title: SUN4 is essential for nuclear remodeling during mammalian spermiogenesis.
abstract: One of the more dramatic examples of cellular reorganization occurs during spermiogenesis in which a roughly spherical spermatid is transformed into a mature sperm cell. A highlight of this process involves nuclear remodeling whereby the round spermatid nucleus is sculpted into an elongated and polar structure. This transformation in nuclear architecture features chromatin condensation, changes in the composition and organization of the nuclear lamina and redistribution and elimination of nuclear pore complexes. The manchette, a cytoplasmic microtubule-based structure is thought to play a crucial role in the remodeling process. Here we show that SUN4, a spermatid nuclear membrane protein has an essential function in coupling the manchette to the nuclear periphery. In the absence of SUN4, manchette microtubules appear highly disorganized and the nucleus itself fails to elongate. Consequently, mice deficient in SUN4 display globozoospermia with associated infertility.
authors.affiliation: Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore. Electronic address: Alessandra.Calvi@imb.a-star.edu.sg.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Calvi
authors.affiliation: Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
authors.forename: Arnette Shi Wei
authors.initials: AS
authors.lastname: Wong
authors.affiliation: IMB Microscopy Unit, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
authors.forename: Graham
authors.initials: G
authors.lastname: Wright
authors.affiliation: Laboratory of Developmental and Regenerative Biology, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
authors.forename: Esther Sook Miin
authors.initials: ES
authors.lastname: Wong
authors.affiliation: Laboratory of Developmental and Regenerative Biology, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
authors.forename: Tsui Han
authors.initials: TH
authors.lastname: Loo
authors.affiliation: Laboratory of Developmental and Regenerative Biology, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
authors.forename: Colin L
authors.initials: CL
authors.lastname: Stewart
authors.affiliation: Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore. Electronic address: Brian.Burke@imb.a-star.edu.sg.
authors.forename: Brian
authors.initials: B
authors.lastname: Burke
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D005455:Fluorescent Antibody Technique; D017353:Gene Deletion; D006367:HeLa Cells; D059765:Homologous Recombination / Q000235:genetics; D006801:Humans; D008297:Male; D008322:Mammals / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D009685:Nuclear Envelope / Q000378:metabolism / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D020033:Protein Isoforms / Q000378:metabolism; D013087:Spermatids / Q000378:metabolism; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D020033:Protein Isoforms; C464932:SUN1 protein, mouse; C000605820:SUN4 protein, mouse
keywords: LINC complex; Nuclear envelope; SUN protein; Spermiogenesis