Exploring the transcriptome of immature stages of Ornithodoros hermsi, the soft-tick vector of tick-borne relapsing fever

• Published in: Scientific reports 2024-05, Vol.14 (1), p.12466-12, Article 12466
• Main Authors: de Sousa-Paula, Lucas C., Berger, Markus, Talyuli, Octavio A. C., Schwartz, Cindi L., Saturday, Greg A., Ribeiro, José M. C., Tirloni, Lucas
• Format: Article
• Language: English
• Subjects: 631/337/2019; 631/601/1466; Animals; Arachnids; Developmental stages; Feeding Behavior; Gene Expression Profiling; Hematophagy; Hemorrhage; Humanities and Social Sciences; Larva - genetics; Larvae; multidisciplinary; Nymph - genetics; Nymph - growth & development; Ornithodoros; Ornithodoros - genetics; Ornithodoros - growth & development; Relapsing fever; Relapsing Fever - microbiology; Science; Science (multidisciplinary); Tick-borne diseases; Transcription; Transcriptome; Transcriptomes; Transcriptomics
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-62732-6

Blood-feeding behavior has independently evolved in arthropods multiple times. Unlike hard ticks, soft ticks employ a rapid-feeding strategy for hematophagy, and there are comparatively limited studies on the transcriptomes of these organisms. This study investigates the soft tick Ornithodoros hermsi , conducting histopathological examinations at bitten skin sites and tick whole-body transcriptomic analyses across various developmental and feeding stages, including larvae, 1st-nymphal, and 2nd-nymphal stages. The results revealed the ability of O. hermsi to induce skin hemorrhage at the bite sites. Transcriptomic analyses identified three consistent transcriptional profiles: unfed, early-fed (6 h, 12 h, 24 h), and late-fed (5 days). The unfed profile exhibited high transcriptional activity across most of the functional classes annotated. In contrast, early-fed stages exhibited decreased expression of most functional classes, except for the unknown, which is highly expressed. Finally, transcriptional expression of most functional classes increased in the late-fed groups, resembling the baseline expression observed in the unfed groups. These findings highlight intense pre-feeding transcriptional activity in O . hermsi ticks, aligning with their rapid-feeding strategy. Moreover, besides shedding light on the temporal dynamics of key pathways during blood meal processing and tick development, this study contributes significantly to the transcriptome repertoire of a medically relevant soft tick species with relatively limited prior knowledge.