Nishikura K, Goldflam S, Vuocolo G A
Mol Cell Biol. 1985 Jun;5(6):1434-41. doi: 10.1128/mcb.5.6.1434-1441.1985.
We investigated the expression of the cloned human c-myc gene in Xenopus laevis oocytes microinjected with different recombinants. We found that microinjected plasmid DNA carrying an intact human c-myc gene directs efficient and faithful transcription from its own two promoters in X. laevis oocytes. This active transcription was unaffected by the presence of previously identified enhancing elements such as simian virus 72-base pair repeats or mouse immunoglobulin heavy-chain gene enhancer sequences in the construct in cis. This suggests that all necessary DNA sequences for accurate and faithful transcription recognized by the transcription machinery of the frog oocyte are self-contained. In addition, we have found that human c-myc transcripts synthesized in oocytes are properly polyadenylated at either one of two sites and also that the transcripts are spliced correctly but with low efficiency.
我们研究了在显微注射了不同重组体的非洲爪蟾卵母细胞中克隆的人c-myc基因的表达情况。我们发现，携带完整人c-myc基因的显微注射质粒DNA在非洲爪蟾卵母细胞中能从其自身的两个启动子高效且准确地指导转录。这种活跃转录不受构建体中顺式存在的先前鉴定的增强元件（如猿猴病毒72碱基对重复序列或小鼠免疫球蛋白重链基因增强子序列）的影响。这表明蛙卵母细胞转录机制识别的用于准确和忠实转录的所有必要DNA序列都是自成一体的。此外，我们还发现卵母细胞中合成的人c-myc转录本在两个位点之一进行了适当的多聚腺苷酸化，并且转录本也能正确剪接，但效率较低。
