title: The C-value enigma in plants and animals: a review of parallels and an appeal for partnership.
abstract: OBJECTIVE
  Plants and animals represent the first two kingdoms recognized, and remain the two best-studied groups in terms of nuclear DNA content variation. Unfortunately, the traditional chasm between botanists and zoologists has done much to prevent an integrated approach to resolving the C-value enigma, the long-standing puzzle surrounding the evolution of genome size. This grand division is both unnecessary and counterproductive, and the present review aims to illustrate the numerous links between the patterns and processes found in plants and animals so that a stronger unity can be developed in the future.
  
  
  METHODS
  This review discusses the numerous parallels that exist in genome size evolution between plants and animals, including (i) the construction of large databases, (ii) the patterns of DNA content variation among taxa, (iii) the cytological, morphological, physiological and evolutionary impacts of genome size, (iv) the mechanisms by which genomes change in size, and (v) the development of new methodologies for estimating DNA contents.
  
  
  CONCLUSIONS
  The fundamental questions of the C-value enigma clearly transcend taxonomic boundaries, and increased communication is therefore urged among those who study genome size evolution, whether in plants, animals or other organisms.
authors.affiliation: Department of Entomology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK. rgregory@genomesize.com
authors.forename: T Ryan
authors.initials: TR
authors.lastname: Gregory
mesh_terms: D000818:Animals; D048429:Cell Size; D004247:DNA / Q000032:analysis / Q000235:genetics; D030541:Databases, Genetic; D016678:Genome; D018745:Genome, Plant; D010944:Plants / Q000145:classification / Q000235:genetics*; D011123:Polyploidy; D013045:Species Specificity
chemical_list: D004247:DNA