Fig. 6

The transcriptional level of caspases was reduced in the dsRhEcR-treated group in Rhipicephalus haemaphysaloides. Using qRT-PCR, relative RNA levels of related genes were measured. The relative RNA levels of functional ecdysone receptors a RhEcR and b RhUSP and apoptosis signaling pathways c RhCaspase7, d RhCaspase8, and e RhCaspase9 in the salivary gland were analyzed during the feeding period and in post-engorged female ticks. At the beginning of salivary gland degeneration, RhCaspase7, RhCaspase8, and RhCaspase9 were downregulated. At all of the test time points, the RhCaspase7 RNA level was lower than that in the control group. Treatment with dsRhEcR downregulated the RNA levels of apoptosis-related genes in the salivary gland. This showed inhibition and degeneration of the salivary gland in dsRhEcR-treated ticks. The data represent the mean ± SD of the experiments (10 ticks/time point) performed in triplicate and normalized to EF1α, and two-tailed Student’s t-tests were used to identify significant differences between groups (RhEcR-Fed3: t = 5.815, df = 2, P = 0.0283; RhEcR-Fed5: t = 11.68, df = 2, P = 0.0072; RhEcR-Fed7: t = 6.264, df = 2, P = 0.0246; RhUSP-Fed3: t = 4.247, df = 2, P = 0.0512; RhUSP-Fed5: t = 12.19, df = 2, P = 0.0067; RhUSP-Fed7: t = 9.101, df = 2, P = 0.0119; RhCaspase7-Fed3: t = 4.916, df = 2, P = 0.0390; RhCaspase7-Fed5: t = 8.542, df = 2, P = 0.0134; RhCaspase7-Fed7: t = 5.716, df = 2, P = 0.0293; RhCaspase8-Fed3: t = 7.832, df = 2, P = 0.0159; RhCaspase8-Fed5: t = 0.2845, df = 2, P = 0.8028; RhCaspase8-Fed7: t = 6.299, df = 2, P = 0.0243; RhCaspase9-Fed3: t = 11.69, df = 2, P = 0.0072; RhCaspase9-Fed5: t = 26.66, df = 2, P = 0.0014; RhCaspase9-Fed7: t = 6.933, df = 2, P = 0.0202, ns P > 0.05, *P < 0.05, **P < 0.01)