Differential expression of heat shock protein genes in Rhipicephalus sanguineus (Acari: Ixodidae) exposed to temperature and humidity variations.

The brown dog tick (Rhipicephalus sanguineus), a well-recognized parasite that is an important vector of many pathogens, widely distributed in the world, can be found in dogs and many other host animals, including humans. However, the response of this species to climate changes is not fully understood yet. Therefore, this study aimed to analyze the expression of the genes encoding for hsp20 and hsp70 of nymphs and eggs of R. sanguineus in response to different relative humidity and temperature. While no significant differences were observed in hsp70 levels in nymphs, striking variations were found for hsp20. On the contrary, significant differences were found on the expression levels of both HSPs when exposed at different treatments. Expression of hsp20 was more affected by relative humidity than by temperature, which could imply that hsp20 may have a more critical protective role during vulnerable developmental stages of the tick than hsp70.