Mobilization of a Drosophila transposon in the Caenorhabditis elegans germline

Transposons have been enormously useful for genetic analysis in both Drosop hila and bacteria. Mutagenic insertions constitute molecular tags that are used to rapidly clone the mutated gene. Such techniques would be especially advantageous in the nematode Caenorhabditis elegans, as the entire sequenc e of the genome has been determined. Several different types of endogenous transposons are present in C. elegans, and these can be mobilized in mutato r strains (reviewed in ref. 1). Unfortunately, use of these native transpos ons for regulated transposition in C. elegans is limited. First, all strain s contain multiple copies of these transposons and thus new insertions do n ot provide unique tags. Second, mutator strains tend to activate the transp osition of several classes of transposons, so that the type of transposon a ssociated with a particular mutation is not known. Here we demonstrate that the Drosophila mariner element Mos1 can be mobilized in C. elegans. First, efficient mobilization of Mos1 is possible in somatic cells. Second, herit able insertions of the transposon can be generated in the germ line. Third, genes that have been mutated by insertion can be rapidly identified using inverse polymerase chain reaction. Fourth, these insertions can subsequentl y be remobilized to generate deletion and frameshift mutations by imperfect excision.