An Hsp83 promoter drives expression of a deleted form of the lncRNA:roX1 c20 cDNA, which lacks nucleotides corresponding to 3023-3083 of accession number AB051842.
roX1ex6 Df(1)52/Y males carrying P{w+4Δ4.3} generally do not survive to adulthood. This lethality is partly rescued by an autosomal copy of roX1ΔIR.Hsp83.