gene encodes a protein with 3 C2H2 double zinc finger domains of the SAL-type, the second of which has a single C2H2 zinc finger attached at its C-terminal end, as well as an N-terminal C2HC zinc finger motif typical for vertebrate SAL-like proteins. By Northern blot analysis, they detected expression of a 5.5-kb SALL4 transcript exclusively in adult testis. RT-PCR confirmed expression in adult testis and revealed faint SALL4 expression in ovary and spleen.Northern blot analysis of adult mouse tissues detected a 5.0- to 5.5-kb transcript only in testis and ovary. In situ hybridization revealed widespread Sall4 expression in early mouse embryos. Expression was gradually confined to the head region and the primitive streak, and later there was prominent expression in the developing midbrain, branchial arches, limbs, and genital papilla.