An Hsp83 promoter drives expression of 6 tandem repeats of a mutated 72bp fragment from roX2, which encodes the stem-loop region. Each repeat has a mutation in the GUb sequence of the 3' stem region. An Act5C fragment provides the polyA site.
roX2M-SL-6.Hsp83 shows no rescue of the lethality of roX[-] males (roX1ex6 Df(1)52 P{w+4Δ4.3}/Y).