A 2.9kb genomic fragment flanked by two copies of a 1.2kb deleted P-element, which are arranged in opposite orientations, has been inserted 69bp upstream of the y transcription start site. The transposed 2.9kb fragment contains sequences that originate from region 1A of the X chromosome in close proximity and distal to the y locus, and some repetitive sequences. The fragment also contains anon-1Ab.