Histological and biological assessment of vitrified ovarian follicles from large animals
- PDF / 789,903 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 68 Downloads / 167 Views
REVIEW ARTICLE
Histological and biological assessment of vitrified ovarian follicles from large animals Rong-Mei Bao • Hiroaki Taketsuru Takashi Miyano
•
Received: 29 April 2011 / Accepted: 2 June 2011 / Published online: 19 June 2011 Ó Japan Society for Reproductive Medicine 2011
Abstract Mammalian ovaries contain mixed populations of follicles at different developmental stages. A combination of vitrification and growth culture of ovarian follicles could provide the desired number of mature eggs from a preserved small amount of ovarian tissues. Secondary and primordial follicles from porcine and bovine ovaries were vitrified in solutions containing ethylene glycol, dimethyl sulfoxide and different concentrations of sucrose, and assessed via histological examination, viability staining, xenografting to immunodeficient mice, and in vitro culturing. Histological examination revealed the damage to oocytes and the damage to follicle components separately. The effects of sucrose in vitrification solutions on the follicles were different depending on the developmental stage of the follicle, oocyte size, cell type in the follicle, and species. Viability staining with fluorescein diacetate was useful to assess the damage to oocytes in secondary follicles. In the xenografts, vitrified bovine primordial and secondary follicles developed to the antral stage, and vitrified porcine primordial follicles developed to the secondary stage. Furthermore, bovine secondary follicles formed antrum-like structures in culture. These results suggest that histological examination and viability staining are valuable for assessing the direct effects of vitrification and warming conditions on follicles and oocytes, while xenografting and in vitro culturing can be useful for evaluating the developmental ability of vitrified follicles and oocytes.
R.-M. Bao H. Taketsuru T. Miyano (&) Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe 657-8501, Japan e-mail: [email protected]
Keywords Bovine Ovarian follicle Porcine SCID mouse Vitrification
Introduction Mammalian ovaries contain mixed populations of follicles at different developmental stages. Primordial follicles are most abundant in the ovary, and each of the follicles consists of a non-growing oocyte arrested at the prophase of meiosis I and a single layer of flat-shaped granulosa cells that surround the oocyte. As the oocyte starts to grow, the granulosa cells change their morphology to a cuboidal shape to form a primary follicle. Granulosa cells further proliferate and become multilayered, and theca cells surround the follicle, causing the formation of a secondary follicle. Thereafter, a large fluid-filled cavity is formed, and the follicle becomes an antral follicle. During follicular development, enclosed oocytes 30 lm in diameter in porcine and bovine ovaries grow to a final size 120–125 lm in diameter and acquire the competence to resume meiosis I, mature to metaphase II, and be fertilized. Artificial growing-up of non-growing and growing oocytes i
Data Loading...
