title: Conservative genome size and rapid chromosomal evolution in the South American tuco-tucos (Rodentia: Ctenomyidae).
abstract: Genome size (the amount of DNA per cell) was measured by flow-cytometric analysis in seven species of a chromosomally variable rodent genus: Ctenomys boliviensis, C. conoveri, C. frater, C. leucodon, C. lewisi, C. opimus, and C. steinbachi. The mean genome size of these species was 7.19 pg DNA and little inter- and intra-specific variation was observed. Genome size was not correlated with diploid number, suggesting that chromosomal evolution at this level is independent of total DNA content. A hypothetical taxonomic unit optimization procedure was carried out using genome size change on a Wagner tree derived from allozyme data. Allozyme evolution and genome size change are linked by a weak, but significant, negative correlation suggestive of preferential genic evolution in the absence of genome size evolution.
authors.affiliation: Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station 77843-2258.
authors.forename: L A
authors.initials: LA
authors.lastname: Ruedas
authors.forename: J A
authors.initials: JA
authors.lastname: Cook
authors.forename: T L
authors.initials: TL
authors.lastname: Yates
authors.forename: J W
authors.initials: JW
authors.lastname: Bickham
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001838:Bolivia; D002875:Chromosomes; D004247:DNA / Q000032:analysis / Q000235:genetics; D014644:Genetic Variation; D016678:Genome; D010802:Phylogeny; D012377:Rodentia / Q000235:genetics*; D013045:Species Specificity
chemical_list: D004247:DNA