title: Mouse germ cell-less as an essential component for nuclear integrity.
abstract: A mouse homologue of the Drosophila melanogaster germ cell-less (mgcl-1) gene is expressed ubiquitously, and its gene product is localized to the nuclear envelope based on its binding to LAP2 beta (lamina-associated polypeptide 2 beta). To elucidate the role of mgcl-1, we analyzed two mutant mouse lines that lacked mgcl-1 gene expression. Abnormal nuclear morphologies that were probably due to impaired nuclear envelope integrity were observed in the liver, exocrine pancreas, and testis. In particular, functional abnormalities were observed in testis in which the highest expression of mgcl-1 was detected. Fertility was significantly impaired in mgcl-1-null male mice, probably as a result of severe morphological abnormalities in the sperm. Electron microscopic observations showed insufficient chromatin condensation and abnormal acrosome structures in mgcl-1-null sperm. In addition, the expression patterns of transition proteins and protamines, both of which are essential for chromatin remodeling during spermatogenesis, were aberrant. Considering that the first abnormality during the process of spermatogenesis was abnormal nuclear envelope structure in spermatocytes, the mgcl-1 gene product appears to be essential for appropriate nuclear-lamina organization, which in turn is essential for normal sperm morphogenesis and chromatin remodeling.
authors.affiliation: Department of Molecular Cell Biology, Research Institute for Microbial Diseases, Osaka University, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Kimura
authors.forename: Chizuru
authors.initials: C
authors.lastname: Ito
authors.forename: Shoko
authors.initials: S
authors.lastname: Watanabe
authors.forename: Tohru
authors.initials: T
authors.lastname: Takahashi
authors.forename: Masahito
authors.initials: M
authors.lastname: Ikawa
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yomogida
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Fujita
authors.forename: Megumi
authors.initials: M
authors.lastname: Ikeuchi
authors.forename: Noriko
authors.initials: N
authors.lastname: Asada
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Matsumiya
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okuyama
authors.forename: Masaru
authors.initials: M
authors.lastname: Okabe
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Toshimori
authors.forename: Toru
authors.initials: T
authors.lastname: Nakano
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000502:physiology*; D002843:Chromatin / Q000378:metabolism / Q000648:ultrastructure*; D005347:Fibroblasts; D018507:Gene Expression Regulation, Developmental; D007248:Infertility, Male / Q000235:genetics; D008099:Liver / Q000473:pathology; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010179:Pancreas / Q000473:pathology; D011479:Protamines / Q000235:genetics / Q000378:metabolism; D013091:Spermatogenesis / Q000235:genetics; D013094:Spermatozoa / Q000473:pathology*; D013737:Testis / Q000473:pathology
chemical_list: D002843:Chromatin; C471550:Gcl protein, mouse; D009687:Nuclear Proteins; C513176:Prm1 protein, mouse; D011479:Protamines; C068621:protamine 2