CHARACTERIZATION OF APHIDIUS-ERVI (HYMENOPTERA, BRACONIDAE) RIBOSOMALGENES AND IDENTIFICATION OF SITE-SPECIFIC INSERTION ELEMENTS BELONGING TO THE NON-LTR RETROTRANSPOSON FAMILY

We performed a molecular analysis of the Aphidius ervi ribosomal gene structure. This insect belongs to a set of closely related Aphidiinae species of the genus Aphidius Nees, of relevant interest in biological control. We constructed A. ervi genomic libraries, cloned and charact erized several rDNA repeating units and sequenced different regions of the rDNA cistrons. We have found that insertion sequences interrupt t he A. ervi 28S rDNA genes: the sequences of the two 5' and 3' insertio n-28S junctions show that the elements are present at the position whe re R1 elements have been found in various insect species. In addition, the insertion of the element produces a duplication of the 14 nt targ et region. The sequence analysis indicates that the A. ervi elements b elong to the R1 retrotransposon family with a highly conserved reverse transcriptase domain.