Transcription of three actin genes and a repeated sequence in isolated nuclei of sea urchin embryos.
Transcription of three actin genes and a repeated sequence in isolated nuclei of sea urchin embryos.
复制标题
海胆胚胎分离核中三个肌动蛋白基因和重复序列的转录。
DOI：
10.1016/0012-1606(87)90473-8
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发表时间：
1987
影响因子：
2.7
通讯作者：
CrainJr,WR
中科院分区：
文献类型：
--
作者：
Hickey,RJ;Boshar,MF;CrainJr,WR
在胚胎发育过程中的几个阶段，在分离的细胞核中测量了海胆Strongylocentrotus purpuratus的三个不连锁的肌动蛋白基因的相对转录。两个细胞骨架肌动蛋白基因 CyI 和 CyIIIa 的转录首次在 64-128 细胞胚胎中检测到。在早期阶段，每个胚胎的 CyIIIa 基因的活性是 CyI 的几倍。这两个基因的相对转录随着发育的进行而发生变化，因此到了黄体阶段，每个胚胎的 CyI 基因的活性至少是 CyIIIa 基因的两倍。这两个基因转录的初始检测时间以及它们在发育过程中相对转录的变化都与这些基因的 mRNA 在胚胎中的出现和相对丰度密切相关。肌肉肌动蛋白基因 M 的转录首先在黄体期胚胎的细胞核中检测到，因此也与肌肉肌动蛋白基因 mRNA 在胚胎中的首次出现密切相关。这些基因的 mRNA 在胚胎中的出现与它们在细胞核中转录的检测之间的紧密时间耦合表明它们的表达调节在很大程度上是转录性的。除了检查这些肌动蛋白基因的转录之外，我们还发现活跃转录的重复序列家族的成员位于肌肉肌动蛋白编码序列的上游。该序列在基因组中存在至少数百次，并且与在分裂阶段由RNA聚合酶III合成的RNA以及与在黄体阶段胚胎的细胞核中合成的RNA强烈杂交，在囊胚和原肠胚阶段几乎没有显示出杂交。
The relative transcription of three unlinked actin genes of the sea urchinStrongylocentrotus purpuratuswas measured in isolated nuclei, at several stages during embryonic development. Transcription of two cytoskeletal actin genes, CyI and CyIIIa, was first detected in 64–128 cell embryos. At the early stages, the CyIIIa gene is several-fold more active per embryo than CyI. The relative transcription of these two genes changes as development proceeds so that by the pluteus stage the CyI gene is at least twice as active per embryo as the CyIIIa gene. Both the time of initial detection of transcription of these two genes and the shift in their relative transcription during development correspond closely with the appearance and relative abundance in embryos of the mRNAs from these genes. Transcription of the muscle actin gene M was first detected in nuclei from pluteus stage embryos and thus also closely correlates with the first appearance of the muscle actin gene mRNA in embryos. The tight temporal coupling of the appearance in embryos of mRNA from these genes and the detection of their transcription in nuclei suggests that the regulation of their expression is in large part transcriptional. In addition to examining the transcription of these actin genes, we discovered that a member of an actively transcribed repeated sequence family is located upstream of the muscle actin-coding sequence. This sequence, which is present at least several hundred times within the genome and hybridizes strongly to RNA synthesized by RNA polymerase III at cleavage stages and to RNA synthesized in nuclei from pluteus stage embryos, shows little hybridization at blastula and gastrula stages.