Acts synergistically with sop-2 to maintain the transcriptionally repressive state of homeotic genes throughout development. Not required to initiate repression, but to maintain it during later stages of development. Also required to repress expression of other genes. Binds RNA in a sequence-independent manner. Binds through its N-terminal region to the N-terminal region of sop-2. Forms subnuclear bodies. Sop-2 is required for nuclear localization. Expressed at all developmental stages with levels declining as development proceeds. Worms exhibit early larval lethality and anterior to posterior cell fate transformation in a Hox gene-dependent manner. Hermaphrodites show vulva defects, partial hermaphrodite-to-male sexual transformation and are sterile.