Reporter of HMS-Beagle element transposition. Contains a complete copy of the HMS-Beagle retrotransposon (flanked by P-element ends) with an EGFP reporter cassette inserted in the antisense direction into the 3' non-coding region of HMS-Beagle (insertion is between nucleotides 6198 and 6199). The EGFP sequence contains a disruptive intron that can be spliced during transcription of the retrotransposon, but not during transcription of EGFP. Thus, EGFP protein is only expressed after mobilization of the HMS-Beagle element in the reporter transgene, which generates a new copy of HMS-Beagle containing EGFP without the disrupting intron.