Giant wood spider Nephila pilipes alters silk protein in response to prey variation
Journal
Journal of Experimental Biology
Journal Volume
208
Journal Issue
6
Pages
1053-1061
Date Issued
2005
Author(s)
Abstract
Recent studies have demonstrated that orb-weaving spiders may alter web structures, foraging localities or silk output in response to prey variations. In this study we conducted field surveys and food manipulations to examine whether orb-weaving spiders may also adjust the protein of silk to prey variations. A comparison of dragline silks collected from nine giant wood spider Nephila pilipes populations in Taiwan showed a spatial variation. The percentage of all amino acids (except alanine and glycine) exhibited significant differences among populations. A survey of prey composition also revealed a significant spatial variation among N. pilipes populations. To determine whether prey variation was responsible for silk protein variation, we fed N. pilipes with different types of prey (dipteran vs orthopteran) then compared the percentage of five major dragline amino acids and secondary structures. The results showed that dragline of N. pilipes fed with orthopteran prey contained significantly higher proline and glutamine but lower alanine. Congruent with this result were those from FTIR spectroscopy, which showed that dragline of N. pilipes fed with crickets exhibited significantly higher percentage of proline- and glutamine-containing β turns, and lower percentage of alanine-containing β sheet structures. Since the results of feeding manipulations showed that diet significantly affected the compositions of dragline silks, the observed spatial variation seemed to reflect the different types of prey these spiders had consumed. Results of this study thus indicated that orb-weaving spiders can alter dragline protein in response to prey variations.
Subjects
Dragline; Major ampullate gland; Nephila; Spider silk
Other Subjects
amino acid; analysis of variance; animal; chemistry; comparative study; diet; infrared spectroscopy; insect; physiology; predation; protein conformation; review; silk; spider; Taiwan; Amino Acids; Analysis of Variance; Animals; Diet; Insects; Predatory Behavior; Protein Conformation; Silk; Spectroscopy, Fourier Transform Infrared; Spiders; Taiwan; Araneae; Diptera; Gryllidae; Nephila; Nephila maculata; Orthoptera
Type
review