title: DAZ family proteins exist throughout male germ cell development and transit from nucleus to cytoplasm at meiosis in humans and mice.
abstract: The human DAZ gene family is expressed in germ cells and consists of a cluster of nearly identical DAZ (deleted in azoospermia) genes on the Y chromosome and an autosomal homolog, DAZL (DAZ-like). Only the autosomal gene is found in mice. Y-chromosome deletions that encompass the DAZ genes are a common cause of spermatogenic failure in men, and autosomal homologs of DAZ are essential for testicular germ cell development in mice and Drosophila. Previous studies have reported that mouse DAZL protein is strictly cytoplasmic and that human DAZ protein is restricted to postmeiotic cells. By contrast, we report here that human DAZ and human and mouse DAZL proteins are present in both the nuclei and cytoplasm of fetal gonocytes and in spermatogonial nuclei. The proteins relocate to the cytoplasm during male meiosis. Further observations using human tissues indicate that, unlike DAZ, human DAZL protein persists in spermatids and even spermatozoa. These results, combined with findings in diverse species, suggest that DAZ family proteins function in multiple cellular compartments at multiple points in male germ cell development. They may act during meiosis and much earlier, when spermatogonial stem cell populations are established.
authors.affiliation: Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA. reijo@itsa.ucsf.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Reijo
authors.forename: D M
authors.initials: DM
authors.lastname: Dorfman
authors.forename: R
authors.initials: R
authors.lastname: Slee
authors.forename: A A
authors.initials: AA
authors.lastname: Renshaw
authors.forename: K R
authors.initials: KR
authors.lastname: Loughlin
authors.forename: H
authors.initials: H
authors.lastname: Cooke
authors.forename: D C
authors.initials: DC
authors.lastname: Page
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002455:Cell Division / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D000075364:Deleted in Azoospermia 1 Protein; D005260:Female; D005854:Germ Cells / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008297:Male; D008540:Meiosis / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D011247:Pregnancy; D011506:Proteins / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D013737:Testis / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism*
chemical_list: C095668:DAZ1 protein, human; C101358:DAZL protein, human; D000075364:Deleted in Azoospermia 1 Protein; D011506:Proteins; D016601:RNA-Binding Proteins