Effect of preantral mouse follicle culture period on meiotic maturation and developmental competence of oocytes
ABSTRACT PurposeThe aim of this study is to determine the optimal culture period for meiotic maturation and developmental competence of invitro-grown
MethodsEarly preantral follicles with diameter of 100–130μm were collected mechanically from day14 mouse ovaries and cultured for
8, 10, and 12days. The diameters of follicles and oocytes were measured, and chromatin configuration in oocytes was observed.
We also examined meiotic maturation by human chorionic gonadotropin (hCG)/epidermal growth factor (EGF) stimulation, developmental
competence of fertilized oocytes to blastocysts, and apoptosis in blastocysts.
ResultsThe follicular diameter increased significantly from days4 to 10, and the diameter of day12 oocytes was significantly larger
than day8 or earlier oocytes. Chromatin configuration around the nucleolus was transformed from “nonsurrounded (immature)”
to “surrounded (mature)” after 10days. Furthermore, MII rate of day10 and 12 oocytes was significantly higher than that
of day8 oocytes. The blastocyst rate of day10 oocytes was higher than that of day8 or 12 oocytes. The blastocyst apoptotic
rate of day12 oocytes was higher than that of day10 oocytes.
ConclusionsLong culture periods of invitro-grown oocytes affect meiotic maturation, developmental competence to blastocysts, and apoptosis.
KeywordsApoptosis-Culture period-Invitro growth-Mouse-Preantral follicle
Full-textDOI: · Available from: Toshitaka Horiuchi, Mar 24, 2014
- [Show abstract] [Hide abstract]
ABSTRACT: Bovine ovaries offer a large pool of oocytes that could be used for in vitro production of embryos of genetically valuable animals. The effects of in vitro growth (IVG) culture duration (10, 12, and 14 days) on the viability and growth of bovine oocytes derived from early antral follicles (0.5-1 mm diameter) in this study. In addition, the effect of pre-IVM culture with phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine) on nuclear maturation of IVG oocytes was also evaluated. In experiment 1, oocyte viability observed after 10 or 12 days of IVG culture was greater (P < 0.05) than that observed after 14 days of culture. Oocyte diameters and proportions of oocytes at metaphase II stage were greater (P < 0.05) when 12 or 14 days of IVG culture where used when compared with 10 days culture. In addition, the proportion of oocytes at metaphase II stage was greater (P < 0.05) when pre-IVM culture was performed for oocytes derived from 12 and 14 days of IVG culture. When 12 and 14 days of IVG culture followed by pre-IVM culture were compared in experiment 2, cumulus cell membrane integrity was greater (P < 0.05) after 12 days. Blastocyst production rate for oocytes obtained after 12 days of IVG culture (24.5%) was greater (P < 0.05) than for oocytes obtained after 14 days (9.9%). In conclusion, 12 days IVG followed by pre-IVM culture was considered the optimal processing system for bovine oocytes derived from early antral follicles when oocyte viability, diameter, maturation, and development competences were considered.Theriogenology 08/2013; 80(7). DOI:10.1016/j.theriogenology.2013.07.004 · 1.85 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: To obtain insight into the effects of androstenedione on ovarian folliculogenesis and oogenesis. Experimental study. St. Marianna University School of Medicine. Prepubertal (14-day-old) BDF1 female mice. Early secondary follicles were isolated from the ovaries and were cultured individually in vitro with or without androstenedione (10(-11) to 10(-5) M) for 12 days. Thereafter, the follicles were treated with hCG and epidermal growth factor (EGF). Diameters and morphology of follicles and oocytes; E(2) and P secretion; and chromatin configuration and expression of growth differentiation factor 9 (GDF9) in oocytes were examined. Early secondary follicles developed to the preovulatory stage. Androstenedione treatments increased the follicle diameters, reduced survival rates of follicles, and promoted the formation of follicles with abnormal morphology, including misshapen oocyte. The secretion of E(2) and P was significantly higher in androstenedione-exposed follicles. Androstenedione prevented the alteration in chromatin configuration and reduced oocyte GDF9 expression. When follicles cultured with androstenedione were treated with hCG and EGF, the first polar body exclusion, chromosome alignment on metaphase plate, and spindle assembly were inhibited in the oocytes. These results demonstrate that excess androgen induces abnormalities in the morphology and function of developing oocytes, which impairs oocyte meiotic competence.Fertility and sterility 02/2012; 97(2):469-76. DOI:10.1016/j.fertnstert.2011.11.040 · 4.30 Impact Factor