Hille M B, Hall D C, Yablonka-Reuveni Z, Danilchik M V, Moon R T
Dev Biol. 1981 Aug;86(1):241-9. doi: 10.1016/0012-1606(81)90336-5.
To determine whether initiation is rate-limiting in protein synthesis during the embryogenesis of sea urchins, polyribosome profiles of unfertilized eggs and cleavage, blastula and prism stage embryos were examined after incubation of the eggs and embryos in the presence and absence of low amounts of emetine, an inhibitor of polypeptide elongation. The ribosomes were radioactively labeled with [H]uridine by injection of the adults during oogenesis so that we could monitor emetine-dependent shifts of monoribosomes to polyribosomes. Although initiation is not rate limiting in unfertilized eggs or 2- to 16-cell embryos of Strongylocentrotus purpuratus, it is rate limiting in blastula and prism embryos. We suggest that initiation becomes rate limiting to allow the selective translation of certain classes of mRNA during later development.
为了确定在海胆胚胎发育过程中起始步骤是否是蛋白质合成的限速环节，在存在和不存在低剂量放线菌酮（一种多肽延伸抑制剂）的情况下孵育卵和胚胎后，检测了未受精卵以及卵裂期、囊胚期和棱柱期胚胎的多核糖体图谱。在卵子发生过程中通过注射[H]尿苷对成体进行放射性标记，以便我们能够监测放线菌酮依赖的单核糖体向多核糖体的转变。虽然在未受精卵或紫海胆的2至16细胞胚胎中起始步骤不是限速环节，但在囊胚和棱柱期胚胎中它是限速环节。我们认为起始步骤成为限速环节是为了在后期发育过程中允许对某些类别的mRNA进行选择性翻译。
