Germ cell nuclear factor

Germ cell nuclear factor (GCNF) is an orphan nuclear receptor for which a l igand has yet to be identified. However, we do know that GCNF binds to a no vel response element as a homodimer and regulates expression of genes, such as the protamines, through this element. In the absence of a ligand, GCNF is a transcriptional repressor that interacts with co-repressors. During em bryonic development, GCNF is expressed between the gastrula and neurula sta ges. Loss of GCNF causes embryonic lethality, disrupts normal somitogenesis , as well as neural tube and axis formation, suggesting that GCNF is a crit ical factor for normal embryonic development. In adult vertebrates, GCNF ex pression is predominantly found in the germ cells of gonads. GCNF expressio n in germ cells suggests that understanding its function in adults will yie ld greater insight into the regulation of gametogenesis, leading to new con traceptive targets. (C) 2001 Elsevier Science Ltd. All rights reserved.