 2009)....
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...…to genomic instability, anomalous cell division processes, karyomorphological polymorphisms, and alterations in metabolic processes, resulting in reproductive anomaly, sterility, and cell proliferation or tumorigenesis in both plants and animals (Torres et al. 2008; Holland and Cleveland 2009)....
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TL;DR: Several critical points of speciation-related chromosomal change are drawn attention, namely: (a) interrelations between chromosomal rearrangements and repetitive DNA fraction; (b) mobility of ribosomal DNA clusters; and (c) rDNA and transposable elements as perpetual generators of genome instability.
Abstract: Chromosomal change is one of the more hotly debated potential mechanisms of speciation. It has long been argued over whether--and to what degree--changes in chromosome structure contribute to reproductive isolation and, ultimately, speciation. In this review we do not aim to completely analyze accumulated data about chromosomal speciation but wish to draw attention to several critical points of speciation-related chromosomal change, namely: (a) interrelations between chromosomal rearrangements and repetitive DNA fraction; (b) mobility of ribosomal DNA clusters; and (c) rDNA and transposable elements as perpetual generators of genome instability.
254 citations
"Karyotype analysis and identificati..." refers background in this paper
...NORs are heterochromatic rich domains and reportedly found to exhibit fragility and mobility, linked with the activation of the transposable elements located near or within rDNA clusters in many plant species (Guera 2000; Huang et al. 2008; Raskina et al. 2008)....
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...are heterochromatic rich domains and reportedly found to exhibit fragility and mobility, linked with the activation of the transposable elements located near or within rDNA clusters in many plant species (Guera 2000; Huang et al. 2008; Raskina et al. 2008)....
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TL;DR: A comprehensive overview of somatic and meiotic defects that lead to polyploidy or structural genome changes and their relevance for plant genome evolution and speciation is provided and their putative role in boosting adaptive genome evolution in hostile environments is elaborate.
200 citations
TL;DR: The C-band distribution patterns of 105 angiosperm species were compared and showed that heterochromatin was preferentially located in similar chromosome regions, regardless of the distance from the centromere.
Abstract: The C-band distribution patterns of 105 angiosperm species were compared to identify general patterns or preferential sites for heterochromatin. The base-specific fluorochrome reaction of heterochromatin for 58 of these species and the role played by the average chromosome size in band distribution were also considered. The results showed that heterochromatin was preferentially located in similar chromosome regions, regardless of the distance from the centromere. This trend results in generalized bands, with heterochromatin distribution being identical in most chromosomes of a karyotype. Such bands very often displayed the same fluorochrome reaction, suggesting possible repeat transfer between non-homologous sites. Chromosome size may also play a role in heterochromatin location, since proximal bands were much more common in small-sized chromosomes.
193 citations