MUTATIONS IN GENES <i>spn-E, piwi</i><sup><i>2</i></sup><i>, </i>AND aub, INFLUENCING SMALL RNA PRODUCTION, DO NOT INFLUENCE THE RATE OF MUTATIONS ASSOCIATED WITH A <i>hobo </i>INSERTION IN THE <i>yellow </i>GENE OF <i>DROSOPHILA MELANOGASTER</i>
Effects of mutations in the <i>spn-E, piwi</i><sup><i>2</i></sup><i>, </i>and <i>aub </i>genes of <i>Drosophila melanogaster, </i>involved in small RNA production, on the mutation frequency in the highly unstable <i>y+</i><sup><i>h</i></sup><i> </i>allele, formed by an insertion of a <i>hobo </i>copy in the regulatory region of the <i>yellow </i>gene were studied. Mutation frequencies were assessed by crossing males with the genotypes y+<sup>h</sup>; <i>piwi/Cy, y+</i><sup><i>h</i></sup><i>; piwi/piwi, y+</i><sup><i>h</i></sup><i>; </i>aub/Cy andy+<sup>h</sup>; <i>spn-E/TM3 </i>to females with linked X-chromosomes. The frequency of mutations in the <i>yellow </i>gene depended to a greater extent on the cross to the strain with linked X-chromosomes than on the presence of a mutation in the <i>spn-E, piwi</i><sup><i>2</i></sup><i>, </i>or <i>aub </i>genes. The locus-specific instability in<i>y+</i><sup><i>h</i></sup><i> </i>allele is the sum of <i>hobo </i>transpositions and recombination events involving the <i>hobo </i>from the regulatory region of <i>yellow. </i>It appears that either the mutations under study do not affect the activity of the <i>hobo </i>copy or recombinations between <i>hobos </i>are much more significant for the locus-specific instability in <i>yellow </i>than the transposition rate.