Over twenty years ago Galtier and Lobry published a manuscript entitled “Relationships between Genomic G + C Content, RNA Secondary Structure, and Optimal Growth Temperature” in the Journal of Molecular Evolution that showcased the lack of a relationship between genomic G + C content and optimal growth temperature (OGT) in a set of about 200 prokaryotes. Galtier and Lobry also assessed the relationship between RNA secondary structures (rRNA stems, tRNAs) and OGT, and in this case a clear relationship emerged. Increasing structured RNA G + C content (particularly in regions that are double-stranded) correlates with increased OGT. Both of these fundamental relationships have withstood test of many additional sequences and spawned a variety of different applications that include prediction of OGT from rRNA sequence and computational ncRNA identification approaches. In this work, I present the motivation behind Galtier and Lobry’s original paper and the larger questions addressed by the work, how these questions have evolved over the last two decades, and the impact of Galtier and Lobry’s manuscript in fields beyond these questions.

二十多年前，Galtier 和 Lobry 在Journal of Molecular Evolution 上发表了一篇题为“Relationships between Genomic G + C Content, RNA Secondary Structure, and Optimal Growth Temperature”的手稿这表明在一组约 200 个原核生物中，基因组 G + C 含量与最佳生长温度 (OGT) 之间缺乏关系。Galtier 和 Lobry 还评估了 RNA 二级结构（rRNA 茎、tRNA）和 OGT 之间的关系，在这种情况下出现了明确的关系。增加结构化 RNA G + C 含量（特别是在双链区域）与增加的 OGT 相关。这两种基本关系都经受住了许多附加序列的测试，并催生了各种不同的应用，包括从 rRNA 序列预测 OGT 和计算 ncRNA 鉴定方法。在这项工作中，我展示了 Galtier 和 Lobry 原始论文背后的动机以及工作解决的更大问题，这些问题在过去二十年中是如何演变的，