The following information accompanied stocks donated to the Bloomington Stock Center by Victoria Meller, Wayne State University.
P{RS5}G9a5-HA-2731 is an insertion in the X portion of Dp(1;Y)y+ rather than a normal X chromosome. It was isolated in the screen described in Ryder et al. (http://flybase.org/reports/FBrf0179424.html) where males in which P transposition occurred usually carried Dp(1;Y) rather than a normal Y chromosome.
P{RS5r}G9a5-HA-2731 is a derivative of P{RS5}G9a5-HA-2731 in which the FRT cassette was removed by FLP-mediated recombination.