Duplication of part of the sequence that originates from region 1A of the X chromosome which is present between two internally deleted P-elements in the progenitor y+s allele. The duplicated sequence is also located between the two P-elements in the y2s2.P allele. Nucleotides 1-682 of the P{}y+sa element have been deleted.
Body colour: y2-like pigmentation in the wing and body cuticle.