Chambers A, Old R
Department of Biological Sciences, University of Warwick, Coventry, United Kingdom.
Dev Biol. 1988 Feb;125(2):237-45. doi: 10.1016/0012-1606(88)90207-2.
Xenopus laevis histone H4 and H1 genes were transcribed in vitro to generate artificial precursor mRNAs (pre-mRNAs). These pre-mRNAs were microinjected into oocytes, matured oocytes, and unfertilized eggs of Xenopus laevis and their 3' cleavage and polyadenylation were investigated. In the oocyte nucleus both H4 and H1 pre-mRNAs were 3' cleaved but were not detectably polyadenylated. In the oocyte cytoplasm there was neither 3' cleavage nor polyadenylation of these histone pre-mRNAs. When injected into either matured oocytes or unfertilized eggs, the pre-mRNAs underwent 3' cleavage but this was inefficient when compared to the oocyte nucleus. In addition approximately 50% of the remaining uncleaved pre-mRNA was subject to a polyadenylation activity which added A tails of approximately 70 A residues. In contrast, artificial mouse beta-globin pre-mRNAs were not detectably 3' cleaved or polyadenylated in either microinjected oocytes or unfertilized eggs.
非洲爪蟾的组蛋白H4和H1基因在体外转录以生成人工前体mRNA（前体mRNA）。将这些前体mRNA显微注射到非洲爪蟾的卵母细胞、成熟卵母细胞和未受精卵中，并研究它们的3'切割和聚腺苷酸化情况。在卵母细胞核中，H4和H1前体mRNA均发生了3'切割，但未检测到明显的聚腺苷酸化。在卵母细胞细胞质中，这些组蛋白前体mRNA既没有3'切割也没有聚腺苷酸化。当注射到成熟卵母细胞或未受精卵中时，前体mRNA会发生3'切割，但与卵母细胞核相比效率较低。此外，大约50%未切割的剩余前体mRNA具有聚腺苷酸化活性，可添加约70个A残基的A尾。相比之下，人工小鼠β-珠蛋白前体mRNA在显微注射的卵母细胞或未受精卵中均未检测到明显的3'切割或聚腺苷酸化。
