A mouse homeo box gene is expressed in spermatocytes and embryos.

The MH-3 gene, which contains a homeo box that is expressed specifically in the adult testis, was identified and mapped to mouse chromosome 6. By means of in situ hybridization with adult testis sections and Northern blot hybridization with testis RNA from prepuberal mice and from Sl/Sld mutant mice, it was demonstrated that this gene is expressed in male germ cells during late meiosis. In the embryo, MH-3 transcripts were present at day 11.5 post coitum, a stage in mouse development when gonadal differentiation has not yet occurred. The MH-3 gene may have functions in spermatogenesis and embryogenesis.