DNA insertions as a component of the evolution of unique satellite DNA families in two genera of parasitoid wasps: Diadromus and Eupelmus (Hymenoptera)

In the two parasitoid wasps, Diadromus collaris and Eupelmus orientalis,the satellite DNAs were each found to consist wholly or largely of a singlefamily (5%-7% of the genome). Several clones of each family were obtainedand sequenced. The repeat unit in each species is characterized by both therepetition of a basic motif and the presence of an inserted sequence.Sequence comparisons with satellite DNA from D. pulchellus and E. vuilletiprovide plausible scenarios for the evolution of the satellite DNA in eachgenus. Palindromes and A-rich tracts in each consensus sequence suggest theformation, in vivo, of hairpin structures and bend centers that may play arole in heterochromatin condensation in insects. The insertions in therepeat units of each species also contain these structural features,suggesting that maintenance of these insertions requires constraintssimilar to those pertaining to the rest of the satellite- DNA unit.