cDNA cloning and characterization of PD1: A novel human testicular proteinwith different expressions in various testiculopathies

A novel human cDNA sequence has been isolated from human testis cDNA librar y. This sequence, named PD1, reveals an open reading frame encoding a prote in of 520 amino acids. A partial sequence similarity has been found with th e RBM gene involved in the regulation of human spermatogenesis. Northern bl ot analysis for PD1 mRNA from several human tissues demonstrated two distin ct transcripts of 2.7 (more abundant) and 4.0 kb and revealed that PD1 is e xpressed in testis and to a lesser extent also in spleen, thymus, and prost ate. Immunohistochemical analysis of human testis showed that this protein is detected in the cytoplasm of Sertoli cells. Antibodies against a rhPD1 f ragment were used for Western blot analysis, which confirmed the presence o f a 60-kDa molecule in crude extract of human testicular cells obtained fro m fine-needle aspiration and showed different patterns in various testiculo pathies, suggesting a role for such gene in human spermatogenesis. (C) 1999 Academic Press.