Expression of Scapularisin-3 and Scapularisin-6 in tick tissues and cell lines. The expression pattern determined by PCR and visualised by agarose gel electrophoresis of Scapularisin-3 and Scapularisin-6 in I. scapularis salivary glands (SG), midgut (MG) and embryo-derived tick cell lines ISE6 and ISE18 is shown. Both defensins were expressed in SG. Scapularisin-6 was expressed in MG and neither of the two defensins was expressed by embryo-derived tick cells (ISE6 and ISE18) in vitro. (β-actin was used as a positive control).