Expression and localization of the novel and highly conserved gametocyte-specific factor 1 during oogenesis and spermatogenesis.

OBJECTIVE: To determine the onset of gametocyte-specific factor 1 (Gtsf1) expression in embryogenesis and its relation to Nobox; and to determine its localization during gonadal development and gametocyte maturation. DESIGN: Developmental animal study. SETTING: University reproductive biology laboratory. ANIMAL(S): Mice ranging in age from embryonic day 12.5 to 8 weeks. INTERVENTION(S): Polymerase chain reaction and quantitative polymerase chain reaction were performed to determine the onset of and relative messenger RNA expression. Western blot was performed to confirm protein expression and antibody specificity. In situ hybridization and immunohistochemistry were used determine localization of expression. MAIN OUTCOME MEASURE(S): Gtsf1 messenger RNA expression levels during embryogenesis through adulthood in wild-type mice and in newborn Nobox knockout mice; GTSF1 expression and localization in postnatal mice. RESULT(S): Gtsf1 functions downstream of Nobox and is highly expressed in embryonic male and female gonads, localizing to germ cells throughout development. GTSF1 expression is confined to the cytoplasm in all stages of postnatal oocyte maturation and to prespermatogonia during early postnatal testicular development. CONCLUSION(S): The expression pattern of Gtsf1 and its high conservation suggests that it may play an important role in germ cell development. Further characterization of Gtsf1 may elucidate mechanisms involved in premature ovarian failure.