Genome size of Eperythrozoon suis and hybridization with 16S rRNA gene

The genome size of Eperythrozoon suis, an unculturable haemotropic mycoplas ma, was estimated using pulsed-field gel electrophoresis (PFGE). Gamma irra diation was used to introduce one (on the average) double-strand break in t he E. suis Illinois chromosome. Restriction enzymes that cut infrequently w ere also used to analyze genome size. The size estimate for the full-length genome was 745 kilobases (kb), whereas the size estimates based on the sum mation of restriction fragments ranged from 730 to 770 kb. The 16S rRNA gen e was located on the 120-kb MluI fragment, 128-kb NruI fragment, 25-kb SacI I fragment, and 217-kb SalI fragment by Southern blotting.