Evidence for Chromosome Endoreduplication in Eudorina californica, a Colonial Alga

Tautvydas, Kestutis J.

doi:10.1111/j.1432-0436.1976.tb00889.x

Cited by 17 publications

(10 citation statements)

References 19 publications

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“…Similarly, as the land-slug Limax grows over its lifetime, it increases the size of the neurons within its brain through endoreduplication (Yamagishi et al 2011). A very tight relationship has been shown between DNA content and cell size in the green algae, Eudorina (Tautvydas 1976). The filamentous yeast, Ashbya , also contains many copies of its genome within a single cytoplasm.…”

Section: Cell Size Correlates With Dna Contentmentioning

confidence: 99%

Cell-Size Control

Amodeo

Skotheim

2015

Cold Spring Harb Perspect Biol

163

159

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Cells of a given type maintain a characteristic cell size to function efficiently in their ecological or organismal context. They achieve this through the regulation of growth rates or by actively sensing size and coupling this signal to cell division. We focus this review on potential size-sensing mechanisms, including geometric, external cue, and titration mechanisms. Mechanisms that titrate proteins against DNA are of particular interest because they are consistent with the robust correlation of DNA content and cell size. We review the literature, which suggests that titration mechanisms may underlie cell-size sensing in Xenopus embryos, budding yeast, and Escherichia coli, whereas alternative mechanisms may function in fission yeast.

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Section: Cell Size Correlates With Dna Contentmentioning

confidence: 99%

Cell-Size Control

Amodeo

Skotheim

2015

Cold Spring Harb Perspect Biol

163

159

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“…Secondly, there are certain species or genera whose members normally possess no endopolyploid cells, though in certain circumstances (environmental and varietal differences) it is possible for the endopolyploid condition to be expressed (Hesse, 1973;Evans and Van't Hof, 1975;Nagl and Capesius, 1976). Thirdly, there are instances where endopolyploid nuclei enter division, either spontaneously as part of a developmental sequence (Grell, 1946;Tautvydas, 1976), or after experimental treatment; these must be instances of the breakdown of a positive control of the endopolyploid condition. Fourthly, with regard to the genetic control of endopolyploidy, genes are known in Drosophila that determine the coordination between chromosome reduplication and cell division (Gloor and Staiger, 1954) and also the degree of chromosome replication and differentiation in endopolyploid nuclei (King and Burnett, 1957).…”

Section: Origin and Structurementioning

confidence: 99%

“…Another interesting example of the relationship of endopolyploidy and the economy and differentiation of cell functions is found in the colonial alga Eudorina. The endopolyploid gonidia that lie within the colony undergo some type of reduction division and give rise to as many cells as make up a new colony (Tautvydas, 1976). Here, the generation of new colonies and cell diversification are accomplished by the endopolyploid condition.…”

Section: Stratagematic Aspectsmentioning

confidence: 99%

Endopolyploidy: Towards an understanding of its biological significance

Barlow

1978

Acta Biotheor

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There is a certain measure of perplexity concerning the significance of endopolyploidy. It seems that this results from a narrow frame of reference from which investigators view the phenomenon; that is, a predilection for emphasizing the specialized functional aspect of endopolyploidy as it operates in species at the present time overrides any consideration of the rblethat this state may play in the life of a species in its encounter with the forces of natural selection either in the past or in the future.There does not seem to be any obvious relationship between the degree of endopolyploidy that a species can exhibit and either its basic DNA content or the structure of its nucleus. The significance of endopolyploidy may reside not so much in any specialized function that the condition can support,.but rather in the properties that are consequent upon tlie endopolyploid condition itself and which are distinct from those that apply to diploid cells. Some of the properties of the endopolyploid state, and examples of their manifestation in plants and animals, are discussed. The conclusion is that these properties have a potential that opens possibilities for new paths of development and serves as a factor upon which natural selection fan operate.Glaubst du nun, dat~ er hier Warheit redete? Warum glaubst du das? . . . Ich bin yon heute und ehedem, sagte er dann; abet etwas ist in mir, das yon morgen und ~bermorgen und einstmals.

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“…Among the ancestral, diploid eukaryotes, microsporidia from molecular data: "---emerged earlier than any other protistan groups" [9], and together with red algae showed endo-polyploid genome reductive behavior to haploidy. But, an example is first presented for high level "endoreduplicated genomes" undergoing depolyploidization that would be difficult to disqualify, because of careful quantitative DNA-analyses [48]. It is from the colonic alga Eudorina californica (family, Volvocaceae) with closed nuclear divisions, where in vegetative reproduction the conidial cells re-replicated their genomes 64 times the haploid genome.…”

Section: ) Reductive Endopolyploidy Creating a Cancerous Potentialmentioning

confidence: 99%

“…But interestingly, before leaving endo-polyploid reductive division it should be known that Eudorina (Volvocaceae family) showed division-behavior supporting an evolvement from the Chlamydomona alga, which interpretively performed "meiotic", two-step reduction-division of tetraploid cells in the absence of an intervening DNA-synthetic period [16] [17] [48]. These divisions with available cytology can equally well be from reductive endopolyploidy, which is supported from more detailed chromosomal analyses of the unicellular radiolaren Aulachanta scolymantha [9] [52].…”

Section: ) Reductive Endopolyploidy Creating a Cancerous Potentialmentioning

confidence: 99%

Neoplastic-Like CELL Changes of Normal Fibroblast Cells Associated with Evolutionary Conserved Maternal and Paternal Genomic Autonomous Behavior (Gonomery)

Walen¹

2014

JCT

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The present comparative review discusses conservation of early evolutionary, relic genetics in the genome of man, which determine two different mechanistic reductive division systems expressed by normal, human diploid cells. The divisions were orderly and segregated genomes reductively to near-diploid daughter cells, which showed gain of a proliferative advantage (GPA) over cells of origin. This fact of GPA expression is a fundamental requirement for initiation of tumorigenesis. The division systems were responses to a carcinogen-free induction system, consisting of short (1 -3 days) exposures of young cells to nutritional deprivation of amino acid glutamine (AAD). In recovery growth (2 -4 days) endo-tetra/ochtoploid cells and normal diploid metaphase cells demonstrated chromosomal reductive divisions to respectively heterozygous and homozygous altered daughter cells. Both division systems showed co-segregating whole complements, which for reduction of the diploid metaphases could only arise from gonomeric-based autonomous behavior of maternal and paternal (mat/pat) genomes. The timely associated appearance with these latter divisions was fast growing small-cells (1/2 volume-size reduced from normal diploidy), which became homozygous from haploid, genomic doubling. Both reductive divisions thus produced genome altered progeny cells with GPA, which was associated with pre-cancer-like cell-phenotypic changes. Since both "undesirable" reductive divisions expressed orderly division sequences, their genetic controls were assumed to be "old genetics", evolutionarily conserved in the genome of man. Support for this idea was a search for evidential material in the evolutionary record from primeval time, when haploid organisms were established. The theory was that endopolyploid and gonomery-based reductive divisions relieved the early eukaryotic organisms from accidental, non-proliferative diploidy and polyploidy, bringing the organism back to vegetative haploid pro-liferation. Asexual cycles were common for maintenance of propagating haploid and diploid early unicellular eukaryotes. Reduction of accidental diploidy was referred to as "one-step meiosis" which meant gonomeric-based maternal and paternal genomic independent segregations. This interpretation was supported by exceptional chromosomal behaviors. However, multiple divisions expressing non-disjunction was the choice-explanation from evolutionists, which today is also suggested for the rarer LL-1 near haploid leukemia. These preserved non-mitotic mechanistic divisions systems are today witnessed in apomixes and parthenogenesis in many animal phyla. Thus, the indications are the modern genome of man harbors, relic-genetics from past "good" evolvements assuring "stable" proliferation of ancient, primitive eukaryotes, but with cancer-like effects for normal human cells.

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Evidence for Chromosome Endoreduplication in Eudorina californica, a Colonial Alga

Cited by 17 publications

References 19 publications

Cell-Size Control

Cell-Size Control

Endopolyploidy: Towards an understanding of its biological significance

Neoplastic-Like CELL Changes of Normal Fibroblast Cells Associated with Evolutionary Conserved Maternal and Paternal Genomic Autonomous Behavior (Gonomery)

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