Heat shock genes in the stingless bee Melipona interrupta (Hymenoptera, Meliponini)
Heat shock proteins (HSPs) are highly conserved molecules across all plant and animal species. In insects, HSPs are expressed in response to biotic and abiotic stressors and have a well characterized expression pattern in response to heat stress, especially heat shock genes Hsp60, 70 and 90. Temperature affects many aspects of eusocial Hymenoptera, including the stingless bees (Apidae, Meliponini). Consequently, these insects have developed thermal adaptation mechanisms, including thermoregulation. However, this ability decreases when there is deviation from the optimum temperature, compromising colony survival. The study of molecular responses to heat shock stress can be important for the preservation of these pollinizers. We identified and validated in silico the genes encoding HSP60, 70 and 90 in Melipona interrupta, one of the main stingless bees used for honey production in the Amazon region. cDNA fragments of males, workers and queen bees at the white-eyed pupal stage were amplified using degenerate primers. After sequencing, aligning and editing, the sequences were compared with public genomic databases for in silico validation. One fragment of Hsp60, three fragments of Hsp70 and two fragments of Hsp90 were obtained for M. interrupta. These fragments showed 100% similarity with mitochondrial sequences of HSP60 and cytosolic sequences of HSP70 and HSP90 of bees of the genera Apis and Bombus. Therefore, the fragments obtained in this study correspond to parts of HSP60 (mitochondria), HSP70 and HSP90 (cytosol) in white-eyed pupae of M. interrupta. The nucleotide sequences of these fragments did not vary between genders and castes. Our validation in silico of the genes encoding HSPs will be useful for future investigations regarding differential expression of HSPs in response to environmental factors that affect the development, maintenance and survival of stingless bee colonies in the Amazon.