Expression of caspase and BCL-2 apoptotic family members in mouse preimplantation embryos
Expression of caspase and BCL-2 apoptotic family members in mouse preimplantation embryos
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DOI：
10.1095/biolreprod61.1.231
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发表时间：
1999-07-01
影响因子：
3.6
通讯作者：
Warner, CM
中科院分区：
文献类型：
--
作者：
Exley, GE;Tang, CY;Warner, CM
由卵裂球和DNA片段化确定的细胞凋亡发生在许多植入前小鼠胚胎中。为了研究哪些基因与植入前胚胎的细胞凋亡有关，我们用逆转录聚合酶链式反应检测了caspase家族中的七个基因和bcl2家族中的七个基因的mRNA水平。所有caspase mRNAs在卵母细胞中均可检测到，而在植入前胚胎中的表达具有阶段特异性。对第二组caspase活性的测定表明，虽然在受精卵中没有检测到这些caspase的转录本，但在极体、碎裂的受精卵和经星状孢子素处理的受精卵中都可以检测到蛋白分解活性。这表明母体caspase在卵子发生过程中是遗传的。在植入前发育的每个阶段都可以检测到bcl2家族一些成员的转录本。很少检测到其他成员的文字记录。当使用免疫荧光法评估bcl2和bax蛋白水平时，在受精卵和囊胚中都检测到这两种蛋白。当将碎裂胚泡与正常胚泡进行比较时，碎裂胚泡的bcl2免疫荧光水平往往较低。这一结果支持了一个模型，在该模型中，bcl2/bax的比例在凋亡的胚胎中发生了变化。
Apoptosis, as determined by blastomere and DNA fragmentation, occurs in many preimplantation mouse embryos. To investigate which genes contribute to apoptosis in preimplantation embryos, we used the reverse transcription-polymerase chain reaction to assess mRNA levels for seven genes in the caspase family and seven genes in the BCL-2 family. All caspase mRNAs were detectable in oocytes, while expression in preimplantation embryos varied in a stage-specific manner. An assay for group II caspase enzymatic activity showed that although transcripts for these caspases could not be detected in zygotes, proteolytic activity could be detected in polar bodies, fragmented zygotes, and zygotes treated with staurosporine. This suggests that maternal caspases are inherited during oogenesis. Transcripts for some members of the BCL-2 family could be detected at every stage of preimplantation development. Transcripts for other members were rarely detected. When BCL-2 and BAX protein levels were assessed using immunofluorescence, both proteins were detected in zygotes and in blastocysts. When fragmented blastocysts were compared to normal blastocysts, levels of BCL-2 immunofluorescence tended to be lower in fragmented blastocysts. This result supports a model in which the ratio of BCL-2 to BAX is altered in apoptotic embryos.