Arceci R J, Senger D R, Gross P R
Cell. 1976 Sep;9(1):171-8. doi: 10.1016/0092-8674(76)90062-3.
The pattern of histone synthesis changes during development in sea urchins. One change involves two different lysine-rich histones. In Lytechinus, the late appearing histone, H1g, begins to be synthesized at gastrulation. Preformed ("maternal") mRNA of unfertilized eggs contains sequences that direct the synthesis of a part of the histone made during the period of cleavage. During that interval a different lysine-rich hsitone, H1m, is produced. Maternal mRNA is not, however, the sole source of templates for histone synthesis. Transcription of embryonic genomes provides the major translate both maternal and embryonic messages. A cell-free system derived from wheat germ was used to test RNAs from unfertilized eggs and from post-gastrula embryos for their capacity to direct the synthesis of histones, including the H1 types in vitro. Maternal mRNA includes templates for the synthesis of H1m, but it appears to lack those for H1g, since the cell-free system yields only H1m when challenged wigh egg RNA. Since the cell-free system is capable of translating H1g mRNA when presented with it, the synthesis of H1g is probably a very early developmental event controlled at the level of transcription.
海胆发育过程中组蛋白合成模式会发生变化。其中一个变化涉及两种不同的富含赖氨酸的组蛋白。在裂星海胆中，后期出现的组蛋白H1g在原肠胚形成时开始合成。未受精卵中预先形成的（“母体”）mRNA包含指导卵裂期部分组蛋白合成的序列。在此期间会产生另一种富含赖氨酸的组蛋白H1m。然而，母体mRNA并非组蛋白合成模板的唯一来源。胚胎基因组的转录为组蛋白合成提供了主要模板，既能翻译母体信息，也能翻译胚胎信息。使用从小麦胚芽中提取的无细胞系统来测试未受精卵和原肠胚后期胚胎的RNA指导体外合成组蛋白（包括H1类型）的能力。母体mRNA包含合成H1m的模板，但似乎缺乏合成H1g的模板，因为当用卵RNA进行测试时，无细胞系统仅产生H1m。由于当提供H1g mRNA时，无细胞系统能够翻译它，所以H1g的合成可能是在转录水平控制的非常早期的发育事件。
