CELL SIZE, NUCLEAR SIZE AND DNA CONTENT RELATIONSHIPS IN <i>GOSSYPIUM</i>

Edwards, G. Allan; Endrizzi, J. E.

doi:10.1139/g75-024

Cited by 32 publications

(25 citation statements)

References 10 publications

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“…While published data suggest that the DNA content of G. gossypioides is similar to that of other D-genome cottons (Edwards and Endrizzi 1976;Bennett and Leitch 1995;H.J. Paterson and S. Johnston, unpubl.…”

Section: Dispersed Repeats In Cotton Genome Analysis Genome Research 485mentioning

confidence: 94%

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Dispersed Repetitive DNA Has Spread to New Genomes Since Polyploid Formation in Cotton

Zhao¹,

Yang²,

Hanson³

et al. 1998

Genome Res.

237

193

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Polyploid formation has played a major role in the evolution of many plant and animal genomes; however, surprisingly little is known regarding the subsequent evolution of DNA sequences that become newly united in a common nucleus. Of particular interest is the repetitive DNA fraction, which accounts for most nuclear DNA in higher plants and animals and which can be remarkably different, even in closely related taxa. In one recently formed polyploid, cotton (Gossypium barbadense L.; AD genome), 83 non-cross-hybridizing DNA clones contain dispersed repeats that are estimated to comprise about 24% of the nuclear DNA. Among these, 64 (77%) are largely restricted to diploid taxa containing the larger A genome and collectively account for about half of the difference in DNA content between Old World (A) and New World (D) diploid ancestors of cultivated AD tetraploid cotton. In tetraploid cotton, FISH analysis showed that some A-genome dispersed repeats appear to have spread to D-genome chromosomes. Such spread may also account for the finding that one, and only one, D-genome diploid cotton, Gossypium gossypioides, contains moderate levels of (otherwise) A-genome-specific repeats in addition to normal levels of D-genome repeats. The discovery of A-genome repeats in G. gossypioides adds genome-wide support to a suggestion previously based on evidence from only a single genetic locus that this species may be either the closest living descendant of the New World cotton ancestor, or an adulterated relic of polyploid formation. Spread of dispersed repeats in the early stages of polyploid formation may provide a tag to identify diploid progenitors of a polyploid. Although most repetitive clones do not correspond to known DNA sequences, 4 correspond to known transposons, most contain internal subrepeats, and at least 12 (including 2 of the possible transposons) hybridize to mRNAs expressed at readily discernible levels in cotton seedlings, implicating transposition as one possible mechanism of spread. Integration of molecular, phylogenetic, and cytogenetic analysis of dispersed repetitive DNA may shed new light on evolution of other polyploid genomes, as well as providing valuable landmarks for many aspects of genome analysis.[The sequence data described in this paper have been submitted to GenBank under accession nos. AF060571-AF060667 and U31112-U31113.]Dispersed repetitive DNA is a major component of higher eukaryotic genomes, implicated as a major contributor to variation in DNA content among organisms of similar complexity (Charlesworth et al. 1994). Many dispersed repetitive element families may be examples of selfish DNA (Doolittle and Sapienza 1980;Orgel and Crick 1980) that is free to propagate in genomes unless it impairs the fitness of the organism. Selective advantages conferred by some dispersed repetitive elements have been suggested, such as the recruitment of genes (Martignetti and Brosius 1993), repair of chromosomal breaks (Teng et al. 1996), or induction of favorable mutants (Zeyl et al. 1996).Dispersed rep...

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Section: Dispersed Repeats In Cotton Genome Analysis Genome Research 485mentioning

confidence: 94%

“…Paterson and S. Johnston, unpubl. ), and 0.8 for C genome and 0.7 for the G genome on the basis of ratios of DNA content in the respective diploids to that of the tetraploid (Edwards and Endrizzi 1976). Each replica slot blot was used only once.…”

Section: Figurementioning

confidence: 99%

Dispersed Repetitive DNA Has Spread to New Genomes Since Polyploid Formation in Cotton

Zhao¹,

Yang²,

Hanson³

et al. 1998

Genome Res.

237

193

View full text Add to dashboard Cite

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“…the interphase nucleus (Baetcke et al, 1967;Edwards & Endrizzi, 1975); cell area and volume (Lawrence, 1985); and chloroplast number per guard cell (Butterfass, 1983). For example.…”

Section: Dna C-value and Cell Sizementioning

confidence: 99%

Variation in Genomic Form in Plants and Its Ecological Implications

Bennett¹

1987

New Phytologist

350

198

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SUMMARYThe gross form of the nuclear genome varies greatly among plant species in both anatomy and genetic organization. Chromosome number (n) ranges from 2 to over 600, and ploidy from 1 to over 20. The amount of DNA in the unreplicated haplophase genome (the lC value) differs by more than 2500-fold among angiosperms. Although it has been questioned since the 1930s whether such variation is of adaptive significance and whether it is related, perhaps causally, with environmental factors, no direct or causal links have yet been found. However, variation in DNA C-value has far-reaching biological consequences and can be of considerable adaptive and hence ecological significance. Strikingly precise interspecific relationships exist between DNA C-value and many diverse phenotypic characters at the cellular level, and DNA can affect the phenotype in two ways, firstly by expression of its genie content and, secondly, by the biophysical effects of its mass and volume, the latter defined as nucleotypic effects. Nucleotypic variation in DNA C-value sets absolute limits to both the minimum size and mass of the basic unit of plant anatomy (i.e. the cell) and the minumuni time needed to produce a similar cell with newly synthesized organic molecules. Moreover, in complex multicellular vascular plants, such effects at successive cell cycles are additive, so that DNA C-value influences many characters, including growth rate, seed weight, minimum generation time and type of life-cycle. Thus, the nucleotype profoundly affects where, when and how plants grow. Selection for a particular genomic form acting on its spatial or temporal consequences may occur at various levels ranging from the cell to the whole organism and may operate throughout the life-cycle or at just one stage. DNA C-value is often indirectly related to environmental factors which determine time-limited environments via selection acting on the temporal phenotypic consequences of nucleotypic variation. However, in the case of radio-sensitivity, selection for a low DNA C-value may act directly on the nucleotype itself, as the size of the nuclear DNA target directly affects the ability of the plant to survive.Key words: Plant genomic form, DNA C-value, DNA amount, cytoecology, nucleotype. GENOMIC FORM -CONSTANCY AND VARIATIONMany great discoveries in biology this century have concerned the genome and its form -that the genetic material is DNA, that this has a double helical structure, that this form is important in semi-conservative replication and cell heredity, and that the genetic code is written as triplets of nucleotides. In these important respects, genomic form is the same in all eukaryotes. These discoveries emphasized aspects of constancy in genomic form, except for the nucleotide base sequences of genie DNA whose variation determines the phenotype. However, much cytological work also showed that the genome can vary greatly in both anatomy and genetic organization among taxa.This review is concerned with variation in aspects of gross genomic form in nuclei...

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“…Previous works show that DNA C-values positively correlate with volume and weight of chromosomes (Baetcke et al 1967;Pegington and Rees 1970;Bennett et al 1983;Anderson et al 1985;Rees et al 1996), nuclear size (Edwards and Endrizzi 1975), organic carbon in single cell (Sunderland and Mcleish 1961), the duration of the mitotic and meiosis cycle (Bennett 1971(Bennett , 1977Evans et al 1972), the minimum generation time (Bennett 1972), seed-bearing age, and seed dimension (Wakamiya et al 1993), and negatively correlate with the lowest average annual and monthly precipitation, the highest average monthly spring air temperature of the habitats of Pinus species (Wakamiya et al 1993), and the distributing altitudes of Dactylis glomerata natural populations (Reeves et al 1998). Rejmánek (1996) hypothesized that low nuclear DNA content (genome size) seems to be a result of selection for short minimum generation time and, therefore, may be associated with plant invasiveness.…”

Section: Introductionmentioning

confidence: 92%

Applying DNA C-values to evaluate invasiveness of angiosperms: validity and limitation

2009

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DNA C-values might be one of important indices in the evaluation of angiospermous invasiveness. To test this viewpoint, we compared DNA 1C-values and basic genome sizes in 3,676 angiosperms. The results suggest that: (1) the two nuclear values vary greatly among different groups, e.g., significantly higher in herbs than in trees, in monocots than in dicots, in perennials than in non-perennials; (2) the two nuclear values both have significant effects on plant invasiveness, especially in herbs, dicots, monocots, perennials, non-perennials, diploids, polyploids, Compositae, and Poaceae, while not significant in trees and Fabaceae. Similar to weeds, the two values in crops are low, which suggests that crops may commonly hold higher invasive potential; (3) to evaluate the invasiveness of a given species, the information about ploidy level is necessary, and for polyploids, basic genome sizes are more reliable. For the results suggest that the selection favors polyploids in weeds at least partly because of the downsizing of basic genome size along with polyploidization.

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CELL SIZE, NUCLEAR SIZE AND DNA CONTENT RELATIONSHIPS IN GOSSYPIUM

Cited by 32 publications

References 10 publications

Dispersed Repetitive DNA Has Spread to New Genomes Since Polyploid Formation in Cotton

Dispersed Repetitive DNA Has Spread to New Genomes Since Polyploid Formation in Cotton

Variation in Genomic Form in Plants and Its Ecological Implications

Applying DNA C-values to evaluate invasiveness of angiosperms: validity and limitation

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