Changes in the Amount of DNA in Cell Nuclei during Vertebrate Evolution

Szarski, Henryk

doi:10.1038/226651a0

Cited by 69 publications

(27 citation statements)

References 13 publications

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“…Several investigators have speculated about an adaptive value of the observed increase in genome and cell size in amphibians and lungfishes (Szarski 1970;Chipman et al 2001;Chipman 2002;Vinogradov 2004). Forexample, Szarski (1970Szarski ( , 1983 suggested that these changes can be viewed as an adaptation to life in cold climates (cf.…”

Section: Evolutionary Considerationsmentioning

confidence: 99%

“…In amphibians, as well as in some other groups of vertebrates, genome size determines cell size (i.e., volume) by the fact that large amounts of DNA appear to require large nuclei and, consequently, large cell volumes (Ohno 1970;Szarski 1970Szarski , 1983Olmo andMorescalchi 1975, 1978;Vinogradov 2004;Gregory 2005a). In salamanders, average cell size varies from 7.2 mm in diameter in Desmognathus ochrophaeus to 15.1 mm in Hydromantes genei.…”

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confidence: 99%

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The Influence of Genome and Cell Size on Brain Morphology in Amphibians

Roth

Walkowiak

2015

Cold Spring Harb Perspect Biol

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In amphibians, nerve cell size is highly correlated with genome size, and increases in genome and cell size cause a retardation of the rate of development of nervous (as well as nonnervous) tissue leading to secondary simplification. This yields an inverse relationship between genome and cell size on the one hand and morphological complexity of the tectum mesencephali as the main visual center, the size of the torus semicircularis as the main auditory center, the size of the amphibian papilla as an important peripheral auditory structure, and the size of the cerebellum as a major sensorimotor center. Nervous structures developing later (e.g., torus and cerebellum) are more affected by secondary simplification than those that develop earlier (e.g., the tectum). This effect is more prominent in salamanders and caecilians than in frogs owing to larger genome and cells sizes in the former two taxa. We hypothesize that because of intragenomic evolutionary processes, important differences in brain morphology can arise independently of specific environmental selection.

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Section: Evolutionary Considerationsmentioning

confidence: 99%

mentioning

confidence: 99%

The Influence of Genome and Cell Size on Brain Morphology in Amphibians

Roth

Walkowiak

2015

Cold Spring Harb Perspect Biol

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“…In terms of metabolic rate, erythrocyte size-or more specifically, surface area:volume (SA:V) ratio-is believed to exert the predominant influence (e.g., Szarski 1970Szarski , 1983. Thus, Szarski (1983) envisioned a continuum of wasteful and frugal evolutionary strategies along which cell and genome sizes are reduced or expanded according to each organism's physiological requirements.…”

Section: C-value Constraints In Birdsmentioning

confidence: 99%

“…As an extreme example, ''birds have the highest metabolism accompanied by the smallest cell size and by the smallest amount of DNA per nucleus'' (Szarski 1970, p. 652). Many general discussions of the nature and importance of the relationship between genome size and erythrocyte volume have emerged since that time (e.g., Cavalier-Smith 1978, 1991Szarski 1970Szarski , 1976Szarski , 1983Olmo 1983;Gregory 2001a). As related to homeotherms, Cavalier-Smith (1985, p. 128) suggests that ''strong stabilizing selection for optimal red cell volume is a major selective force that maintains a relatively uniform cell volume in mammals and birds (and secondarily causes the uniformity in C-values).''…”

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A Bird's-Eye View of the C-Value Enigma: Genome Size, Cell Size, and Metabolic Rate in the Class Aves

Gregory¹

2002

Evolution

217

178

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Abstract. For half a century, variation in genome size (C-value) has been an unresolved puzzle in evolutionary biology. While the initial ''C-value paradox'' was solved with the discovery of noncoding DNA, a much more complex ''C-value enigma'' remains. The present study focuses on one aspect of this puzzle, namely the small genome sizes of birds. Significant negative correlations are reported between resting metabolic rate and both C-value and erythrocyte size. Cell size is positively correlated with both nucleus size and C-value in birds, as in other vertebrates. These findings shed light on the constraints acting on genome size in birds and illustrate the importance of interactions among various levels of the biological hierarchy, ranging from the subchromosomal to the ecological. Following from a discussion of the mechanistic bases of the correlations reported and the processes by which birds achieved and/or maintain small genomes, a pluralistic approach to the C-value enigma is recommended.

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“…Although the costs of producing copies of a bigger genome are obvious, these costs may not be high enough to balance mutation pressure for selfish (parasitic) DNA accumulation. A strong correlation between C-value and cell size exists, however (2,5). Within a taxon, smaller cells usually divide faster and have a higher metabolic rate, as evidenced by the strong negative correlation between specific metabolic rates corrected for body size and DNA amounts in mammals (6) and birds (7,8), and by direct measures of erythrocyte metabolism in amphibians (9).…”

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confidence: 99%

Cell size as a link between noncoding DNA and metabolic rate scaling

Kozłowski

Konarzewski

Gawelczyk

2003

Proc. Natl. Acad. Sci. U.S.A.

304

382

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Accumulation of noncoding DNA and therefore genome size (Cvalue) may be under strong selection toward increase of body size accompanied by low metabolic costs. C-value directly affects cell size and specific metabolic rate indirectly. Body size can enlarge through increase of cell size and͞or cell number, with small cells having higher metabolic rates. We argue that scaling exponents of interspecific allometries of metabolic rates are by-products of evolutionary diversification of C-values within narrow taxonomic groups, which underlines the participation of cell size and cell number in body size optimization. This optimization leads to an inverse relation between slopes of interspecific allometries of metabolic rates and C-value. To test this prediction we extracted literature data on basal metabolic rate (BMR), body mass, and C-value of mammals and birds representing six and eight orders, respectively. Analysis of covariance revealed significant heterogeneity of the allometric slopes of BMR and C-value in both mammals and birds. As we predicted, the correlation between allometric exponents of BMR and C-value was negative and statistically significant among mammalian and avian orders.allometry ͉ genome size ͉ body size optimization ͉ cell number

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Changes in the Amount of DNA in Cell Nuclei during Vertebrate Evolution

Cited by 69 publications

References 13 publications

The Influence of Genome and Cell Size on Brain Morphology in Amphibians

The Influence of Genome and Cell Size on Brain Morphology in Amphibians

A Bird's-Eye View of the C-Value Enigma: Genome Size, Cell Size, and Metabolic Rate in the Class Aves

Cell size as a link between noncoding DNA and metabolic rate scaling

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