UAS sequences regulate expression of the R2H1 region of lncRNA:roX2 (a high affinity contact point for the mle protein) fused to a lncRNA:roX2 fragment that contains the ASL and R2H5 regions. 10 nucleotides at the right stem of R2H5 have been mutated (this is predicted to prevent the formation of R2H5 and lead to constitutive ASL formation).
