title: Crucial role of Bysl in mammalian preimplantation development as an integral factor for 40S ribosome biogenesis.
abstract: Blastocyst formation during mammalian preimplantation development is a unique developmental process that involves lineage segregation between the inner cell mass and the trophectoderm. To elucidate the molecular mechanisms underlying blastocyst formation, we have functionally screened a subset of preimplantation embryo-associated transcripts by using small interfering RNA (siRNA) and identified Bysl (bystin-like) as an essential gene for this process. The development of embryos injected with Bysl siRNA was arrested just prior to blastocyst formation, resulting in a defect in trophectoderm differentiation. Silencing of Bysl by using an episomal short hairpin RNA expression vector inhibited proliferation of embryonic stem cells. Exogenously expressed Bysl tagged with a fluorescent protein was concentrated in the nucleolus with a diffuse nucleoplasmic distribution. Furthermore, the loss of Bysl function by using RNA interference or dominant negative mutants caused defects in 40S ribosomal subunit biogenesis. These findings provide evidence for a crucial role of Bysl as an integral factor for ribosome biogenesis and suggest a critical dependence of blastocyst formation on active translation machinery.
authors.affiliation: Institute of Medical Science, University of Tokyo, Minato-ku, Toyko 108-8639, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Adachi
authors.forename: Chie
authors.initials: C
authors.lastname: Soeta-Saneyoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sagara
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Iwakura
mesh_terms: D000818:Animals; D001483:Base Sequence; D001755:Blastocyst; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004622:Embryo, Mammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D012269:Ribosomal Proteins / Q000096:biosynthesis*
chemical_list: C504465:Bysl protein, mouse; D015815:Cell Adhesion Molecules; D034741:RNA, Small Interfering; D012269:Ribosomal Proteins