ACTIVE TRANSPOSITION IN ZEBRAFISH

We have identified a new family of Tc1-like transposons in the zebrafi sh, Danio rerio. The sequence of a candidate active transposon, deduce d from sample Tzf elements, shows limited resemblance to the previousl y described Tdr1 elements of zebrafish. Both the Tzf and the Tdr eleme nts are extremely abundant in zebrafish. We describe here a general st rategy for detecting transposition events in a complex genome and demo nstrate its utility by selectively monitoring hundreds of potentially active Tzf copies in the zebrafish genome against a background of othe r related elements. We have followed members of a zebrafish pedigree, using this two-dimensional transposon display strategy, to identify th e first examples of active transposition of such elements in vertebrat es.