Timing of <i>in vivo</i> maturation of equine preovulatory oocytes and competence for <i>in vitro</i> maturation of immature oocytes collected simultaneously

Equine Veterinary Journal - Tập 29 Số S25 - Trang 33-37 - 1997
J. Bézard1, A. Mekarska1, Philippe Monget1, Guy Duchamp1, E. Palmer1
1Unité Reproduction Equine, INRA-Haras Nationaux, 37380 Nouzilly, France.

Tóm tắt

SummaryThe objects of this study were to monitor the development of the cumulus complex and nuclear maturation in oocytes recovered from preovulatory follicles following treatment to induce ovulation and to investigate the in vitro maturation competence of oocytes recovered from smaller nonpreovulatory follicles of varying size. All follicles ≤5 mm in pony mares were individually punctured at 0, 6, 12, 24 and 35 h after an injection of LH to induce ovulation. The recovery rates of oocytes were 64% from 55 preovulatory follicles, 22% from 32 subordinate follicles and 52% from 227 small follicles. Cumulus expansion of the preovulatory oocytes occurred at 12 h post LH treatment while the metaphase I and II components of nuclear maturation were not completed until 24 and 35 h post LH respectively. For nonpreovulatory follicles, the frequency of atresia and oocyte competence for in vitro nuclear maturation both increased with increasing follicular size.

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Tài liệu tham khảo

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Equine Veterinary Journal

Tập 29 Số S25

33-37

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