Poly(A) tails are important elements in mRNA translation and stability, although recent genome-wide studies have concluded that poly(A) tail length is generally not associated with translational efficiency in nonembryonic cells. To investigate whether poly(A) tail size might be coupled to gene expression in an intact organism, we used an adapted TAIL-seq protocol to measure poly(A) tails in Caenorhabditis elegans. Surprisingly, we found that well-expressed transcripts contain relatively short, well-defined tails. This attribute appears to be dependent on translational efficiency, as transcripts enriched for optimal codons and ribosome association had the shortest tail sizes, whereas noncoding RNAs retained long tails. Across eukaryotes, short tails were a feature of abundant and well-translated mRNAs. This seems to contradict the dogma that deadenylation induces translational inhibition and mRNA decay and suggests that well-expressed mRNAs accumulate with pruned tails that accommodate a minimal number of poly(A)-binding proteins, which may be ideal for protective and translational functions.

中文翻译：

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短poly（A）尾巴是高表达基因的保守特征

聚（A）尾巴是mRNA翻译和稳定性中的重要元素，尽管最近的全基因组研究得出结论，聚（A）尾巴的长度通常与非胚性细胞的翻译效率无关。为了研究poly（A）尾巴的大小是否可能与完整生物体中的基因表达相关，我们使用了适应性的TAIL-seq方案来测量秀丽隐杆线虫的poly（A）尾巴。令人惊讶地，我们发现表达良好的转录本包含相对较短，定义明确的尾巴。此属性似乎取决于翻译效率，因为针对最佳密码子和核糖体缔合而富集的转录本具有最短的尾巴大小，而非编码RNA保留了长尾巴。在整个真核生物中，短尾巴是丰富且翻译良好的mRNA的特征。这似乎与这样的教条相矛盾，即腺苷酸化会诱导翻译抑制和mRNA衰减，并表明表达良好的mRNA会积聚修剪的尾巴，这些尾巴可容纳最少数量的poly（A）结合蛋白，这对于保护和翻译功能可能是理想的。