Homology of the 3 ' terminal sequences of the 18S rRNA of Bombyx mori and the 16S rRNA of Escherichia coli

The terminal 220 base pairs (bp) of the gene for 18S rRNA and 18 bp of the adjoining spacer rDNA of the silkworm Bombyx mori have been sequenced. Comparison with the sequence of the 16S rRNA gene of Escherichia coli has shown that a region including 45 bp of the J3. mori sequence at the 3 ' end is remarkably homologous with the 3 ' terminal _E. coli sequence. Other homologies occur in the terminal regions of the 18S and 16S rRNAs, includ-ing a perfectly conserved stretch of 13 bp within a longer homology located 150-200 bp from the 3 ' termini. These homologies are the most extensive so far reported between prokaryotic and eukaryotic genomlc DNA