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Bogdanov, Yu. F.

doi:10.1023/a:1023345311889

Cited by 28 publications

(9 citation statements)

References 47 publications

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“…In species lacking SCs, the cohesin complexes themselves were suggested to assemble the recombination machinery. In these cases, Maguire suggested the presence of rudimentary small SCs located between cohesed centromeres and pointed out that REC8 conserved through evolution since the proto-eukaryotes [46,102] may be involved, which we consistently found in tumours at these same sites. In particular, it is possible because the mitotic G2 DNA damage checkpoint and recombination checkpoint of meiotic prophase have similar molecular regulators [103] allowing DNA damaged tumour cells to glide from mitotic G2 arrest into meiotic prophase [60].…”

Section: Discussionsupporting

confidence: 56%

“…It is no surprise that our studies of the ploidy cycles of genotoxically stressed somatic tumours have drawn upon the early evolutionary forms of meiosis and syngamy [46,47,49,50]. In particular, in the absence of SCs, DNA recombination repair can start between the satellite DNA of the two cohesed centromeres.…”

Section: Discussionmentioning

confidence: 99%

“…However, the relationship of canonical meiosis to a currently designated "meio-mitosis" in somatic cancer cells remains unresolved [42]. Moreover, the evolution of meiosis and sexual reproduction are still the subject of ongoing discussions [43][44][45][46][47][48][49][50]. Recently, protistologists paid attention to the similarity of amoebal life-cycles, including the polyploidy phase, with the "lifecycles" of resistant tumour cells [51][52][53].…”

Section: Introductionmentioning

confidence: 99%

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The Cancer Aneuploidy Paradox: In the Light of Evolution

Salmiņa

Huna

Kalējs

et al. 2019

Preprint

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Aneuploidy should compromise cellular proliferation but paradoxically favours tumour progression and poor prognosis. Here, we consider this paradox in terms of our most recent observations of chemo/radio-resistant cells undergoing reversible polyploidy. The latter perform segregation of two parental groups of end-to-end linked dyads by pseudo-mitosis creating tetraploid cells through a dysfunctional spindle. This is followed by autokaryogamy and homologous pairing preceding a bi-looped endo-prophase. The associated RAD51 and DMC1/γ-H2AX double-strand break repair foci are tandemly situated on the AURKB/REC8/kinetochore doublets along replicated chromosome loops, indicative of recombination events. MOS-associated REC8-positive peri-nucleolar centromere cluster organises a monopolar spindle. The process is completed by reduction divisions (bi-polar or with radial cytotomy including pedogamic exchanges) and release of secondary cells and/or formation of an embryoid.  Together this process preserves genomic integrity and chromosome pairing, while tolerating aneuploidy by by-passing the mitotic spindle and meiotic SC checkpoints. Concurrently, it reduces the chromosome number and facilitates recombination that decreases the mutation load of aneuploidy and lethality in the chemo-resistant tumour cells. This cancer life-cycle has parallels both within the cycling polyploidy of the asexual life cycles of ancient unicellular protists and cleavage embryos of early multicellulars, supporting the atavistic theory of cancer.

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Section: Discussionsupporting

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Cancer Aneuploidy Paradox: In the Light of Evolution

Salmiņa

Huna

Kalējs

et al. 2019

Preprint

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“…If, however, the third quadrupole is set up to work in SIM mode with low mass resolution and uniformly transfer all of the masses of the product ion, a scan of the first quadrupole around the molecular ion group of isotopomers will generate the true, nascent isotope abundance of the molecular ions. As is known [2][3][4][5][6][7][8][9][10][11][12][13] such isotope abundance can be used to derive possible elemental formulae with declining order of matching to the experimental data.…”

Section: The Isotope Abundance Analysis Ms/ms Methodsmentioning

confidence: 99%

“…We recently developed a new isotope abundance analysis (IAA) method and software 2,3 which we named Tal-Aviv. Various forms of IAA have also been described by several other authors [4][5][6][7][8][9][10][11][12][13] The Tal-Aviv IAA software is used to derive elemental formula information from experimental mass spectral data of molecular ion isotopomeric abundances. The software can also be used to automatically confirm or reject the search results coming from an EI spectral library search application such as NIST (National Institute of Standards and Technology), 14 thereby significantly improving the confidence level in sample identifications.…”

mentioning

confidence: 99%

Isotope abundance analysis for improved sample identification with tandem mass spectrometry

Alon¹,

Amirav²

2009

Rapid Comm Mass Spectrometry

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Tandem mass spectrometry (MS/MS) is widely used for trace level sample analysis in complex mixtures. However, sample identification in MS/MS is challenging and not as trustworthy as with electron ionization (EI) mass spectral libraries. This paper presents a novel method for the combination of isotope abundance analysis (IAA) and EI-MS/MS for improved sample identification even at trace level in complex matrices. Accordingly, the first quadrupole is scanned in a narrow range around the molecular ion group of isotopomers such as M+, [M+1]+ and [M+2]+, Q2 serves for collision-induced dissociation to produce product ions while Q3 transfers the major sample product ions with low resolution, thus encompassing and uniformly transmitting all the product ion isotopomers. IAA can then be used to derive elemental formula information from the cleansed experimental data. IAA-MS/MS was experimentally tested with perfluorotributylamine and a very good matching factor of 995 (out of 1000) was obtained for IAA on m/z 502, 503 and 504 (fragment ion isotopomers) while Q3 transmitted the m/z 264 product ion with a mass window of 6 m/z units. The IAA-MS/MS method was further tested with the pesticide diazinon on its molecular ions m/z 304, 305 and 306 while Q3 was locked on its m/z 179 product ion with a mass window of 6 m/z units. Again, very good matching factors were obtained, even for 40 pg diazinon on-column during its GC/MS analysis (match = 981). IAA-MS/MS combines the traditional benefits of MS/MS in the removal of matrix interferences with the IAA power of elemental analysis.

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The diverse roles of transverse filaments of synaptonemal complexes in meiosis

Boer

Heyting

2006

Chromosoma

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In most eukaryotes, homologous chromosomes (homologs) are closely apposed during the prophase of the first meiotic division by a ladderlike proteinaceous structure, the synaptonemal complex (SC) [Fawcett, J Biophys Biochem Cytol 2:403-406, 1956; Moses, J Biophys Biochem Cytol 2: [215][216][217][218] 1956]. SCs consist of two proteinaceous axes, which each support the two sister chromatids of one homolog, and numerous transverse filaments (TFs), which connect the two axes. Organisms that assemble SCs perform meiotic recombination in the context of these structures. Although much information has accumulated about the composition of SCs and the pathways of meiotic crossing over, several questions remain about the role of SCs in meiosis, in particular, about the role of the TFs. In this review, we focus on possible role(s) of TFs. The interest in TF functions received new impulses from the recent characterization of TF-deficient mutants in a number of species. Intriguingly, the phenotypes of these mutants are very different, and a variety of TF functions appear to be hidden behind a façade of morphological conservation. However, in all TFdeficient mutants a specific class of crossovers that display interference is affected. TFs appear to create suitable preconditions for the formation of these crossovers in most species, but are most likely not directly involved in the interference process itself. Furthermore, TFs are important for full-length homolog alignment. (Fig. 1). Assembly and composition of synaptonemal complexesCohesins, which are proteins that mediate cohesion between sister chromatids (reviewed by Nasmyth 2005), are important for AE assembly (Klein et al. 1999;Pelttari et al. 2001). During S-phase, both in the mitotic cycle and in premeiotic S-phase, cohesins are installed in such a way that they hold the newly synthesized sister chromatids together. In the mitotic cycle, all sister chromatid cohesion is lost at the metaphase-to-anaphase transition, so that sister chromatids can disjoin. In meiosis, two chromosome segregations follow a single round of DNA-replication, and this is possible because cohesion is released in two steps (reviewed by Nasmyth 2001Nasmyth , 2005.Cohesins not only provide sister chromatid cohesion, but also participate in homologous recombination, both in the mitotic cycle and in meiosis. In mitosis, they enhance sister chromatid-based recombinational repair. In meiosis, their role is modified in such a way that homologous recombination occurs preferentially between chromatids of homologs, in most species, mainly or exclusively by a TF-dependent pathway of crossing over (reviewed by

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Untitled

Cited by 28 publications

References 47 publications

The Cancer Aneuploidy Paradox: In the Light of Evolution

The Cancer Aneuploidy Paradox: In the Light of Evolution

Isotope abundance analysis for improved sample identification with tandem mass spectrometry

The diverse roles of transverse filaments of synaptonemal complexes in meiosis

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