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Chromosome Res (2011) 19:925938
DOI 10.1007/s10577-011-9248-x
A guided tour of large genome size in animals: what we know and where we are heading
France Dufresne & Nicholas Jeffery
Published online: 1 November 2011# Springer Science+Business Media B.V. 2011
Abstract The study of genome size diversity is an ever-expanding field that is highly relevant in todays world of rapid and efficient DNA sequencing. Animal genome sizes range from 0.02 to 132.83 pg but the majority of animal genomes are small, with the most of these genome sizes being less than 5 pg. Animals with large genomes (>10 pg) are scattered within some invertebrates, including the Platyhelminthes, crustaceans, and orthopterans, and also the vertebrates including the Actinopterygii, Chondrichthyes, and some amphibians. In this paper, we explore the connections between organismal phenotype, physiology, and ecology to genome size. We also discuss some of the molecular mechanisms of genome shrinkage and expansion obtained through comparative studies of species with full genome sequences and how this may apply to species with large genomes. As most animal species sequenced to date have been in the small range for genome size (especially invertebrates) due to sequencing costs and to difficulties
associated with large genome assemblies, an understanding of the structural composition of large genomes is still lacking. Studies using next-generation sequencing are being attempted for the first time in animals with larger genomes. Such analyses using low genome coverage are providing a glimpse of the composition of repetitive elements in animals with more complex genomes. These future studies will allow a better understanding of factors leading to genomic obesity in animals.
Keywords Genome size . cell size . large genomes . transposable element . next-generation sequencing
AbbreviationsTE Transposable elementsNGS Next generation sequencingLTR Long terminal repeat retrotransposon SINE Short interspersed repetitive elements LINE Long interspersed repetitive elements BES BAC end sequencespg Picogram
Responsible Editor: Ryan Gregory and Jillian Bainard.
F. Dufresne (*)
Dpartement de Biologie, Centre dtudes Nordiques, Universit du Qubec Rimouski,300 alle des Ursulines,Qubec G5L 3A1, Canadae-mail: [email protected]
N. JefferyDepartment of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
Introduction to large genome sizes in animals
Genome size (the haploid DNA content per cell or C-value) estimates are now available for approximately 5000 animal species representing nearly 7,000-fold variation within...