Interspersion of repetitive with repetitive sequences in an amphibian, Rana berlandieri.

When conventional genome arrangement analyses performed on R. berlandieri DNA at a normal (60 degrees C) and a high (75 degrees C) reassociation temperature were compared, an additional interspersion pattern was detected which indicates that different classes of repetitive sequences are closely interspersed with each other. Our results further suggest that the genomic abundance of purified (or cloned) repetitive sequences can be accurately determined by solution hybridization with genomic DNA only when the reassociation is performed at a relatively high temperature (Tm - 10 degrees C).