GENES CODING RIBOSOMAL PROTEIN RPL11 AND 5,8S RIBOSOMAL RNA IN SPECIES OF GENUS CHIRONOMUS: NUCLEOTIDE VARIABILITY, DIVERGENCE AND CHROMOSOMAL LOCATION.

Ribosomes of eukaryotic cells contain four rRNA’s (28S, 18S, 5,8S and 5S) and about 80 ribosomal proteins (RP). Whereas the patterns of evolution and chromosomal location of rRNA genes are studied rather extensively in many taxonomic groups, there is only scarce information about evolution of genes coding ribosomal proteins. To obtain more information about evolution of ribosomal protein genes, the study of the nucleotide sequences and chromosomal location of rp111 gene was carried out in 12 species of the genus Chironomus. Characteristics of intra- and interspecific variability of this gene have been obtained and a high percenatage of identity has been shown between nucleotide sequences of different species from the Chironomus. FISH analysis has shown that ribosomal protein gene rp111 is located in a single site (region 25f), near centromere of the arm B. No variations in the number of sites and chromosomal position of the gene were observed in the karyotypes of the studied chironomid species indicating the evolutionary conservation of the chromosomal region where rp111 is located. We have established that the number and location of rp111 gene in chromosomal karyotypes of studied chironomid species do not coincide with the number and positions of 5,8S rRNA gene. The data obtained allow to conclude that the evolution of nucleotide sequences and chromosomal location of rp111 and 5,8S rRNA genes in genomes of Chironomus species occurred independently.