Diversification of the < i > Caenorhabditis < /i > heat shock response by Helitron transposable elements

Heat Shock Factor 1 (HSF-1) is a key regulator of the heat shock response (HSR). Upon heat shock, HSF-1 binds well-conserved motifs, called Heat Shock Elements (HSEs), and drives expression of genes important for cellular protection during this stress. Remarkably, we found that substantial numbers of HSEs in multipleCaenorhabditis species reside within Helitrons, a type of DNA transposon. Consistent with Helitron-embedded HSEs being functional, upon heat shock they display increased HSF-1 and RNA polymerase II occupancy and up-regulation of nearby genes inC. elegans. Interestingly, we found that different genes appear to be incorporated into the HSR by species-specific Helitron insertions inC. elegans andC. briggsae and by strain-specific insertions among different wild isolates ofC. elegans. Our studies uncover previously unidentified targets of HSF-1 and show that Helitron insertions are responsible for rewiring and diversifying theCaenorhabditis HSR.
Source: eLife - Category: Biomedical Science Tags: Genetics and Genomics Source Type: research