An Hsp83 promoter drives expression of a 3.4kb EcoRI fragment containing lncRNA:roX1 cDNA clone c20 in the antisense orientation (a 470bp PstI fragment from the tra2 gene is also present to provide a 3' poly-A site).
roX1ex6 Df(1)52/Y males carrying P{w+4Δ4.3} generally do not survive to adulthood. This lethality is not substantially rescued by an autosomal copy of roX1a.Hsp83.