Molecular characterization of class I histone deacetylases and their expression in response to thermal and oxidative stresses in the red flour beetle, Tribolium castaneum.

Reversible acetylation of core histones plays an important role in the epigenetic regulation of gene transcription, and is controlled by the action of histone acetyltransferases (HATs) and histone deacetylases (HDACs). While HDACs have been well studied in Drosophila melanogaster, information from insect pests is still limited. In the current study, we cloned and characterized three class I enzymes, TcHDAC1, TcHDAC 3 and TcHDAC 8, in the red flour beetle, Tribolium castaneum. Expression profiling showed that T. castaneum HDAC genes are expressed in all developmental stages and tissues examined. A dramatic increase of mRNA expression level was observed from prepupae to 1-day-old pupae for all three T. castaneum HDAC genes. Both TcHDAC1 and TcHDAC3 exhibited the highest mRNA expression levels in thorax, whereas TcHDAC8 was highly expressed in fat body. Furthermore, T. castaneum HDAC genes were found to respond to heat, cold and oxidative stresses. While the heat-stress treatment decreased the mRNA expression levels of T. castaneum HDAC genes, their transcripts were induced by paraquat treatment. These results suggest a possible role for class I HDAC genes in the epigenetic regulation of T. castaneum development and stress responses.