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Asymmetric division of spindle microtubules and microfilaments during bovine meiosis from metaphase I to metaphase III
Author(s) -
Li GuangPeng,
Liu Ying,
Bunch Thomas D.,
White Kenneth L.,
Aston Kenneth I.
Publication year - 2005
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.20255
Subject(s) - anaphase , telophase , metaphase , biology , polar body , meiosis , meiosis ii , spindle apparatus , microbiology and biotechnology , spindle pole body , spermatocyte , multipolar spindles , oocyte , genetics , chromosome , cell division , embryo , cell , gene
Abstract The kinetics of spindle and chromosomes during bovine oocyte meiosis from meiosis I to meiosis III is described. The results of this study showed that (1) oocytes began to extrude the first polar body (Pb1) at the early anaphase I stage and the Pb1 totally separated from the mother cell only when oocytes reach the MII stage; (2) the morphology of the spindle changed from barrel‐shaped at the metaphase stage to cylinder‐shaped at early anaphase, and then to a thin, long triangle‐shaped cone at late anaphase and telophase stages; (3) chromosome morphology went from an individual visible stage at metaphase to a less defined chromatin state during anaphase and telophase stages, and then back to visible individual chromosomes at the next metaphase; (4) chromatin that connected with the floor of the cone became the polar bodies and expelled, and almost all of the microtubules (MTs) and microfilaments (MFs) composing the spindles moved towards and contributed to the polar bodies; and (5) the size of the metaphase I (MI) spindle was larger than the metaphase II (MII) and metaphase III (MIII) spindles. The MII spindle, however, is more barrel‐shaped than the MI spindle. This study suggests that spindle MTs and MFs during bovine oocyte meiosis are asymmetrically divided into the polar bodies. Mol. Reprod. Dev. 71: 220–226, 2005. © 2005 Wiley‐Liss, Inc.