Sequence heterogeneity in radish nuclear ribosomal RNA genes

Abstract

The organization of nuclear rRNA genes from radish was studied. Two Bam HI fragments were cloned and used as probes in hybridization experiments. These experiments allowed to establish restriction maps for Bam HI and EcoRI sites and to demonstrate a sequence heterogeneity: two Bam HI sites are not constant and several EcoRI patterns differing by gain or loss of a site coexist. Experiments with single plants demonstrate that the observed heterogeneity is at the level of the individuals rather than the population.