Variation in Genome Size in Benthic Polychaetes: Systematic and Ecological Relationships

Genome size (or C-value) in benthic polychaetes was studied from both experimental data and literature. Nuclear DNA content variation was analysed as related to both phylogenetic relationships of various families, general life habit of the species (interstitial vs macrobenthic), diploid chromosome number (2n), and mean body size (length). Experimental data on genome size were obtained for 43 lower taxa (genera and species) by means of microdensitometric analysis of the amount of Fuelgen-stained haploid DNA in interphase nuclei. These data, added to those available in the literature (36 taxa studied by Conner et al., 1972) gave a total of 79 taxa (genera and species), representing 30 families and 14 orders. Twenty-one of the species studied belonged exclusively to interstitial (=meiofaunal) families or genera.

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First estimates of genome size in ribbon worms (phylum Nemertea) using flow cytometry and Feulgen image analysis densitometry

Canadian Journal of Zoology ◽

10.1139/cjz-2014-0068 ◽

2014 ◽

Vol 92 (10) ◽

pp. 847-851 ◽

Cited By ~ 3

Author(s):

Kelly L. Mulligan ◽

Terra C. Hiebert ◽

Nicholas W. Jeffery ◽

T. Ryan Gregory

Keyword(s):

Flow Cytometry ◽

Image Analysis ◽

Body Size ◽

Genome Size ◽

Positive Relationship ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Size Estimation ◽

Size Diversity ◽

Size Estimates

Ribbon worms (phylum Nemertea) are among several animal groups that have been overlooked in past studies of genome-size diversity. Here, we report genome-size estimates for eight species of nemerteans, including representatives of the major lineages in the phylum. Genome sizes in these species ranged more than fivefold, and there was some indication of a positive relationship with body size. Somatic endopolyploidy also appears to be common in these animals. Importantly, this study demonstrates that both of the most common methods of genome-size estimation (flow cytometry and Feulgen image analysis densitometry) can be used to assess genome size in ribbon worms, thereby facilitating additional efforts to investigate patterns of variability in nuclear DNA content in this phylum.

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Nuclear DNA content variation and evolution in liverworts

Molecular Phylogenetics and Evolution ◽

10.1016/j.ympev.2013.04.008 ◽

2013 ◽

Vol 68 (3) ◽

pp. 619-627 ◽

Cited By ~ 20

Author(s):

Jillian D. Bainard ◽

Laura L. Forrest ◽

Bernard Goffinet ◽

Steven G. Newmaster

Keyword(s):

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Content Variation ◽

Dna Content Variation

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Genome size and karyotype evolution in Tradescantia section Cymbispatha (Commelinaceae)

Genome ◽

10.1139/g90-089 ◽

1990 ◽

Vol 33 (4) ◽

pp. 604-610 ◽

Cited By ~ 1

Author(s):

Ann Kenton ◽

Andrew Drakeford

Keyword(s):

Genome Size ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Central American ◽

South American ◽

Basic Genome ◽

C Value ◽

Robertsonian Fusions ◽

Karyotype Morphology ◽

Dna Reduction

Karyotype morphology and nuclear DNA content are compared in species of Tradescantia section Cymbispatha from North and South America. Comparison of DNA amounts confirms the polyploid ancestry previously suggested for several cytotypes and shows that basic genome size has been unaffected by the Robertsonian fusions constituting a major evolutionary change in this group. The 2C-values of Mexican tetraploids are double those of their Central American diploid relative Tradescantia gracillima. The 2C-value of the South American tetraploid T. cymbispatha is comparatively lower as a result of a reduction in the size of some chromosomes. This reduction is most likely to have been achieved by Robertsonian fusions in a hybrid whose parental chromosome sets differed in size. The results provide evidence for selection of ancestral diploids with low C-value as mechanism for reduction of genome size in polyploids.Key words: Tradescantia, genome size, polyploidy, Robertsonian fusion, DNA reduction.

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