Pöting A, Danker K, Hartmann L, Köster M, Wedlich D, Knöchel W
Institut für Molekularbiologie und Biochemie, Freie Universität, Berlin.
Differentiation. 1990 Aug;44(2):103-10. doi: 10.1111/j.1432-0436.1990.tb00543.x.
Two related but clearly different cDNA clones corresponding to elongation factor 1 alpha (EF-1 alpha) mRNAs were isolated from a Xenopus laevis gastrula-stage library. Whereas the nucleotide sequences of these two cDNAs differ within the coding region at 49 out of 1386 positions (3.5%), the derived amino acid sequences are completely identical, thereby indicating a substantial evolutionary constraint on this translation factor. Southern-blot analysis of genomic DNA suggests that, besides the two closely related EF-1 alpha genes investigated in this study, other more-distantly related genes may exist in the X. laevis genome. Transcription of EF-1 alpha genes during oogenesis and embryonic development was studied by Northern-blot analysis and by in situ hybridizations. A high amount of EF-1 alpha mRNA was detected in previtellogenic oocytes. At later stages of embryonic development, EF-1 alpha mRNA was found to be accumulated in translationally active tissues.
从非洲爪蟾原肠胚期文库中分离出两个与延伸因子1α(EF-1α)mRNA相关但明显不同的cDNA克隆。这两个cDNA的核苷酸序列在编码区内1386个位置中的49个位置(3.5%)存在差异,但推导的氨基酸序列完全相同,从而表明对这种翻译因子存在显著的进化限制。基因组DNA的Southern印迹分析表明,除了本研究中研究的两个密切相关的EF-1α基因外,非洲爪蟾基因组中可能还存在其他关系较远的基因。通过Northern印迹分析和原位杂交研究了EF-1α基因在卵子发生和胚胎发育过程中的转录情况。在卵黄发生前的卵母细胞中检测到大量的EF-1α mRNA。在胚胎发育的后期阶段,发现EF-1α mRNA积累在翻译活跃的组织中。