Differential resistance of heat shock proteins (HSP70 and HSP90) in Anopheles culicifacies mosquitoes with respect to variations in temperature in India.

BACKGROUND

Odisha, formerly known as Orissa, is a state on India's eastern coast along the Bay of Bengal. Odisha remains relatively less well known internationally, yet it plays a crucial role in public health and environmental research, particularly in vector-borne disease surveillance and climate vulnerability studies. Odisha experiences extreme temperatures, and Anopheles culicifacies mosquitoes are known vectors of malaria. In response to heat stress, mosquitoes express multiple heat shock proteins (HSPs), which can modify their gene expression.

METHODS

To investigate HSP expression in mosquitoes, we exposed laboratory-reared mosquitoes to heat shock at various durations and temperatures to assess how the HSP gene contributes to heat resistance. Insectary-reared female An. culicifacies served as controls. We quantified the expression of Hsp70 and Hsp90 using quantitative real-time polymerase chain reaction (qRT-PCR), comparing relative transcript expression levels with insectary-reared controls via the 2-ΔΔCt method.

RESULTS

The mean expression levels of the Hsp70 and Hsp90 genes were 3.75 ± 3.60 and 1.28 ± 1.09-fold, respectively, compared to the reference gene (actin). Relative Hsp70 expression levels were ten times higher than those of Hsp90. Statistical analysis revealed that the Hsp70 and Hsp90 genes were significantly upregulated at 40 °C and 42 °C after 1 h and 0.5-hour exposures, respectively.

CONCLUSION

HSPs can serve as an important biomarker and may play a crucial role in protecting and enhancing the survival of An. culicifacies in the extreme temperatures of Odisha.