Genome size and GC-percent in vertebrates as determined by flow cytometry: The triangular relationship

Abstract

Genome size and GC‐percent were determined by means of a special method of DNA flow cytometry in 154 vertebrate species. For the total dataset, a highly significant positive correlation was found between both parameters. The overall distribution of points is not linear but triangular: a wide range of GC‐percent values is observed at the lower end of genome size range, whereas with an increase in genome size the lower limit for GC‐percent is elevated, gradually approaching the upper limit (about 46%). In teleost fishes, which occupy the lower part of genome size range, the negative relationship between both parameters was observed. Two positive linear relationships were found between mean genome size and GC‐percent of the main vertebrate groups (one includes fishes, amphibians, and mammals, the other consists of reptiles and birds, which show the higher GC‐percent for their genome sizes). Distribution of variance between taxonomic levels indicates that GC‐percent is more evolutionarily conservative than genome size in anamniotes. Anuran amphibians show the greatest part of genome size variability at the lower taxonomic levels as compared to other vertebrates (with no additional variance already above the genus level). The data obtained with different methods are compared. It is shown that the proposed method can provide useful data for studies on genome evolution and biodiversity. Cytometry 31:100–109, 1998. © 1998 Wiley‐Liss, Inc.

Global transcription analysis of immature avian erythrocytic progenitors: from self-renewal to differentiation

“…The G þ C content of the libraries was consistent with the known overall G þ C content in chicken genes (42.27%; Vinogradov, 1998). The amount of repeated ditags was increased in the Di library suggesting that a reduction in complexity could accompany the differentiation process.…”

Phylogenomics of nonavian reptiles and the structure of the ancestral amniote genome

“…Using a base composition model allowing for an inhomogeneous distribution of GC content among sequence reads, the estimated GC content (SI Fig. 5) for alligator and turtle agrees closely with estimates for these species based on buoyant density gradients and flow cytometry (16,17). There are no previously published estimates of Anolis genomewide GC content; our results are slightly lower than those reported for other lacertid lizards and in close agreement with estimates for viperid and colubrid snakes (16,17).…”

“…5) for alligator and turtle agrees closely with estimates for these species based on buoyant density gradients and flow cytometry (16,17). There are no previously published estimates of Anolis genomewide GC content; our results are slightly lower than those reported for other lacertid lizards and in close agreement with estimates for viperid and colubrid snakes (16,17). Alligator, turtle, and Anolis GC means are significantly higher than those for whole human and chicken genomes (5,10) and for in silico sampling of chicken and human BAC-end sequences (see Materials and Methods and SI Text).…”

Lack of correlation between AT frequency and genome size in higher plants and the effect of nonrandomness of base sequences on dye binding

“…The ratio of the complementary nucleic bases adenine and thymine (AT) and guanine and cytosine (GC) also differs (1). In animals, there is a tendency of larger genomes to have a higher GC frequency (2,3). A similar relation seems to exist in higher plants (2), but this assumption is based on the data of only six species, compiled from different sources (4,5).…”