Chromatin and cytoplasmic characteristics of equine oocytes recovered by transvaginal ultrasound-guided follicle aspiration are influenced by the developmental stage of their follicle of origin
| Autor: | Armin Tuchscherer, Andreas Vernunft, Helmut Torner, H. Alm, Katrin Hinrichs, Wilhelm Kanitz |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Cytoplasm
endocrine system medicine.medical_specialty Population Oocyte Retrieval Estrous Cycle Glucosephosphate Dehydrogenase Suction Biology Follicle Ovarian Follicle Food Animals Internal medicine Follicular phase medicine Animals Horses Sperm Injections Intracytoplasmic Ovarian follicle Small Animals education Progesterone Atretic Follicle education.field_of_study Estradiol Equine Oocyte Follicular fluid Chromatin Follicular Fluid Mitochondria medicine.anatomical_structure Endocrinology Microscopy Fluorescence Oocytes Female Animal Science and Zoology Folliculogenesis |
| Zdroj: | Theriogenology. 80:1-9 |
| ISSN: | 0093-691X |
| DOI: | 10.1016/j.theriogenology.2013.03.023 |
| Popis: | Dynamic follicular changes occur during the equine estrus cycle, but little is known about their impact on the properties of recovered oocytes. The aim of this study was to characterize the cytoplasmic and chromatin status of equine oocytes in relation to the time of recovery during the follicle wave. Transvaginal ultrasound-guided follicle aspiration was performed two times in relation to the follicle wave: estrus-subordinate, from the subordinate follicles of mares in estrus, 24 hours after human chorionic gonadotropin stimulation of a dominant preovulatory follicle, and new-wave, from the follicles of the subsequent induced follicular wave, at the time of dominant follicle divergence (largest follicle 23 mm diameter). A total of 1011 follicles were aspirated. The oocyte recovery rate in the new-wave group was significantly lower than that for the estrus-subordinate group (12% vs. 26%, respectively); this was associated with a significantly higher proportion of oocytes with compact cumuli (44% vs. 27%, respectively). Estradiol concentrations were markedly higher in follicular fluid from new-wave follicles (885.6 ± 123.2 ng/mL vs. 54.3 ± 18.9 ng/mL, for estrus-subordinate; P < 0.001), indicating greater viability. Aspiration group did not affect glucose-6-phosphate dehydrogenase activity in recovered oocytes. Fibrillar (more juvenile) chromatin was more prevalent in new-wave oocytes, whereas estrus-subordinate oocytes showed more condensed chromatin or resumption of meiosis (P < 0.05). Mitochondrial activity was higher in oocytes with expanded cumuli in the new-wave group, but not in the estrus-subordinate group. In conclusion, our results clearly showed that the time of aspiration in relation to the follicle wave is associated with significant differences in follicle status and oocyte characteristics: new-wave oocytes were from a more viable follicle population and had more juvenile chromatin and cytoplasmic characteristics, whereas estrus-subordinate oocytes were from a more atretic follicle population and exhibited signs of atresia-related acquisition of meiotic and cytoplasmic competence. These findings will help in effective scheduling of oocyte recovery for equine-assisted reproduction techniques. |
| Databáze: | OpenAIRE |
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