A roX1 cDNA with multiple nucleotide substitutions in the RB1 domain and deletion of both the RB2 and RB3 domains is cloned downstream of Hsp83 promoter sequences.
lncRNA:roX1-RB123.Hsp83 fails to rescue Df(1)52/lncRNA:roX1MB710
The presence of roX1ΔRB123.Hsp83 fails to rescue roX1MB710 Df(1)52 male viability to wild-type levels.