An Hsp83 promoter drives expression of 6 tandem repeats of a wild-type 72bp fragment from roX2, which encodes the stem-loop region. An Act5C fragment provides the polyA site.
roX2W-SL-6.Hsp83 shows a low frequency of rescue (17%) of the lethality of roX[-] males (roX1ex6 Df(1)52 P{w+4Δ4.3}/Y).