Stranded RNA sequencing of Sodalis glossinidus - a bacterial endosymbiont of the Tsetse fly.. Transcriptional persistence in a degrading bacterial genome

Prokaryotic genomes are generally highly efficient, with relatively small amounts of ‘redundant’ sequence persisting; S. glossinidius, by contrast, exhibits extensive genomic degradation, wherein ~40% of its genome have been annotated as “pseudogenes”. To better characterise the functional capabilities of this bacterium, we have combined genomics, stranded RNA-seq, and proteomics to study whether pseudogenes exhibit function beyond their ‘degraded’ status. To that end, we have shown that although 34% of transcribed ORFs are pseudogenes, they show mean transcription approximately one-quarter that of “intact” coding sequences. Transcription level and protein abundance are positively correlated, suggesting that despite active transcription from putative pseudogenised genes, these are not associated with active translation