Non‐random X‐chromosome expression early in mouse development
Non‐random X‐chromosome expression early in mouse development
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小鼠发育早期的非随机 X 染色体表达
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
I. Linke
中科院分区：
文献类型：
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作者：
V. Papaioannou;J. West;T. Bücher;I. Linke
我们使用了一种敏感的电泳技术来估计x染色体连接酶磷酸甘油酸激酶（PGK-1）的两种同工酶的活性或比率，以研究早期小鼠受孕的三个主要细胞系衍生物中x染色体表达的随机性。母系衍生的Pgk-1等位基因在Pgk-1a/Pgk-1b杂合胚胎的原始内胚层和滋养外胚层衍生物中优先表达于交媾后6 1/2天，在1个信息丰富的5 1/2天杂合胚胎中优先表达。在X染色体失活后不久，母体衍生的X染色体（Xm）优先表达的证据支持这样一种可能性，即Xm的优先表达是一次非随机X染色体失活的结果，而不是二次选择现象。在第4 1/2天和第5 1/2天分析的大多数胚胎只产生一个PGK-1条带，与Xm上PGK-1等位基因产生的同工酶相对应，尽管这些胚胎中有50%应该是杂合的雌性胚胎。讨论了可能的解释。
We have used a sensitive electrophoretic technique for estimating the activity, or ratio, of two allozymes of the X-chromosome-linked enzyme phosphoglycerate kinase (PGK-1), in order to investigate the randomness of X-chromosome expression in the derivatives of the three primary cell lineages of the early mouse conceptus. The maternally derived Pgk-1 allele is preferentially expressed in the derivatives of the primitive endoderm and trophectoderm lineages at 6 1/2 days post coitum in Pgk-1a/Pgk-1b heterozygous conceptuses, and in the one informative 5 1/2-day heterozygous conceptus analysed. This evidence for preferential expression of the maternally derived X chromosome (Xm), so soon after the time of X-chromosome inactivation, favors the possibility that the preferential expression of Xm is a consequence of primary non-random X-chromosome inactivation, rather than a secondary selection phenomenon. The majority of embryos analysed at 4 1/2 and 5 1/2 days pc produced only a single PGK-1 band, corresponding to the allozyme produced by the Pgk-1 allele on Xm, although 50% of these embryos should have been heterozygous females. Possible explanations are discussed.