ABSTRACT Ticks are blood-feeding ectoparasites but spend most of their life off-host where they may have to tolerate low winter temperatures. Rapid cold hardening (RCH) is a process commonly used by arthropods, including ticks, to improve survival of acute low temperature exposure. However, little is known about the underlying mechanisms in ticks associated with RCH, cold shock and recovery from these stresses. In the present study, we investigated the extent to which RCH influences gene expression and metabolism during recovery from cold stress in Dermacentor variabilis, the American dog tick, using a combined transcriptomics and metabolomics approach. Following recovery from RCH, 1860 genes were differentially expressed in ticks, whereas only 99 genes responded during recovery to direct cold shock. Recovery from RCH resulted in an upregulation of various pathways associated with ion binding, transport, metabolism and cellular structures seen in the response of other arthropods to cold. The accumulation of various metabolites, including several amino acids and betaine, corresponded to transcriptional shifts in the pathways associated with these molecules, suggesting congruent metabolome and transcriptome changes. Ticks, D. variabilis and Amblyomma maculatum, receiving exogenous betaine and valine demonstrated enhanced cold tolerance, suggesting cryoprotective effects of these metabolites. Overall, many of the responses during recovery from cold shock in ticks were similar to those observed in other arthropods, but several adjustments may be distinct from the responses in other currently examined taxa.
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Function and evolution of the aquaporin IsAQP1 in the Lyme disease vector Ixodes scapularis
Ticks are important vectors of pathogenic viruses, bacteria, and protozoans to humans, wildlife, and domestic animals. Due to their life cycles, ticks face significant challenges related to water homeostasis. When blood‐feeding, they must excrete water and ions, but when off‐host (for stretches lasting several months), they must conserve water to avoid desiccation. Aquaporins (AQPs), a family of membrane‐bound water channels, are key players in osmoregulation in many animals but remain poorly characterized in ticks. Here, we bioinformatically identified AQP‐like genes from the deer tick
- Award ID(s):
- 1645331
- NSF-PAR ID:
- 10428796
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Insect Molecular Biology
- Volume:
- 32
- Issue:
- 4
- ISSN:
- 0962-1075
- Page Range / eLocation ID:
- p. 329-339
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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