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PRINT: ISSN 2221-1896
ONLINE : ISSN 2223-0343
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The effect of co-culturing denuded oocytes on the
in vitro maturation of bovine
cumulus-oocyte complexes |
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Sima Hemmatian Khayyat1, Abbas Parham1,2*
and Hesam Dehghani1,2
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1Division
of Physiology, Department of Basic Sciences, Faculty of Veterinary
Medicine, Ferdowsi University of Mashhad, Mashhad, Iran; 2Embryonic
and Stem Cell Biology and Biotechnology Research Group, Institute of
Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran
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Abstract |
The paracrine effects of oocyte secretions on the developmental
competence of oocyte are still under investigation. Oocyte-secreted
factors (OSFs) seem to
be involved in the maturation of bovine oocytes. Therefore,
this study was conducted to investigate
the effects of different concentrations of endogenous OSFs on the
in vitro maturation of bovine
cumulus-oocyte complexes (COCs).
For this purpose, COCs (n=1211) were aspirated from antral follicles of
ovaries collected from a local abattoir. Only oocytes surrounded by
complete and compact layers of cumulus cells with homogenous ooplasm
were defined as well-qualified COCs (n=353), whereas, other COCs (n=858)
with low quality were treated to obtain denuded oocytes (DOs).
The selected COCs were randomly
cultured in four groups: I) COCs cultured alone as control; II) COCs
co-cultured with DOs as 1:1 ratio; III) COCs co-cultured with DOs as 1:3
ratio, and IV) COCs co-cultured with DOs as 1:6 ratio. After maturation,
the two variables of cumulus expansion and nuclear status were assessed.
The complete cumulus expansion rate was 80% for the control group, and
75.27%, 72.63% and 76.25% for groups of II, III, and IV, respectively.
The percentage of metaphase II (MII) stage oocytes was 65.71% for the
control group, and 62.67%, 64.86% and 67.60%, for groups II, III, and
IV, respectively. Data analysis revealed that the rate of complete
expansion of cumulus cells and the development of MII stage oocytes in
experimental groups did not differ significantly as compared to the
control group. In conclusion, the different concentration of native OSFs
does not affect the rate of nuclear maturation and cumulus expansion of
bovine COCs. However, group size of co-cultured COCs can be of important
criterion for co-culturing systems.
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Keywords:
Oocyte-secreted factors; bovine,
In vitro maturation; cumulus expansion; Nuclear maturation |
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To cite this article:
Hemmatian Khayyat S, Parham A and Dehghani H,
2013.
The effect of co-culturing denuded oocytes on the
in vitro maturation of bovine
cumulus-oocyte complexes.
Res.
Opin. Anim. Vet. Sci., 3(12), 447-452. |
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