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Thiol Protease Inhibitor, E‐64‐d, Prevents Spindle Formation during Mouse Oocyte Maturation 1
Author(s) -
Hashimoto Naohiro,
Iwashita Shintaro,
ShojiKasai Yoko,
Kishimoto Takeo,
Imahori Kazutomo
Publication year - 1990
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1990.00197.x
Subject(s) - germinal vesicle , meiosis , oocyte , premature chromosome condensation , polar body , prophase , microbiology and biotechnology , chemistry , multipolar spindles , incubation , metaphase , protease , biology , spindle apparatus , chromosome , biochemistry , embryo , cell division , cell , enzyme , gene
E‐64‐d, a membrane permeant derivative of E‐64, the thiol protease inhibitor, was found to prevent meiotic maturation of mouse oocytes in a dose dependent manner. When immature mouse oocytes were incubated with E‐64‐d for up to 14 hr, first polar body emission was blocked to 36% at 200 μg/ml and 6% at 400 μg/ml, but germinal vesicle breakdown occurred normally. Cytological analysis revealed that meiotic spindles were not formed, while chromosome condensation occurred. Thus, E‐64‐d prevents oocytes from progressing to the first meiotic metaphase. When exposed to E‐64‐d after 8 hr of incubation without E‐64‐d, one‐fourth of oocytes completed the first meiotic division but never progressed to the second metaphase. In three‐fourth of the oocytes inhibited to emit the first polar body, spindles disappeared after incubation with E‐64‐d. The results suggest that E‐64‐d promotes disassembly of meiotic spindles resulting in inhibition of meiotic maturation. We propose that thiol protease is involved in spindle formation in mouse meiotic maturation.