Nontemplated nucleotide addition prior to polyadenylation:: A comparison of Arabidopsis cDNA and genomic sequences
Nontemplated nucleotide addition prior to polyadenylation:: A comparison of Arabidopsis cDNA and genomic sequences
复制标题
作者：
Jin, YF;Bian, TF
拟南芥DNA序列的比较显示，在大约一半的拟南芥mRNA的3'末端的最后一个核苷酸，紧邻poly（A）尾的上游，与相应的基因组序列不同。这表明在多聚腺苷酸化之前在这些mRNA的3'末端添加了额外的核苷酸。在含有额外核苷酸的mRNA中，约65%具有单个额外核苷酸，其中核苷酸C最常见。这种在加入poly（A）序列之前的非模板化的添加可能是经常观察到的转录产物异质性的主要促成因素。这些结果将有助于阐明mRNA 3 '端加工的机制。
A comparison of Arabidopsis DNA sequences revealed that the final nucleotides at the 3' end of approximately half of the Arabidopsis mRNAs, immediately upstream of the poly(A) tail, differ from the corresponding genomic sequences. This suggests that extra nucleotides were added to these mRNAs at their 3' termini prior to polyadenylation. Among the mRNAs containing additional nucleotides, approximately 65% had a single additional nucleotide, with the nucleotide C added most often. This nontemplated addition before the addition of the poly(A) sequence could be a major contributing factor to the often observed heterogeneity in transcription products. These findings should be helpful in the elucidation of the mechanisms of mRNA 3'-end processing.