Contains a gypsy element at -700bp and a chimeric element at -69bp relative to the transcription start site. In the chimeric element, a 19.7kb sequence combined from three different X-chromosomal regions is flanked by two identical copies of a defective 1.2kb P-element which are oriented in the same way.
22.1kb insertion 69bp upstream of the y transcription start site. y sequences from -146bp to -70bp are also deleted. The insertion contains a central region of 19.7kb genomic DNA flanked by two identical copies of a 1.2kb deleted P-element (nucleotides 830 to 2430 have been deleted and are replaced by a 10bp sequence), which are arranged in the same orientation. The direction of transcription of the P-elements is opposite to that of the y gene. Neither the whole insertion nor the individual P-elements are flanked by the characteristic base pair duplications that are normally found after P-element insertion. The 19.7kb genomic fragment that is flanked by the P-elements includes sequences from two, or possibly three, different regions of the X chromosome and some repetitive sequences. The gypsy element present in the progenitor y2 allele is still present.