Water absorption through salivary gland type I acini in the blacklegged tick, Ixodes scapularis

PeerJ

article

Donghun Kim¹  Paulina Maldonado-Ruiz¹  Ludek Zurek¹  Yoonseong Park¹ 

[1] Department of Entomology, Kansas State University

关键词: Salivary gland;    Vector;    Rhodamine;    Water balance;   

DOI  :  10.7717/peerj.3984

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Tick salivary glands play critical roles in maintaining water balance for survival, as they eliminate excess water and ions during blood feeding on hosts. In the long duration of fasting in the off-host period, ticks secrete hygroscopic saliva into the mouth cavity to uptake atmospheric water vapor. Type I acini of tick salivary glands are speculated to be involved in secretion of hygroscopic saliva based on ultrastructure studies. However, we recently proposed that type I acini play a role in resorption of water/ions from the primary saliva produced by other salivary acini (i.e., types II and III) during the tick blood feeding phase. In this study, we tested the function of type I acini in unfed female Ixodes scapularis. The route of ingested water was tracked after forced feeding of water with fluorescent dye rhodamine123. We found that type-I acini of the salivary glands, but not type II and III, are responsible for water uptake. In addition, the ingestion of water through the midgut was also observed. Injection or feeding of ouabain, a Na/K-ATPase inhibitor, suppressed water absorption in type I acini. When I. scapularis was offered a droplet of water, ticks rarely imbibed water directly (5%), while some approached the water droplet to use the high humidity formed in the vicinity of the droplet (23%). We conclude that during both on- and off-host stages, type I acini in salivary glands of female Ixodes scapularis absorb water and ions.

【 授权许可】

CC BY