Hepatoma-derived growth factor-related protein (HRP)-1 gene in spermatogenesis in mice

Hepatoma-derived growth factor (HDGF)-related protein (HRP)-1, a member of the HDGF gene family, showed testis-specific expression in mice. HRP-1 expression in spermatogenesis was analyzed in the testis of normal and azoospermic mice by Northern blot and immunohistochemistry. HRP-1 gene message was not expressed in the ovary and its product was detected only in the nuclei of germ cells, not in somatic cells. The HRP-1 gene is expressed through pachytene spermatocyte to round spermatid. HRP-1 gene expression was not detected in the testis of cryptorchid mice or in some strains of mutant mice. These findings suggest that the testis-specific HRP-1 gene may play an important role in the phase around meiotic cell division.