STRUCTURAL VARIATION OF THE RIBOSOMAL GEN E-CLUSTER WITHIN THE INSECTA CLASS

General estimation of ribosomal DNA variation within the Insecta class is presented. It is shown that, using blot-hybridization, one can det ect differences in the structure of the ribosomal gene cluster not onl y between genera within an order, but also between species within a ge nera, including sibling species. Structure of the ribosomal gene clust er of the Coccinelidae family (ladybirds) is analyzed. It is shown tha t cloned highly conservative regions of ribosomal DNA of Tetrahymena p yriformis can be used as probes for analyzing ribosomal genes in insec ts.