Probable transcription factor. Involved in kidney development, acting synergistically with lhx1/lim-1 in pronephric morphogenesis during the tailbud stages (By similarity). Expression becomes spatially localized at mid-gastrula stages and is confined to the nervous system (midbrain, hindbrain, spinal cord), sensory organs (optic vesicle and stalk, otic vesicle), visceral arches, developing excretory system (pronephros, pronephric duct, rectal diverticulum, proctodaeum) and thyroid gland. Splicing does not appear to be tissue-specific and tissues displayed the same spectrum of splice variants. Splicing is temporally regulated. Isoform 5 is expressed both maternally and zygotically, whereas isoform 1, isoform 2, isoform 3 and isoform 4 are exclusively zygotic. Expression is highest in embryos from stage 12 on, with expression levels remaining constant throughout embryogenesis. By activin. Weakly by bFGF.