A Diminish the chances of Mediterranean fruit fly Ceratitis capitata eggs surviving by suppressing the expression of the heat shock protein 27 gene (Hsp27).

Abstract

The hypothesized role of stress-inducible heat shock proteins is to act as a buffer against environmental variations and affect fitness in suboptimal conditions. Our study examining the functions of heat shock protein 27 (Hsp27) in the eggs of the Mediterranean fruit fly (Ceratitis capitata). We utilized double-stranded RNA, specifically targeting the Hsp27 gene, to reduce its expression and assessed the consequent impact on egg viability. The investigation included the examination of early eggs (less than 6 hours post-laying) and late eggs (more than 42 hours post-laying), using varying concentrations (0.02, 0.1, and 0.2 µg/µL) of Hsp27 dsRNA. Control groups of eggs were dsRNA of ATPase, Cctra-2, or phosphate buffer solution (ph-B-S). Down-regulating Hsp27 dsRNA reduced the hatching rate of the eggs compared to the hatching rate in the control groups, especially in the ph-B-S group. The early eggs were more affected than the late eggs after soaking with Hsp27 dsRNA, where the Hsp27 dsRNA decreased the hatching rates to 12.91% early. The tested concentration of 0.2 µg/µL of Hsp27 dsRNA was achieved with the most significant reduction of 2.75 in egg viability. The sex ratio of insects hatched from treated eggs was investigated after hatching. After the down-regulation of Hsp27, there was no significant effect of the Hsp27 down-regulation on the sex ratio.

Keywords

• Double-stranded RNA (dsRNA); biological control; insect eggs; sex ratio