EXPRESSION OF NEUROPSIN MESSENGER-RNA IN THE MOUSE EMBRYO AND THE PREGNANT UTERUS

Neuropsin is a novel serine protease whose mRNA is expressed in the mo use central nervous system. We examined the expression of neuropsin mR NA during embryonic development using Northern and in situ hybridizati on in non-neural tissues. The pregnant uterus showed strong expression of neuropsin mRNA, whereas the nonpregnant uterus did not express thi s mRNA. Expression was first detected in the primary decidual zone at 5.5 days post coitum and was maximized at 10 days post coitum, decreas ing remarkably thereafter. During mouse organogenesis, neuropsin expre ssion was observed in the developing heart, lung, thymus, pituitary, c horoid plexus, and epithelial linings of the skin, oral cavity, tongue , esophagus, and forestomach. In adult mouse organs, neuropsin mRNA wa s expressed in epithelial tissues covered by keratinocytes with modera te density, whereas low expression was observed in lung, thymus, and s pleen. Neuropsin mRNA expression in developing organs and adult kerati nocytes suggests that neuropsin is associated with extracellular matri x modifications and cell migrations.