The dynamics of maternal poly(A)-containing mRNA in fertilized sea urchin eggs
The dynamics of maternal poly(A)-containing mRNA in fertilized sea urchin eggs
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海胆受精卵母体含 Poly(A) mRNA 的动态变化
DOI：
10.1016/0092-8674(77)90084-8
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发表时间：
1977
期刊：
影响因子：
64.5
通讯作者：
F. Wilt
中科院分区：
文献类型：
--
作者：
F. Wilt
在未受精的海胆卵中存在胞质多聚腺苷酸化的RNA，具有隔离mRNA的特征。鸡蛋激活后，聚(A)的量增加一倍，但总RNA含量保持不变。RNA在Poly(U)-Sepharose上的层析表明，在受精后2小时内，带有Poly(A)链的RNA的数量略有增加(约20%-30%)。当来自2小时受精卵的Poly(A)+mRNA的cDNA转录物与来自卵子或受精卵的Poly(A)+RNA反应时，两种制剂的再结合动力学似乎是相同的，因此含有Poly(A)的RNA序列在卵子和受精卵中是相同的。对卵子和受精卵的Poly(A)束长度的测量表明，数字平均长度从大约45个碱基增加到60个碱基。用放射性RNA的腺苷/AMP比值测量两个细胞受精卵的Poly(A)束长度表明，受精卵的Poly(A)束仅由放射性RNA解释，表明Poly(A)的广泛周转。结果表明，这些细胞的聚(A)束既有延长的，也有缩短的，在这种情况下，前者占优势。多聚(A)的增加不涉及不同序列的多腺苷基化，而是由于多腺化序列的数量和它们所承载的多聚(A)束的长度的增加。
Cytoplasmic polyadenylated RNA with the characteristics of sequestered mRNA exists in the unfertilized sea urchin egg. Following egg activation, the amount of poly (A) doubles, but total RNA content stays constant. Chromatography of the RNA on poly (U)-Sepharose shows that the amount of RNA that bears a poly (A) tract increases slightly (approximately 20-30%) during the 2 hr after fertilization. When a cDNA transcript of the poly (A)+ mRNA from 2 hr zygotes is reacted against poly (A)+ RNA from either eggs or zygotes, the kinetics of reassociation of the two preparations seem identical; hence the RNA sequences bearing poly (A) are the same in eggs and zygotes. Measurement of the length of the poly (A) tract in eggs and zygotes shows an increase in number average length from about 45 bases to 60 bases. Measurement of tract length of poly (A) in two cell zygotes by adenosine/AMP ratios of radioactive RNA shows that the poly (A) tract of the zygote is solely accounted for by radioactive RNA, indicating extensive turnover of the poly (A). It in concluded that the poly (A) tract in these cells is subject to both lengthening and shortening, with the former predominating in this instance. The increase in poly (A) does not involve polyadenylation of different sequences, but is due to an increase in the number of polyadenylated sequences and the length of the poly (A) tracts that they bear.