Tick (Acari: Ixodidae) attachment cement and salivary gland cells contain similar immunoreactive polypeptides

A specific antiserum (12C) raised to a 90-kDa immunogenic component of salivary glands of the tick Rhipicephalus appendiculatus recognized similar 90-kDa polypeptides from salivary glands of the American dog tick, Dermacentor variabilis, and the lone star tick, Amblyomma americanum, as well as 70-kDa polypeptides in the cement of D. variabilis, A. americanum, and R. sanguineus (brown dog tick). The reduction in size of the polypeptide for these ticks suggests that it is modified in some way during or after secretion. Immunostaining of salivary glands of unfed- and partially-fed female D. variabilis localized an immunoreactive protein in the d- and e-cells of the type III acini. The quantity of label in granules of glands from unfed ticks was visibly greater than in the granules of glands from partially fed ticks, suggesting that this component is secreted within the first 2 d of feeding. Collectively, these data support the conclusion that a 90-kDa polypeptide of saliva is conserved among ixodid tick genera and is a component of the attachment cement.