Variant Hepatocyte Nuclear Factor 1 expression in the mouse genital tract

Variant Hepatocyte Nuclear Factor 1 (vHNF1/HNF1 beta) is a homeodomain-cont aining transcription factor first expressed in the primitive endoderm and i ts derivatives, the visceral and parietal endoderm. It is subsequently expr essed in epithelial cells of different organs, including the primitive gut and derivatives (liver, pancreas, lung), the kidney, and transiently, in th e neural tube. We report here new data concerning vHnf1 expression in the m ouse genital tract, using both RNA analyses and our vHnf1 heterozygous muta nt mouse line, in which the first coding exon of the vHnf1 gene is replaced by the NSLacZ reporter gene. Both beta -galactosidase activity and vHnf1 t ranscripts are detected in epididymus, vas deferens, seminal vesicle, prost ate, uterus and oviduct. RNA analysis and in situ hybridization studies dem onstrate that vHnf1 transcripts are restricted to the germinal cells of the testis. Unexpectedly, no beta -galactosidase activity is detected in the t estis. We further show that, in addition to the somatic transcript, two mor e abundant vHnf1 transcript variants, which lack exons 1-4, appear in this organ after meiosis. (C) 2001 Elsevier Science Ireland Ltd. All rights rese rved.