[Determination of the degree of ribosomal genes conservativity in some invertebrate species].

DNA-RNA hybridization was used to determine the degree of similarity of ribosomal genes in some invertebrate species. The degree of similarity of the nucleotide sequences of the ribosomal genes in various classes of Echinodermata appeared to be the same as in different invertebrate types. The base sequence mismatch in hybrid rRNA-DNA molecules did not exceed 10%, even when species from different invertebrate types were compared. The results obtained suggest that the changes in common rRNA structures occurred at a very low rate in the course of a long time period (more than 600 million years).