Lu Yong-qing, He Xie-chao, Zheng Ping
State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China Yunnan Key Laboratory of Animal Reproduction, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China Yunnan Key Laboratory of Animal Reproduction, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
Mol Hum Reprod. 2016 Apr;22(4):252-60. doi: 10.1093/molehr/gaw001. Epub 2016 Jan 14.
What factors in mouse oocytes are involved in the ageing-related decline in oocyte quality?
The maternal effect gene Mater is involved in ageing-related oocyte quality decline in mice.
Premature loss of centromere cohesion is a hallmark of ageing-related oocyte quality decline; the maternal effect gene Mater (maternal antigen that embryos require, also known as Nlrp5) is required for preimplantation embryo development beyond the 2-cell stage, and mRNA expression of Mater decreases with maternal ageing.
STUDY DESIGN, SAMPLES/MATERIALS, METHODS: Mater protein expression level in mature oocytes from 7 young (5-8 weeks old) to 7 old mice (41-68 weeks old) was compared by immunoblotting analysis. Wild-type and Mater-null mice were used to examine whether Mater is necessary for maintaining normal centromere cohesion by means of cytogenetic karyotyping, time-lapse confocal microscopy and immunofluorescence staining.
Mater protein is decreased in mature oocytes from old versus young mice (P = 0.0022). Depletion of Mater from oocytes leads to a reduction in centromere cohesion, manifested by precocious sister chromatid separation, enlargement of sister centromere distance and misalignment of chromosomes in the metaphase plate during meiosis I and II.
LIMITATIONS, REASONS FOR CAUTION: This study was conducted in mice. Whether or not the results are applicable to human remains further elucidation. In addition, we were unable to confirm if the strain of mice (C57BL/6XSv129) at the age of 41-68 weeks old has the 'cohesin-loss' phenotype.
Investigating Mater's functional mechanisms could provide fresh insights into understanding how the ageing-related oocyte quality decline occurs.
N/A.
This work was supported by the research grant from Chinese NSFC to P.Z. (31071274). We have no conflict of interests to declare.
小鼠卵母细胞中哪些因素与衰老相关的卵母细胞质量下降有关？
母体效应基因Mater与小鼠衰老相关的卵母细胞质量下降有关。
着丝粒凝聚力过早丧失是衰老相关卵母细胞质量下降的一个标志；母体效应基因Mater（胚胎所需的母体抗原，也称为Nlrp5）是2细胞期之后的植入前胚胎发育所必需的，并且Mater的mRNA表达随着母体衰老而降低。
研究设计、样本/材料、方法：通过免疫印迹分析比较了7只年轻（5 - 8周龄）和7只老年小鼠（41 - 68周龄）成熟卵母细胞中Mater蛋白的表达水平。使用野生型和Mater基因敲除小鼠，通过细胞遗传学核型分析、延时共聚焦显微镜和免疫荧光染色来检查Mater对于维持正常着丝粒凝聚力是否必要。
与年轻小鼠相比，老年小鼠成熟卵母细胞中的Mater蛋白减少（P = 0.0022）。卵母细胞中Mater的缺失导致着丝粒凝聚力降低，表现为减数分裂I和II期间姐妹染色单体过早分离、姐妹着丝粒距离增大以及中期板中染色体排列紊乱。
局限性、需谨慎的原因：本研究是在小鼠中进行的。这些结果是否适用于人类仍有待进一步阐明。此外，我们无法确定41 - 68周龄的小鼠品系（C57BL/6XSv129）是否具有“黏连蛋白丧失”表型。
研究Mater的功能机制可为理解衰老相关的卵母细胞质量下降如何发生提供新的见解。
无。
本研究得到了中国国家自然科学基金资助给P.Z.的研究经费（31071274）。我们没有利益冲突需要声明。
