rDNA in Locusta migratoria is very variable: two introns and extensive restriction site polymorphisms in the spacer

Cloned ribosomal DNA (rDNA) of Locusta migratoria was analyzed by restriction site mapping and SI nuclease experiments. The repeat unit is 18 kb long. The nontranscribed spacer region (NTS) is very large (11 kb) and homogeneous in length, but many of the restriction sites are heterogeneous among the repeat units. Two introns of different length were found at different positions in the 28S gene. They are present in less than 5% of the genes.