Transcriptional activator. Interacts with promoter regions for tbx-8.9, tbx-9, elt-1, hnd-1, scrt-1, and vab-7 genes. Binds the sequence ATTTATGAC. Binds to the enhancer region of the hlh-1 gene promoter during embryonic body wall muscle development. Activates the gene for mab-5 in embryo development. Necessary for vab-7 expression in C blastomeres in the posterior of embryos. Required for posterior V6 neuroectoblast cell fate specification during postembryonic neurogenesis (patterning) which generates the characteristic ray lineage during male tail development. Binds to ced-3 promoter and activated expression which is crucial for tail-spike cell death. Has a role in E cell specification in endoderm development and body wall muscle development. Interacts with tir-1 and let-756. Localized to condensed chromosomes. Blastomeres. Embryo. Oocytes. Expressed both maternally and zygotically. Expression observed at the 4 cell embryo in posterior blastomeres. Detected in all descendants of EMS and P2 blastomeres. During gastrulation and morphogenesis expression is seen sporadically in all major cell lineages except the germ line. By heat shock. Embryos shows disorganization of cell types and lack specification. Loss of V6 rays development in male tail. C and D blastomere derived muscle. Fifth intron is thought to contain a regulatory element required for expression in postembryonic neuroblast V6 cells. 3'-UTR thought to inhibit self-translation in anterior blastomeres. Belongs to the Caudal homeobox family. Truncated N-terminus.