A first assessment of genome size diversity in Monogonont rotifers

This study provides the first analysis of genome size diversity in Monogonont rotifers. Measurements were made using flow cytometry, with Drosophila melanogaster and chicken erythrocytes as internal standards. Nuclear DNA content (“2C”— assuming diploid genomes) in eight different species of four different genera ranged almost fourfold, from 0.12 to 0.46 pg. A comparison with previously published values for Bdelloid rotifers suggested that the genomes of Monogononts are significantly smaller than those of Bdelloids. When compared to other Metazoans, Monogonont rotifers seem to have relatively small genomes. For instance, the C-values of the two species with the smallest genomes, Brachionus dimidiatus and Synchaeta pectinata, were only 0.06 and 0.085 pg, respectively. Various explanations for genome size diversity within Monogononta are discussed.