A novel zinc finger gene, designated NT fin12, belonging to the C2H2-Krüppel-type gene family was isolated from a newborn mouse testis cDNA library by using zinc finger consensus motif probes. Northern blot analyses showed that NT fin12 mRNA was expressed during the meiotic prophase of spermatogenesis and in embryogenesis. Transcripts were localized by in situ hybridization in spermatogonia and in early spermatocytes, and in testis cords in the genital ridge as well as in oocytes and follicle cells in the ovary. In midgestational embryos at 8.5-13.5 days postcoitum, transcripts were present in the neuroectoderm, and they were progressively restricted to peripheral ganglia derived from neural crest cells and neural placodes and to the motor nerve cells in the central nervous system. Taken together these results indicate that NT fin12 functions during germ cell development and also plays a role in the specification of a subpopulation of neuroectodermal cells. Genetic linkage analyses revealed that the NT fin12 locus mapped to the deletion region of the tw18 haplotype on mouse chromosome 17.