title: Spermatid nuclear and sperm periaxonemal anomalies in the mouse Ube2b null mutant.
abstract: Ube2b (yeast Ubc2b/Rad6 homolog) null mice were described previously. Ube2b encodes the murine ubiquitin conjugating enzyme mHR6B. Ube2b(-/-) mice were shown to present male infertility and their sperm head shape anomalies suggested that Ube2b may be involved in the replacement of nuclear proteins during spermatid chromatin condensation. Apoptosis of spermatocytes suggested additional targets of Ube2b during spermatogenesis. Consistently, we found Ube2b transcription in both meiotic and postmeiotic stages by in situ hybridization. Immuno-electron microscopy revealed that transition proteins 1 and 2, protamines 1 and 2, and actin appear normally distributed during morphogenesis of Ube2b(-/-) spermatid heads. Surprisingly, electron microscopy revealed a particular sperm flagellum phenotype characterized by an abnormal distribution of periaxonemal structures. Flagellar anomalies of Ube2b null mice were previously described in infertile men indicating a possible genetic pathway for flagellar periaxonemal assembly in human.
authors.affiliation: Histologie Fonctionnelle et Moléculaire, Université Paris 5 and INSERM U.407, France. denise.escalier@biomedicale.univ-paris5.fr
authors.forename: Denise
authors.initials: D
authors.lastname: Escalier
authors.forename: Xi-Yuan
authors.initials: XY
authors.lastname: Bai
authors.forename: Derek
authors.initials: D
authors.lastname: Silvius
authors.forename: Pin-Xian
authors.initials: PX
authors.lastname: Xu
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
mesh_terms: D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000473:pathology; D017931:DNA Primers; D005838:Genotype; D017403:In Situ Hybridization; D008297:Male; D008540:Meiosis / Q000235:genetics; D051379:Mice; D016253:Microscopy, Immunoelectron; D016133:Polymerase Chain Reaction / Q000379:methods; D013077:Sperm Head / Q000473:pathology; D013087:Spermatids / Q000473:pathology / Q000648:ultrastructure*; D013091:Spermatogenesis / Q000235:genetics*; D013094:Spermatozoa / Q000002:abnormalities / Q000473:pathology / Q000648:ultrastructure*; D044763:Ubiquitin-Conjugating Enzymes / Q000172:deficiency* / Q000235:genetics* / Q000502:physiology
chemical_list: D017931:DNA Primers; C465394:Ube2b protein, mouse; D044763:Ubiquitin-Conjugating Enzymes