In bacteria small regulatory RNAs (sRNAs) interact with their mRNA targets through non-consecutive base-pairing. The loose base-pairing specificity allows sRNAs to regulate large numbers of genes, either affecting the stability and/or the translation of mRNAs. Mechanisms enabling post-transcriptional regulation of the sRNAs themselves have also been described involving so-called sponge RNAs. Sponge RNAs modulate free sRNA levels in the cell through RNA-RNA interactions that sequester (“soak up”) the sRNA and/or promote degradation of the target sRNA or the sponge RNA-sRNA complex. The development of complex RNA sequencing strategies for the detection of RNA-RNA interactions has enabled identification of several sponge RNAs, as well as previously known regulatory RNAs able to act as both regulators and sponges. This review highlights techniques that have enabled the identification of these sponge RNAs, the origins of sponge RNAs and the mechanisms by which they function in the post-transcriptional network.

在细菌中，小的调节性RNA（sRNA）通过非连续碱基配对与其mRNA靶标相互作用。宽松的碱基配对特异性使sRNA可以调节大量基因，从而影响mRNA的稳定性和/或翻译。已经描述了涉及sRNAs自身的转录后调控的机制，涉及所谓的海绵RNAs。海绵RNA通过隔离（吸收）sRNA和/或促进目标sRNA或海绵RNA-sRNA复合物降解的RNA-RNA相互作用来调节细胞中的游离sRNA水平。用于检测RNA-RNA相互作用的复杂RNA测序策略的发展使得能够鉴定几种海绵RNA，以及能够同时充当调节剂和海绵的已知的调节RNA。