Talk among yourselves: RNA sponges mediate cross talk between functionally related messenger RNAs

When Francis Crick first proposed the central dogma, he predicted that genetic information flows from DNA to RNA and finally to proteins. By this classical concept, the sole purpose of mRNA is to serve as a template for translation. Recent work has expanded our understanding of the function of mRNA well beyond this singular definition. A paper published in this issue sheds more light on the myriad roles mRNAs can play in genetic regulation. Miyakoshi et al () report an intriguing scenario in Salmonella where a small RNA molecule derived from a larger polycistronic mRNA promotes cross talk between physically unlinked mRNAs via controlling turnover of a global small RNA repressor. Recent work shows that bacterial RNAs can act as sponges for sRNAs, thereby altering the regulatory outcome for downstream target mRNAs.