- 學位論文
老化母鼠對卵子品質與胚胎發育的影響
Impact of aging female on the oocyte quality and embryo development in mice
摘要
近年來女性的生育能力隨著年齡的增長而下降。有研究顯示，卵巢中卵母細胞的消耗以及卵母細胞品質下降與年齡的增長有密切相關。然而，更年期前對生殖生理的衰老仍然未知。本研究的目的是研究女性年齡增長是否會影響體內和體外卵母細胞品質及胚胎發育。首先我們觀察6-9、24、28和32週齡母鼠是否影響懷孕率、胎兒的存活率/吸收率以及胎兒和胎盤的重量。結果顯示，24-32週齡母鼠之懷孕率、胎兒存活率和吸收率無明顯差異，可能所使用的實驗組別母鼠週齡還尚未達到所謂的老年化。因此再提高母鼠週齡為6-10、40、44，48及52週齡，於母鼠懷孕第四天取得囊胚時期之胚胎，以含有20% 血清的CMRL-1066培養液中進行體外八天培養，觀察囊胚的孵化、貼附和體外生長的型態，結果顯示母鼠懷孕第四天取得囊胚數量隨著母鼠週齡的增長有減少趨勢 (p < 0.05)。為了瞭解卵巢中所排出卵子是否降低胚胎存活率，因此將7-12，40-48、50-58及60-63週齡範圍的母鼠所取得的卵母細胞進行體外授精 (In vitro fertilization，IVF)，並將受精卵進行四天分裂期胚胎培養，結果顯示40-63週齡母鼠所取得平均卵母細胞和受精卵數量有顯著減少 (p < 0.01)；在50-63週齡母鼠中，發育至4-8，16-32細胞期和囊胚期胚胎的比例有顯著減少 (p < 0.01)。我們的研究結果顯示，40週齡以上的母鼠可能會影響卵子品質與胚胎發育。
並列摘要
In recent years, female fertility is decreased with advancing age. Considerable evidence has suggested that the gradual depletion of oocytes in ovary as well as the decrease of oocytes quality is highly associated with increasing age. However, the aging before the menopause on reproductive physiology is still unknown. The aim of this study is to investigate whether the female with increased age have an impact on the oocyte quality and the embryo development in vivo and in vitro. Mice from 6-9, 24, 28 or 32-week-old produced pregnancy rate, the survival fetus, resorption, the weight of fetus or placenta were examined. Results showed that the ratio of pregnancy, survival fetus and resorption were not significant different. Age of the experimental groups might not be enough to reach the aged reproductive physiology in mouse. Therefore, Blastocysts from day 4 of pregnant mice from 6-10, 40, 44, 48 or 52-week-old were cultured in CMRL-1066 containing 20% of cord blood serum for 8 days. Blastocysts developed as hatched, attachment or outgrowth onto dish was examined. Results showed that numbers of blastocysts obtained from day 4 of pregnant mice were significantly decreased with advancing age (p< 0.05). Further, to learn the oocytes derived from aging ovaries whether decrease their viability of embryo development. Oocytes were obtained from different ages (7-12 weeks, 40-48 weeks, 50-58 weeks, 60-63 weeks) female mice were submitted to in vitro fertilization (IVF) and zygotes were cultured for 4 day. Results showed that the average number of oocytes or zygotes from 40-48, 50-58, 60-63 weeks female were significantly decreased (p< 0.01). Percentage of embryos developed as 4-8, 16-32 cells stage or blastocysts were significantly decreased on 50-58, 60-63 weeks females (p< 0.01). Our results suggested that aging females over 40 weeks old may has an impact on the oocyte quality and embryo development in female mice.