Emanuelsson Hadar
Zoophysiological Institute, University of Lund, Sweden.
Wilhelm Roux Arch Entwickl Mech Org. 1973 Mar;173(1):27-45. doi: 10.1007/BF00581668.
Karyomeres or chromosome vesicles occur regularly at all cell divisions in cleavage embryos ofOphryotrocha labronica up to the 16-cell stage. They are formed as separate units, containing one or several nucleolus-like bodies (NLB) as well as intranuclear annulate lamellae (IAL), but coalesce later into a compound nucleus, in connection with copious blebbing and simultaneous appearance of cytoplasmic annulate lamellae (CAL). Labelling of the early embryos withH-thymidine revealed marked localization of the synthesized DNA to the karyomere envelope region, whereasH-uridine incorporation, indicating RNA synthesis, was sparse and notably absent in the NLB. On the other hand the latter structure like the envelopes preferentially incorporatedH-myoinositol, and displayed considerable labelling withH-leucine. The mechanism and general significance of karyomere formation is discussed with particular attention to the NLB and their possible involvement in nuclear membrane formation.
在多毛纲动物Labronica的卵裂胚胎中，直到16细胞期，核粒或染色体小泡在所有细胞分裂中都会有规律地出现。它们作为独立的单位形成，包含一个或几个核仁样体（NLB）以及核内环形片层（IAL），但随后会合并成一个复合核，同时伴随着大量的泡状形成和细胞质环形片层（CAL）的同时出现。用³H-胸腺嘧啶核苷标记早期胚胎显示，合成的DNA明显定位于核粒包膜区域，而³H-尿苷掺入表明RNA合成较少，并且在核仁样体中明显不存在。另一方面，后者结构如包膜优先掺入³H-肌醇，并显示出³H-亮氨酸的大量标记。本文讨论了核粒形成的机制和一般意义，特别关注核仁样体及其可能参与核膜形成的情况。
