Structure of Hermes integrations in the germline of the yellow fever mosquito, Aedes aegypti

The Hermes transposable element is derived from the house fly, Musca domest ica, and can incorporate into the germline of the yellow fever mosquito, Ae des aegypti. Preliminary Southern analyses indicated that Hermes integrated along with the marker gene into the mosquito genomic DNA. Here we show tha t Hermes integrations are accompanied by the integration of the donor plasm id as well. In addition, breaks in the donor plasmid DNAs do not occur prec isely, or at the end of the terminal inverted repeats, and are accompanied by small deletions in the plasmids. Furthermore, integrations do not cause the typical 8-bp duplications of the target site DNA. No integrations are o bserved in the absence of a source of Hermes transposase. The Hermes transp osase clearly did not catalyse precise cut-and-paste transposition in these transformed lines. It may have integrated the transposon through general r ecombination or through a partial replicative transposition mechanism. The imprecision of Hermes integration may result from interactions of the trans posase with an endogenous hAT-like element in the mosquito genome.