Molecular characterization, expression pattern, and ligand-binding property of three odorant binding protein genes from Dendrolimus tabulaeformis.

Sufang Zhang,Zhen Zhang,Xiangbo Kong,Hongbin Wang

doi:10.1007/s10886-014-0412-6

Abstract

Odorant binding proteins (OBPs) play important roles in insect olfactory processes. The Chinese pine caterpillar moth, Dendrolimus tabulaeformis (Lepidoptera, Lasiocampidae) is a serious economic pest in China, and the pheromones of this species have been identified to monitor their presence. However, the molecular mechanisms by which D. tabulaeformis perceive pheromones and host volatiles remain unknown. In this study, we identified and characterized three new OBPs, including one pheromone binding protein (PBP1) and two general odor binding proteins (GOBPs), from antennal cDNA of D. tabulaeformis. The deduced amino acid sequences of DtabPBP1, DtabGOBP1, and DtabGOBP2 revealed mature proteins of 140, 147, and 140 amino acids, respectively. Each has six cysteine residues in conserved positions relative to other known OBPs. Amino-acid alignments indicated that the two GOBPs are more conserved (DtabGOBP1 is 52.9–67.4 % identical to orthologs from other Lepidoptera, and DtabGOBP2 is 55.2–81.8 % identical) than the PBP (32.5–46.0 %). Real-time PCR indicated tissue- and sex-specific expression patterns of the three genes. DtabPBP1 was mainly expressed in the antennae of males, whereas female antennae had only 1.09 % the expression in male antennae. Both DtabGOBP1 and DtabGOBP2 were more highly expressed in antennae than in other tissues, while DtabGOBP1 was more abundant in male antennae and DtabGOBP2 in female antennae. In addition, the binding specificities of the three proteins were investigated, and all three OBPs exhibited high binding affinities for the pheromone component (5Z,7E)-5,7-dodecadien-1-yl propionate (Z5,E7-12:OPr). This suggests a role in binding pheromone for GOBPs, as well as PBP1, in D. tabulaeformis.Electronic supplementary materialThe online version of this article (doi:10.1007/s10886-014-0412-6) contains supplementary material, which is available to authorized users.

Highlights

The Chinese pine caterpillar moth, Dendrolimus tabulaeformis (Lepidoptera, Lasiocampidae) is a serious economic pest in northern China (Yan 1992)
Identification and Characterization of PBP1, GOBP1, and GOBP2 cDNA from D. tabulaeformis The PCR using degenerate primers was designed based on the conserved amino acid regions in pheromone-binding protein (PBP), GOBP1, and GOBP2 genes of other Lepidopterans
One PBP and two general odor binding proteins (GOBPs) were identified from the antennae of D. tabulaeformis

Summary

Introduction

The Chinese pine caterpillar moth, Dendrolimus tabulaeformis (Lepidoptera, Lasiocampidae) is a serious economic pest in northern China (Yan 1992). Aerial treatments with chemical and bacterial insecticides are the main methods of controlling D. tabulaeformis, and people even manually collect the cocoons during outbreak years. These methods are either environmentally unfriendly or inefficient. Chemical signals are the primary basis of interactions between insects and their surroundings, and olfaction is a major communication system in insect (de Bruyne and Baker 2008; Touhara and Vosshall 2009) Environmental volatiles, such as host plant volatiles, and pheromones from potential mates are two important kinds of chemical attractants for insects (Bruce et al 2005; Karlson and Butenandt 1959). The sex pheromones of D. tabulaeformis were identified; they are (5Z,7E)-5,7-dodecadien-1-yl acetate (Z5,E712:OAc), (5Z,7E)-5,7-dodecadien-1-ol (Z5,E7-12:OH), and

Methods

Results

Conclusion