人卵母细胞体外成熟前后线粒体分布的变化

目的 研究人未成熟和成熟卵母细胞中线粒体的分布,进一步阐明卵母细胞成熟和线粒体分布的关系.方法 未成熟卵母细胞和成熟卵母细胞均用Mito Tracker Green FM染色,经多聚甲醛固定后在激光扫描共焦显微镜下观察线粒体的分布.结果 线粒体在细胞质中的分布方式可分为:周边分布、半周边分布和均匀分布.在64.10%(50/78)的GV期卵母细胞中,线粒体呈周边分布.45.16%(28/62)的MI期卵母细胞中,线粒体仍维持周边分布;呈均匀分布的卵母细胞的比例为38.71%(24/62).体外培养成熟以后,线粒体在75.47%(80/106)的卵母细胞中呈现均匀分布.与体外培养成熟的卵母细胞相比,体内成熟的卵母细胞中线粒体分布最明显的特点是胞质中央区域线粒体的浓集,荧光强度高于周边区域.结论 人卵母细胞成熟前后,线粒体出现明显的分布变化,由未成熟卵母细胞中以周边分布为主变为成熟卵母细胞中以均匀分布为主.

CHANGE OF THE MITOCHONDRIAL DISTRIBUTION IN HUMAN OOCYTES BEFORE AND AFTER IN VITRO MATURATION

Objective To clarify the relationship between oocyte maturation and mitochondria distribution by investigating the distribution of mitochondrial in immatured and matured human oocytes. Methods Both immatured and matured oocytes were stained by Mito Tracker Green FM.After they were fixed by paraformaldehyde,the distribution of mitochondria was observed using laser scanning confocal microscope. Results Three mitochondria distribution patterns were identified: peripheral,semi-peripheral and evenly diffused.64.10%(50/78) of the GV oocytes presented a peripheral distribution of mitochondria.45.16%(28/62) of the MI oocytes had maintained the peripheral distribution,while 38.71%(24/62) presented a diffused status.After in vitro maturation,75.47%(80/106)of the oocytes displayed an evenly diffused type of distribution.Compared with the oocytes matured in vitro,the most marked feature of oocytes matured in vivo was that mitochondria distributed in the central region.Staining in the center of the oocyte was stronger than that in the peripheral region.Conclusion There were obvious changes in the distribution of mitochondria in human oocytes before and after maturation.The chief distribution pattern of mitochondria was changing from peripheral distribution in immatured oocytes to even diffusion in matured oocytes.