Blood feeding triggers the terminal differentiation of precursor cells in tick salivary glands
- Sazzad Mahmood
- Stephen Lu
- Ana Beatriz Barletta Ferreira
- Markus Berger
- Oladele A. Oluwayiose
- Christine A. Schneider
- Jacqueline M. Leung
- Melina Garcia Guizzo
- Yixiang Zhang
- Randall Johnson
- Kevin W. Cormier
- Motoshi Suzuki
- Nathan T. Brandes
- Gwendolyn Cooper
- Joshua Gold
- Benjamin Schwarz
- Lisa R. Olano
- Justin Lack
- Carolina Barillas-Mury
- José M. Ribeiro
- Lucas Tirloni
2026-03-25
Ticks transmit a wide range of pathogens to humans. During blood feeding, they inject salivary proteins that suppress host immune responses, enabling prolonged feeding and pathogen transmission. A hallmark of this process is the dynamic reprogramming of salivary gene expression, known as the sialome switch. Here, we describe a previously unrecognized cellular mechanism underlying this phenomenon in two medically important tick species. Using integrated multi-omics and imaging approaches, we identified a conserved population of undifferentiated salivary gland precursor cells in unfed ticks. Upon host attachment, these precursors undergo terminal differentiation into specialized secretory subtypes through a conserved transcriptional and signaling framework that drives salivary gland activation and maturation. Unlike other blood-feeding arthropods, tick salivary glands dynamically remodel in response to host contact, producing saliva with a shifting composition. This study suggests the cellular basis of adult female tick salivary gland maturation and offers targets to disrupt feeding and pathogen transmission.