title: Fate of centrosomes following somatic cell nuclear transfer (SCNT) in bovine oocytes.
abstract: Cloning mammalians by somatic cell nuclear transfer (SCNT) remains inefficient. A majority of clones produced by SCNT fail to develop properly and of those which do survive, some exhibit early aging, premature death, tumors, and other pathologies associated with aneuploidy. Alterations of centrosomes are linked to aberrant cell cycle progression, aneuploidy, and tumorigenesis in many cell types. It remains to be determined how centrosomes are remodeled in cloned bovine embryos. We show that abnormalities in either distribution and/or number of centrosomes were evident in approximately 50% of reconstructed embryos following SCNT. Moreover, centrosome abnormalities and failed 'pronuclear' migration which manifested during the first cell cycle coincided with errors in spindle morphogenesis, chromosome alignment, and cytokinesis. By contrast, nuclear mitotic apparatus protein (NuMA) exhibited normal expression patterns at metaphase spindle poles and in 'pronucleus' during interphase. The defects in centrosome remodeling and 'pronuclear' migration could lead to chromosome instability and developmental failures associated with embryo production by SCNT. Addressing these fundamental problems may enhance production of normal clones.
authors.affiliation: State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing.
authors.forename: Yunping
authors.initials: Y
authors.lastname: Dai
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Haiping
authors.initials: H
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Lyu
authors.forename: David L
authors.initials: DL
authors.lastname: Keefe
authors.forename: David F
authors.initials: DF
authors.lastname: Albertini
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
mesh_terms: D000818:Animals; D002417:Cattle; D018385:Centrosome / Q000648:ultrastructure*; D002869:Chromosome Aberrations; D019976:Cloning, Organism; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro; D005347:Fibroblasts / Q000648:ultrastructure; D006107:Granulosa Cells / Q000648:ultrastructure; D006822:Hybrid Cells; D021621:Imaging, Three-Dimensional; D008856:Microscopy, Fluorescence; D009687:Nuclear Proteins / Q000378:metabolism; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000648:ultrastructure*; D010312:Parthenogenesis; D008941:Spindle Apparatus / Q000648:ultrastructure
chemical_list: D009687:Nuclear Proteins