An evolutionarily conserved domain of roX2 RNA is sufficient for induction of H4-Lys16 acetylation on the Drosophila X chromosome.

The male-specific lethal (MSL) complex, which includes two noncoding RNA on X (roX)1 and roX2 RNAs, induces histone H4-Lys16 acetylation for twofold hypertranscription of the male X chromosome in Drosophila melanogaster. To characterize the role of roX RNAs in this process, we have identified evolutionarily conserved functional domains of roX RNAs in several Drosophila species (eight for roX1 and nine for roX2). Despite low homology between them, male-specific expression and X chromosome-specific binding are conserved.