<p class="Body"><strong>Differential transcriptome profiling of the diapause and cold-responsive genes in unfed adult <em>Dermacentor silvarum</em> Olenev (Acari: Ixodidae)</strong></p><p class="Body"> </p>

Abstract

The tick Dermacentor silvarum mainly overwinters in northern China as an unfed adult entering diapause; however, little is known about the involvement of genes and pathways in summer diapause and overwintering adults of this species. Hence, we investigated the differential transcriptome profile of D. silvarum ticks’ diapause and cold-responsive genes and pathways during its summer diapause, overwintering, and questing/active stages. Through transcriptomic sequencing, a total of 136,740 unigenes were assembled, and 1,549, 2,196, and 2,125 differentially expressed genes (DEG) were identified in active and diapause, diapause and overwintering, and active and overwintering ticks, respectively. Between active and diapause ticks, 875 genes were up-regulated, while 674 genes were found down-regulated in diapause ticks. When compared with active ticks, overwintering ticks had 993 up-regulated genes and 1,132 down-regulated genes. Comparison between diapause and overwintering ticks revealed 745 up-regulated and 1,451 down-regulated genes in overwintering ticks. Gene Ontology analysis revealed that, among the active, diapause, and overwintering ticks, most of the DEGs in molecular function were enriched in catalytic activity and hydrolase activity. In the cellular component, most DEGs were assigned to the integral component of the cell membrane , whereas the oxidation-reduction process was the most enriched among biological processes. In addition, the lysosome pathway was the most enriched pathway identified in KEGG pathway analysis. The above results deepened our understanding of the mechanism underlying diapause and overwintering adaptation of ticks, which is important for integrative prevention and control of ticks and tick-borne diseases.

Metabolomic and transcriptomic responses of ticks during recovery from cold shock reveal mechanisms of survival

“…In overwintering D. silvarum, molecular functions such as catalytic activity and binding, cellular components including membrane, and biological processes such as oxidation-reduction process and metabolic process were highly enriched GO terms (as compared with summer ticks) (Yu et al, 2020). For most of the GO terms enriched in winter D. silvarum, there were genes that were upregulated in our RCH recovery ticks that matched those categories (Fig.…”

“…If the valine in ticks is accumulated during the recovery period, it may serve a role in the restoration of homeostasis and/or may contribute to survival of subsequent cold exposure. Alternatively, it is possible that the protein breakdown is due to a disruption in homeostasis caused by CS damage, or proteolysis may be a common stress response in ticks as dehydrated D. variabilis (Rosendale et al, 2016b) and overwintering D. silvarum (Yu et al, 2020) also show an upregulation of this pathway.…”

Functional implication of heat shock protein 70/90 and tubulin in cold stress of Dermacentor silvarum

“…All the primers were designed with DNAMAN (Lynnon Biosoft, San Ramon, CA, USA) and Primer Premier version 5.0 for Windows (Premier Biosoft International, Palo Alto, CA, USA) (Additional file 4 : Table S1). Information from the GenBank sequences and transcriptomic data [ 42 ] was used to design the primers for target genes in D. silvarum .…”