Karyotypic Variability in Ribosomal DNA Subchromosome Size among Colpodid Ciliates, a Possible Tool To Differentiate Colpodid Species

Pulsed-field gel electrophoresis has been applied to analyze the karyotypic variability among colpodid ciliates. The 18S ribosomal gene was found at different locations in the electrophoretic pattern, and these size variations in the ribosomal DNA subchromosomal molecule seem to be species specific. This could potentially be a useful new tool with which to differentiate colpodid ciliates.