The progenitor of this allele (a y2s mutation) has a 1.2kb P-element inserted 69bp upstream of the y transcription start site, together with deletion of y sequence from -146bp to -70bp. The P-element is transcribed in the opposite orientation to that of the y gene. The progenitor also contains the gypsy insertion of y2. y+s2 results from the deletion of sequences distal to the P-element, including part of the gypsy sequence (up to position 1054 - coordinates according to FBrf0045014) that contains 11 out of the 12 su(Hw) protein binding sites.
Revertant.