Fig. 4.
Identification of defensive peptides in Dasymutilla venoms. a Application of D. klugii venom (100 μg/mL) to DRG cells produced a rapid, non-cell-specific increase in [Ca2+]i. Micrographs show recordings before and 2 min after venom application. Scale bar = 100 μm. b Each trace represents the fluorescence of a single cell in the field of view, with the average of all traces displayed in color. c D. klugii venom (250 μg) was fractionated using reversed-phase HPLC and each fraction was screened for activity on F11 cells, which yielded two active fractions (f8 and f18). Traces corresponding to the change in [Ca2+]i for f8 and f18, and representing the mean of two experiments, are displayed in the insets. d Active fractions were identified as Dk13a (D. klugii f8) and Dk5a (D. klugii f18). Alignment of Dk5a and Dk13a with homologous peptides from the venom of other species. Lysine/arginine and aspartate/glutamate are colored in blue and red, respectively; *, C-terminal amidation. e Intraplantar injection of synthetic Dk13a and Dk5a (600 pmol) induced spontaneous nocifensive behavior in mice. Data are expressed as mean ± SEM (n = 3). i Intrathoracic injection of crude D. klugii or D. gloriosa venom (15 μg/g) reduced survival probability in Apis mellifera (n = 4–6 per condition). (j) Intrathoracic injection of Dg3a, Dg6a, Dk5a and Dk13a, but not Dg1a, Dg2a, Dg4a, Dg5a and Dg7a (15 nmol/g) reduced survival probability in Apis mellifera (n = 4–6 per condition)