A diagram of the P{wHy} element is available at the [GDP Transposons page](http://flypush.imgen.bcm.tmc.edu/pscreen/transposons.html)

The P{wHy} transgene is a "double" transposable element that consists of: P-element 5' end - w^+mC marker - a hobo element (oriented 5' to 3') - y^+t7.7 marker - P-element 3' end. P{wHy} is designed to exploit the local transpositional and recombinatorial properties of the hobo element to generate chromosomal deletions; in the presence of a source of hobo\T transposase, local transposition of the hobo element in P{wHy}, followed by recombination between the original and newly inserted hobo elements, results in efficient generation of deletions with one endpoint at the site of the original P{wHy} insertion. The presence of the two different markers either side of the original hobo element allows for the directional detection of deletion events.