Antral follicular count and its relationship with ovarian volume, preantral follicle population and survival, oocyte meiotic progression and ultrastructure of in vitro matured bovine cumulus–oocyte complexes
Summary This study aimed to evaluate the relationship between antral follicular count (AFC) and ovarian volume (OV), preantral follicular population and survival, meiotic progression and ultrastructure of cumulus–oocyte complexes (COCs) after in vitro maturation. In experiment 1, the relationship be...
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Published in | Zygote (Cambridge) Vol. 28; no. 6; pp. 495 - 503 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Cambridge University Press
01.12.2020
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Subjects | |
Online Access | Get full text |
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Summary: | Summary
This study aimed to evaluate the relationship between antral follicular count (AFC) and ovarian volume (OV), preantral follicular population and survival, meiotic progression and ultrastructure of cumulus–oocyte complexes (COCs) after
in vitro
maturation. In experiment 1, the relationship between AFC and preantral follicle population and survival was evaluated by classical histology. In experiment 2, the relationship among AFC, OV, ability of oocytes to resume meiosis and ultrastructure of
in vitro
matured bovine COCs was studied. A positive correlation (
P
< 0.05) between AFC and the numbers of healthy primordial, degenerate and total follicles was observed, as well as with healthy secondary follicles and total follicles. The numbers of grades I and II oocytes in ovaries of high AFC class were higher compared with those with intermediate or lower AFC. After
in vitro
maturation, COCs from ovaries of high AFC had a higher percentage of oocytes in metaphase II compared with those of intermediate and low AFC (
P
< 0.0001). Ovaries of intermediate AFC had a higher percentage of oocytes in metaphase II compared with ovaries with low AFC (
P
< 0.0001). The proportion of oocytes in metaphase I, telophase I and anaphase I in COCs from ovaries of intermediate AFC (26.04%) was higher (
P
< 0.05) compared with that seen in COCs of ovaries with high (8.55%) and low (14.15%) AFC. No differences in the ultrastructure of oocytes were seen. In conclusion, after
in vitro
maturation, cow ovaries with high AFC have higher numbers of oocytes that reach in metaphase II (MII), but they also have higher numbers of degenerated primordial and primary follicles. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0967-1994 1469-8730 |
DOI: | 10.1017/S0967199420000386 |